serial interface buses

DIMM Module Pin Outs

2011-02-23T20:55:00.002-05:00

In order to reduce the page size of the DIMM memory module pin out, the page was divided up into two different pages. the original page address now holds the pin out for the Rear Side 168-pin DIMM Pin Out, while the new page address holds the Front Side 168-pin DIMM Pin Out.

The change reduces a 56k byte file into two 35k byte files. The change is not so much for a web visitor but for the Google system checking page loading times. So now the two pages load twice as fast; however both pages also look almost identical. So it may well be that Google will not rank the new page in terms of searches, but the original page should still rank. The web site only has several other pages that are larger in size, not including graphic files. Most of the larger pages all relate to interface bus pin-outs, except for the 144 Pin SODIMM module which is at 40 k bytes. However the 144-pin SODIMM is one big table while the 168-pin DIMM pin outs were a set of 4 different tables for front and back pins.

Most pages on the site are around the 10 to 15k size, not including pic files.

While checking the page stats, I think I found a page with no incoming links to it?
Buffered 168 pin DIMM Modules.

Looks like the page linking to it had an address typo. Google Analytics indicates that the page has only received 2 pages views between 2007 and 2010. With that few page views the page gets lost in the report of web addresses vs page views. Down around the 2 page view section the report is full of 'wrong page addresses' which are not real pages.

Engineering Dictionary

2011-02-09T09:03:00.000-05:00

I'm adding new technical terms to the Engineering Dictionary all the time. I try to keep the pages a certain length, so from time to time I divide them up to keep the page lengths about the same.
One new page starts with the Pull-Down Resistor Definition, which was divided off from the page starting with the Definition of PRBS. It doesn't matter which page a technical definition is on, except for page length, because at the top of each page is a directory for that particular letter. So a visitor can quickly move to the correct page with out having to scroll through a number of engineering definitions they may not be interested in.
A second update was made to the page starting with the PCB Term Via, as in a plated hole in a printed wiring board. The new follow on page starts with the Definition of Volt.

I don't divide the pages up that often because there are a number of issues with making a new page from an existing page, plus the pages grow in size slowly. Of course it takes a few weeks for the new page to be found by the search engines. With Google that also means that it will be at least 3 months for the new listing to receive a page rank. Following that lack of page rank also implies that terms that were search-able may no longer be found in a search, until they get a little page rank.

Another problem with this type of new page is that the page that was just generated appears to have duplicate content to the page it was derived from. Remember the existing page was already in a search engine cache, so when the new page shows up it looks just like the 'older' page. So it takes some time before both pages are spidered [by the search engines] and appear to be different. The bottom line is that any definitions residing on the new page are unreachable by the search engines for some months, new page or not.

Audio Circuit Diagrams

2011-02-02T11:15:00.000-05:00

Added a few pages covering audio controls a few weeks ago, looks like some have been indexed already.
Audio Base Adjustment.
Audio Treble Adjustment.
Audio Midrange Adjustment.
Audio Tone Adjustment.
Audio Loudness Adjustment.
A few of the additions provide some circuit analysis like the page covering Base control, while the page on Loudness just shows a simple circuit with no values. Same with the Tone control, just a circuit with no values. I've been wanting to add a audio control schematic for a while now, a partial schematic has been in my to-do list for months. So I'm just glad I finally got around to adding some data, partial or not. Each of the new pages is linked of each other and from the correct page in the Engineering Dictionary.

The companion site also has a few Audio Amplifier circuits which these could be applied to, and a Speaker Amplifier circuit.

Low Page Views During 2010

2011-01-24T18:51:00.001-05:00

Here are some pages that received little or no page views during 2010. These pages received 10 or less page views. There are hundreds of pages that never reached 365, or one page view a-day.

The FCIP protocol is brefly covered on a single page, with less than a paragraph of text which might explain why it receives no page views. The iSCSI Protocol page has the same problem, but with 15 page hits for the year.

A page covering 2N3485 High Temperature Operation received 8 page views. A failed section that receives very few page views. It could be that many of the pages in this section cover transistors that are no longer used, or maybe not in mass production. In any case the data is no the site, if some one did want to use it, But I've been up dating these pages for three years now with little or no success. Same deal for Over-Driving a 2N4237 Transistor, with 9 page views.

Of course this list has to include one of the pages from the Manufacturers Directory, this one listing companies starting with Vm. Having no page rank after 5 years on the internet and 13 page views for all of 2010, but that fits the entire section.

The new page on Doppler Shift failed to receive any page hits. Another new page relating to TTL OR Gates, but this one looks to contain almost no data.

A section on how to design an equipment chassis contains a page about Water Sensors, maybe I should just remove it because it costs my server more in bandwidth than I receive in page views. Another section around the same size covers Interface Buses in alphabetic order is doing about the same, guess no one needed that enhancement.

The content page for [page deleted] had 8 page views for all of 2010. It's a small section of a dozen pages that did much better a few years back, and I'm not sure why the page views have declined so bad. But that;s ok, because I only wrote it as a start to help a friend get into web development. The pages have zero to do with engineering.

transistor Overheating

2010-12-10T18:06:00.000-05:00

There were a number of pages added a few years ago that covered temperature derating of transistors. The pages either covered power derating for air temperature or component case temperature. Anyway none of those pages are doing very well, in fact most don't even get a page-view per day.

It's not like I'm going to remove the pages or anything, but I would like to see more activity.
Transistor Related pages:

2N3441 NPN Transistor.
2N4931 PNP Transistor.
2N5003 PNP Transistor.
2N5002 NPN Transistor.
2N6691 NPN transistor.

In the hope that some day they might start doing better I keep up-dating them, although after 2 years of updates it appears that they may never take-off. These are links to pages that were never mentioned in this blog, so they are linked now. There are a number of others that have never been linked, but what's the point.

There are groups of other pages that don't do that well either.
.

IC Circuit Functions

2010-12-03T20:29:00.000-05:00

I was checking page visits for the year and found a number of new pages not getting any page views, and that have not been blogged about yet. I'm sure there are more but these pages received under 10 page views for the year.

Under the IC Functional Schematics;
Dual Input NOR Gate.
Dual Input XOR Gate.
8-Bit Latch.
MICA Capacitor Part Marking.
Styles of Capacitor Trimmers.

It's a bit late for any of these pages to help with the year end numbers, and the fact that they received less than 10 page views means they wouldn't put a dent in the numbers any way. But I'll blog about the new additions, but I think I added these pages a few months ago. I don't even think these pages will end up with 365 page views next year either. However sometimes is nice to have a page to round out a topic, it not really just about page views.

Glue Logic Functions

2010-12-02T18:44:00.000-05:00

About five months ago I started a new section covering basic IC functions. Of course when I started it, the section only consisted of a few pages but every month of so I add another page. Better yet I go back to one of the previous page addition and add more data.

So a week or so I added a new page covering the 74L121 Monostable Multivibrator [also 74L122]. In addition a sub page to hold the 74L121 Timing Graphs, which were a bit larger to fit on the same page.

These new pages relate to a few others already listed; Transistor One Shots, and a CMOS One Shot IC, and the 555 One Shot.

I think the newest page before that covered Hex Inverter ICs. Before that I think it was Bus Transceiver ICs. The point is that the section is slowly growing in size, and content. Engineering Topics home.

------------------------------------

Why are pages getting no visitors

2010-11-04T12:27:00.000-04:00

So I'm checking pages, just to see how they are doing this year from last year. Some aren't doing well with a drop in page views while other pages are just new.

Rotor Diagram, 2 month old page with just 5 page views.
Sample and Hold Definition, I think another new page with 5 views.
Distortion Definition. Yet another 3 month old page with no page views.

I'm using Google Web Master Tools to check page views, and there are misspelled pages getting more hits than these pages. Of course the misspelled one just show a 404 page not found.

Again two more new pages with only 7 page views. The real issue is that half of those page visits must be from me. So the rule is adding a new page may not bring in any new visitors to the site, at least in the short run. Having to wait two or three months just to get a few page views takes a little planing ahead, or at least not really needing additional page views any time soon.
Shrouded Header Definition. does not appear to be index yet
Unshrouded Header Definition. may not be index by Google yet either

Besides being a new page it appears that the few pages covering MIL-STD-100 are doing the worst or at least showing a decline in page views over last year.
BNC Adapter Definition, with maybe 15 page views.
None of these new pages have any incoming links, so the low views also indicate that no one already on the site are viewing these pages.
SCSI Interface Diagram. maybe 20 page views.
They also don't appear in a Google search yet which also indicates they may not have been spidered by Google yet. Google reads between 300 and 500 pages a day and I only have maybe 2000 pages, so you would think that within a week any new page would be spidered. However this two month old page does show up; What is a Tee Connector.

So I guess my advice would be to wait six months before a new page starts bring in any additional page views. And that only counts if the page has something to offer, some of my new pages have very little text which is what the search engine needs to rank a page.

How to Mount a Resistor

2010-10-13T14:15:00.000-04:00

I added a new page to cover some issues and things to consider when mounting a resistor to a Printed Wiring Board; as Resistor Mounting. This new page compliments a number of other resistor related pages including Resistor Lead Length, and the dictionary entry on Resistor Mounting Considerations.

Most of the PCB mounting issues should deal with through hole resistors and not surface mount resistors, but I'm not done writing the page yet. In most cases mounting issues for surface mount resistors is provided in the data sheet, which isn't true for through hole resistors. There are just to many ways to mount through hole resistors to include all the different variations in the data sheet.

I'll keep working a bit on the page today and then get back to it on the next time working that section of the web site.

Doppler Shift Frequency

2010-09-07T11:51:00.000-04:00

One of the new pages added a few weeks ago but never entered here related to Doppler Shift Definitions. I think the only page that links to it is the Doppler Definition in the dictionary of Radar terms. However because these new additions have not been crawled yet I can't be sure.

Anyway I came across the page so I listed it here, but it was added a week ago..

What is a Varistor

2010-09-03T20:12:00.000-04:00

Added a new page to better cover the Definition of a Varistor. I had a graphic of the body of a varistor along with its dimensions and I figured it would be better just to place it on a different page, instead of trying to fit it on a current page. So the page has a few graphics and so far the same definition that was already on the site.

There are a number of pages that link in; Companies that make Varistors, Resistor Definitions, Definition of a MOV, and the original Varistor Definition. Of course the Varistor page was also added the site map which holds all the pages address located on the Engineering Site. The site-map is also located off-site, at another web address.

So that's not a bad start with four incoming page links, this blog posting, an external link from the sitemap and a few graphics. Ok, not that much text, that will change in time. Better than a lot of other pages just starting off.

FMVSS138 Tire Pressure Monitoring System

2010-08-31T07:44:00.000-04:00

I was scanning the web yesterday and I came across a new vehicle interface, or maybe a vehicle system. The new interface is called the Tire Pressure Monitoring System or TPMS. The TPMS standard requires cars and trucks to have an early warning system to alert the driver that one or more tires on the vehicle is below their rated tire pressure. The standard went into effect around 2006, but this was the first I ever heard of it. I drive a 2006 Ford Mustang but I don't remember ever seeing it light, so it didn't make it to my model year.

The links pointing to the page include a 'T' Buses page, Electrical Interface Buses page the Engineering Acronyms page and the Definition of Torque page [first term on the page].

So we get another idiot light on our dash-board. However the TPMS light shows a tire to indicate a 'flat' instead of the engine-symbol light used by OBDII which nobody could ever figure out [check engine]. Now TPMS really indicates low tire pressure and not a flat, but one of the possible symbols appears to be a flat tire

Now it's not really an electrical bus, but it could be an electrical interface so that's why I listed it. I also added the spec to the web site so I wouldn't have to try and figure out what it was a few years from now. Apparently this standard does not really depend on any defined electrical or physical interface, it just has to perform its function.

74244 Octal Buffer

2010-08-22T19:06:00.000-04:00

Added a new page to show some details regarding the 74244 Octal Buffer. I was adding the page to have a link of one of the interface bus pages, but now I can't remember which interface uses the 74244 buffer. This particular buffer is a 74HCT244 which comes in a 20-pin PSOP, so a link from that page points to it too.

A link also points in from the main Functional IC Schematics page, and the individual page that covers 16-bit Buffer ICs. Like all other new pages I also added a link to the Engineering Sitemap for the Engineering Web Portal.

The link text used for the last two links are used so the search engine sees something other than a link to 'home' or 'sitemap'.

Logic True Tables

2010-08-19T12:00:00.000-04:00

I added a new page to hold a Glue Logic Truth Table covering each of the standard logic functions. The graphic already resided on the web site but was accessed by link to a graphic stored out on Picasa. So no new data was added, just moved onto a new page to hold the graphic. So far the new page is linked from the two other pages that had already pointed to the graphic; Definition of Triac [first term on the page], and the page on Glue Logic Timing.

So the Engineering Portal gets a new page, but at the same time it should be a page that will see little if any visitors. It's a common search term with no page text so maybe it will get some internal traffic, but should not see any from a search engine.

The point was not to generate a page which will never been seen. The original graphic was a 100k bit-map file stored out on Picasa, while the new file is stored on my server and only takes up 30k bits. So my server will see a 30k hit each time the page is viewed, it was zero while the pic file was stored off-site.

It's Google's view that a file on another server requires another DNS look-up [to find it] which slows the site down, and of course the new file is 70k smaller. Google started to also rate web sites on speed in addition to all the other things Google rates a site on. So this change makes the site appear faster to Google [a computer], but a visitor would never notice.

It's also better to have a picture embedded within the site and not just use a pointer out to some other server that holds pic files. The attached graphic is a pic of an AND gate and the true table for that AND gate.

Composite Video Connection

2010-08-17T16:33:00.000-04:00

I added a new page to cover Composite Video. The video interface was always listed on the Video Buses page, but because there were to many graphics associated with Composite Video I moved the topic to a new page. The link was also added to the Cable Buses page, Interface Buses 'C' and the list of all Interface Buses.

Except for the graphic no new information was added, this is an out of date interface. I still use it to connect to my older VHS tape decks, but I really stopped using the VHS stuff years ago.

I didn't check for any other page to page links pointing to the Composite Video topic, because the links on that page still work, or point to the new page. The attached graphic is one of the Sony Stereo AV receivers I have, I think this one is a 6.1 channel amplifier. I also have another 7.1 Sony receiver which is just about the same.

The receiver has 6 video channels using the Red/White/Yellow Composite video, including; TV/SAT, DVD, Video 1 and Video 2 and a single Yellow composite video connection for a monitor. Three channels of component video are also shown [Green/Blue/Red].

Low Profile BGA packages.

2010-08-11T22:51:00.000-04:00

I added a new page to cover a Low-Profile Ball Grid Array or LBGA. For some of these pages I provide package dimensions, but I didn't bother this time. I'm not even sure if the exact height of an LBGA is set or if it's more of an industry standard.

A related page covers a normal Ball Grid Array. Right now the page is a changed copy of the BGA page so I still may need to make some changes. But the important thing is that I got the new page added tonight before I got side track with fixing some other page. The new page is linked off the page that covers Surface Mount IC Packages.

Although BGA style packages are not used for processors in PCs they are used for a number of other components within a PC. Pin Grid Arrays are used for PC processors, while BGA style devices are used for memory and chip sets.

However BGA devices are used to great extend in industry, not because they always have more pins than a PGA but because BGAs are surface mount devices. Normally it's preferred to have all surface mount devices or all through hole devices during board construction.

High Power Transistor Packages

2010-07-26T20:05:00.000-04:00

Transistor packages usually use the nomenclature TO-xx, where TO stands for Transistor Outline. There are a number of transistor packages that will handle high power or high current, but it also depends on the semiconductor inside the packages.

A number of different transistor packages have been added over the last month, several can handle higher power loads. One package style is the TO-3 flange mount body. The TO-3 style dissipates a lot of heat because of the large metal package and because the metal flange is normally mounted to an even larger metal plate to dissipate even more heat. The most common TO-3 package holds two leads, with the case acting as the third terminal. Two additional new TO-3 related pages were added; the first a 4-lead TO-3 package, and the second an 8-lead TO-3 package.

Another through hole style high power package is the TO-220, although this one has a metal tab to dissipate heat. The 3 terminal package already resided on the site; however a 5-terminal TO-220 and a 7-Lead TO-220 package were added. The 7-leaded package has staggered leads, and there's an additional 5-Staggered Terminal TO-220 package to compliment it. Either of the new packages are designed to hold more than just a single transistor or FET; operational amplifiers in the case of the TO-3 package or regulators in the case of the TO-220 packages.

The other high power transistor case is the TO-263, or the surface mount version of the TO-220. There's a 3-terminal version, a 5-Terminal TO-263 package and a 7-Terminal TO-263 package.

It's easy to determine the number of pins required for a particular package, normally the function will dictate the number of leads. However it's a bit harder to pick the correct package style. So these are a few of the transistor package styles designed to dissipate high heat on the site.

Issues Realting to How to Derate Transistors and Resulting Failures

2010-07-16T17:48:00.000-04:00

There are two main pages in this section of the web site; How to derate Transistors by Temperature [Power x Temperature], and Diode Derating [Current x Temperature]. An interrelated page details how to read and Interpret Temperature Derating Curves, which works for diodes or transistors.

One of the new pages covers component mounting consideration, as Lead Length vs Thermal Resistance [power dissipation for leaded parts]. This particular topic shows why lead length is an important consideration in component power dissipation [in addition to increased circuit inductance]. A companion page covers Copper Pad Area vs Thermal Resistance, to address surface mount components.

The second new page covers Junction Temperature and Wirebond Life, the bond holding the wire between the semiconductor chip and package lead frame. Wire-Bond failure rate vs junction temperature is another way to cover the same topic as the derating charts already do; However, some derating curves do cover ambient temperature, heat-sink temperature and case temperature, in addition to junction temperature.

Related links include Maximum Safe Operating Area,
Over the last 30 days I have added almost 30 new pages, but they were so inter-related that I didn't think blogging about them would really help. Either each blog posting would read almost the same or they would have had almost no text. So I'll generated a new xml site-map for Google in a few weeks to catch the new pages, or wait until Google reads the pages their linked from. In the mean time I have been adding links to the new pages to the human readable [html] sitemap that covers the site [Engineering Site-Map].

So these are two of the nearly 30 new pages added over the last month. I may add them in a larger posting rather than one posting per new page.

TO-205 FET Package

2010-06-17T02:39:00.000-04:00

A new page holding a graphic of a TO-205 Metal Can was generated. This particular page gives the pinout for an FET, with the transistor pinout to be added later. As with any of the pages, this is linked off the FET Packages page.

SOT-23 Transistor Package

2010-06-16T18:24:00.000-04:00

Another transistor package page was just generated. The new page covers a SOT-23 Package [TO-236AA]. The physical dimensions are provided for the SOT-23 transistor package, but I'm not really sure if the TO-236AA would use the same numbers.

The SOT-23 page is linked off the Transistor Packages page, and was added to the Sitemap. That brings about a total of 23 pages in that section.

DO-7 Axial Lead Diode

2010-06-14T06:08:00.000-04:00

A new diode package was added today; DO-7 Axial Leaded Package. With the other component packages the DO-7 is linked off the Diode Package Styles page. These packages could be used by other two terminal components, but if they were the 'DO' which stands for Diode would not be used as part of the package name.

3-Terminal TO-247 Semiconductor Package

2010-06-13T12:04:00.000-04:00

Yet another new semiconductor package style added today. This time the component is a 3-Terminal TO-247AC Package. The 'AC' portion of the package type defines the package style depicted on the page. There are other styles of TO-247 components with many more than 3-leads. It's my impression that the TO-247 base number defines a package with an exposed metal plate on the rear of the component that connects directly to the semiconductor die; however I did not take the time to look that up.

The page graphic shows a package out-line and the dimensions for a TO-247AC and gives the pinout for an FET, but the text also provides the pin out for a transistor package.

As with any other similar package, any type of semiconductor could reside in the body of this case; however only a FET and BJT are given as examples. A few N-Channel FETs that use this package include; 2N7563, 2N7564, and 2N7565 [150 to 320 watts].

As with all new page additions to interfacebus, the page gets a mention in this blog, and to the external Engineering Sitemap. In addition there is always at least one internal link, in this case off the Transistor Packages page.

So every new page addition receives at least three incoming links, with two of the incoming links being external to the web site. However at last check the links on the site-map were 'no-follow', which means there is no credit for the link. The no-follow thing is Google's idea, and I have no control over that. Even if the sitemap does no really provide any search engine ranking it still works as a site-map, which is what it really is.

DO-123 Two-Terminal Surface Mount Package

2010-06-12T07:17:00.000-04:00

This time a 2-Terminal package was added to the Engineering Site. Under the main page covering Diode Packages, a link to the new page relating to the SOD-123 package style is inculded.

SOD-123 Die Bonding

TO-276 Three-Terminal Surface Mount Package

2010-06-11T18:51:00.000-04:00

What is a TO-276 device?
A 3-Terminal Surface Mount Component, shown on; TO-276 Transistor Package.
As discussed on that page the package may be used for any number of different semiconductors, but the term transistor is used in general. As with all the other related packages the TO-276 page is linked off the Transistor Packages page.

There's not much left to say, as this posts relates to the last two previous posts, which have already covered every thing.

This is the first surface mount package added to that section of the web site, all the other pages cover some type of through hole package. However I have had pending data on several other surface mount styles but the data has not been added yet because I been working other site issues ~ I'm not sure if I can add yet another package type in the next few days or not. Of course the Site-Map was also up-dated.

Transistor Die Bonding

Plastic Transistor Body

2010-06-10T13:21:00.000-04:00

Following yesterdays posting regarding the addition of the TO-63 transistor package I added yet another transistor package. This newest addition adds a Plastic TO-226 Transistor, very closely related to a Plastic TO-92.

The TO-226 is a common molded plastic case transistor; however because it's a plastic body it's not really used in any government specifications, so there are no BJT Dearting Curves provided as a link. In many cases I add these component bodies and indicate they are transistor devices, but any three terminal part could reside within these component shapes; including FETs and Transistors, or an SCR, Triac, or 3-terminal references or Temperature Sensors.... Of course some of these package will handle more power than others and may not accommodate higher current or voltage applications. Here is the top level page linking all Transistor Packages.

Both the new page on the TO-226 device and the TO-63 device added yesterday have been included in the Engineering SiteMap.

As normal with many new pages, this one is a copy of a preexisting page on the Engineering Site. However over time I'll add more data as I get back to that topic. The page on the TO-63 started out with a bit more data. I should be adding another related page on Friday.

TO-63 Transistor Package

2010-06-09T09:17:00.000-04:00

I just added a page showing the TO-63 Package Style. I'm not really sure how it was missing, because the drawing was being used on a few pages. As normal it's a copy of another page [TO-61 Case], but with a different graphic. Next time I get to it I'll add some data to the page.

The main page that shows a number of different links for; Transistor Cases.

Many of the pages that also use or point to the pages describing transistor packages is the How to Derate Transistors.

In general I indicate that this is a transistor package, but any three terminal device could reside in the package.

The graphic is a B-52 Control Panel, lower deck.
Much of the gear does not look like it fits, like it's a mix of different up-grades over the years.

Chassis Mount Power Resistor

2010-05-26T19:34:00.000-04:00

As part of the page covering How to Dearte a MIL-PRF-39009 Resistor, a new page was added to cover mounting area. The original MIL-39009 resistor page covered power dissipation vs ambient temperature, which is what most of the Component Dearting pages cover. More specifically output power by temperature is normally How Resistors are Derated.

This new page covers Derating MIL-PRF-39009 Resistors by Mounting Area. Or available power dissipation in watts compared to the area of the chassis the resistor is mounted to. This style of resistor is designed to be mounted to a metal surface to aid in dissipating power. So this is one of the few styles of resistors that shows a dearting chart that uses something other than ambient temperature. Although the original page does provide power dissipation vs temperature, the chart covering chassis mounting area is not related ~ use one chart or the other for derating purposes.

For reference here is another chart for Dearting a Variable Wire-Wound Resistor, and another for Derating Resistor Networks. But visiting any of these page links will show all the other styles or package options used and their derating charts. Most of the pages in this section have all the same page-to-page links.

Graphic:

MIL-PRF-39009 Chassis-Mount Power Resistor

Derating an IC

2010-05-24T09:15:00.000-04:00

Added a page to cover Derating Integrated Circuits. I think the page only has two sentences. The new page is linked off the main Component Derating page.

As time goes on, I'll add more information. I also up-dated some of the terms on the Transistor Derating page.

The entire derating section is increasing in page views, but not by the amount of time I've been putting into them..

555 Projects

2010-05-08T15:28:00.001-04:00

A few weeks back I added a few more pages related to the 555 timer. One circuit uses additional passive components to compensate for the tolerance of the external capacitor; 555 Timer Tolerance Compensation. The second page covers a Reducing Frequency 555 Oscillator. Both circuits are connected as Astable Multivibrator circuits.

Both pages were added to the engineering site map, but it does not appear that either page ever made it to this blog. I only noticed because both of those 555 pages have only received 2 visits in the last two months. It's almost like neither page has been index by Google? However I think the pages were only added 3 weeks ago.

For what ever reason my computer is slowing down to a crawl so I'll end this post and re-boot. Although I think the connection with the internet is going south. But I don't really want to reset the modem because a few of the open pages won't like it, including this blog as it auto saves about once a minute.

-- Ok that work, must have just been a memory leak.
----------------------------------------------------

Resistor Networks

2010-04-05T04:48:00.000-04:00

I went a head and added another page for a 20-pin Resistor Network. I added the link to a number of pages in that section, so many of those pages got updated. A 20 pin through-hole DIP seems like a pretty big package for the termination the package offers, but I guess if you have the board space.... Seems like the BGA package added the other day would be a better alternative. But of course the resistor arrangement is different, at least for the example provided.

I don't know what the application is for because the resistors seem like odd values, but there must be some common usage otherwise they wouldn't make it.

So any way it looks to be about 17 pages in this section, at least with the page address starting with resistor-network. All together they bring in a few visitors to the site, and most of the pages have a 50% bounce rate.

Resistor Array BGA Package

2010-04-03T11:27:00.000-04:00

A new page was just added to cover a BGA Resistor Array. The new Resistor Array is linked off the main Resistor Network page, which really covers a resistor network in a 16-pin DIP. I also added a link off the page covering Resistor Array Manufacturers, cause it seems like many of the other resistor network links are on that page.

I also added the page link to the SiteMap for the web site too.

None of these pages covering this topic are doing well. It could just be there is not a lot of search traffic for resistor network packages.

Looks like the last time I added a page to this topic was on Jan 12, as Resistor Networks. Then on Dec 3 as a DLCC Resistor Array. I've been slowly been added to this topic over the last few months.

I also up-dated the new Google search bar, if you happen to be following the other blog. The site search should work the same but the search bar looks a little different.

Panel Mount Fuse Holders

2010-04-02T08:44:00.000-04:00

I added a another page the other day, but because I didn't think it would ever produce any visits I waited till today before I blogged about it. Plus I just used all the other related links in the last posting. Anyway, the new page addressed Panel Mount Fuse Holders. Much of the text is a copy from another page, so until I update the listing it will never do well.

I also added another page which contain zero text; Panel Mount Components. Not sure why I added this page, but it is a new page ~ it will be one of those pages that never gets 365 views a year, I already have to many of those.

As with the other new additions, the new page address have been added to the html sitemap. Although they will not be added to the xml sitemap used by the search engines, as I only up-load a new xml sitemap every 3 months or so. But Google should be able to find the new pages regardless.

I still have a number of pic files I want to add to the site, so the next new page address will relate to one of those graphic files I have.

Chassis Mount Fuseholders

2010-03-28T13:15:00.000-04:00

Added a few new pages to Google-sites today to hold some graphics of; Panelmount Fuse Holders, Extractor style Fuse Holders, and a different view of a Panel-Mount fuse holder.

Now I don't normally add a blog posting for new pages to google-sites, but I had added a few new engineering pages to interface-bus and listed them within one blog posting. Not so bad but I use the Blog Archive on the left of the page to count the number of new pages. So the count is off when I add more than one page to a posting. Any how I'm using this posting to address pages on another site to make up for a lack of counting on the main site.

There are a number of pages related to Fuses on the main site, those graphics were a bit to large to add. So;
Fuse Vendors.
DC Operation of Fuses.
Fuse Holder Manufacturers.
Fuse Holders in Chassis Design.
Fuse Derating Recommendations.
Fusible Resistors.
Fuse Definition.

There my even be a few more pages related to fuses, but these have the highest ratings in a site-search. Oh the newest of the pages, Fuse Blocks, is doing the worst with only 13 page views this year. The next worst is the page relating to panel mount fuses used in chassis design.

Capacitor Characteristics

2010-03-22T12:44:00.000-04:00

A new page providing a graph of Altitude vs Capacitor Operating voltage was added. Of course it shows the capacitor case sizes which kind of also define the operating voltage. A small amount of text was also added to support the chart, but it's not much additional data yet.

Another new page was added to address Capacitor Insertion Loss. The Insertion Loss page is linked off the capacitor dictionary page starting with the Impedance Definition. This page has even less text than the other new page, but this always changes over time. The interesting thing is that the site analytics does not even show any page views yet, and I generated this page three days ago.

I also added both capacitor pages to the engineering site-map, keeping that page up to date. The site map lists all the pages contained on the Engineering Web-Site. I also found a few duplicate entries in the site map, so those got deleted, and I also added a bit of supporting text to some of the page listings.

So it appears that the capacitor dictionary section contains 19 pages, with some number of supporting pages. Of course there is also a number of pages that discuss characteristics of capacitors, sizes, MIL Spec, tolerance and so on.

555 Circuit Diagrams

2010-03-21T23:31:00.000-04:00

Yet another 555 schematic was added yesterday. Another Astable Multivibrator 555 circuit, linked off the main 555 Timer Introduction page. This one uses to different circuit paths two charge and discharge the timing capacitor.

I've been calling the listing a Individual Pulse Width Adjustment circuit, but maybe a High-Low Pulse Width Adjustment circuit would be better. At any rate it's a variation of an Astable 555 configuration, but with each of these circuit additions it has more and more circuit elements.

I just generated this schematic graphic, but I think I have one other, so I may yet start another related page address ~ about another 555 circuit.

The next post will be about Capacitor stuff, because I added two other pages the other day but have yet to blog about them.

Definition of Capacitor Terms

2010-03-19T01:40:00.000-04:00

A few new pages have been added to the dictionary of Capacitor terms. The first new page is the Definition of Insulation Resistance, which is linked off the page starting with the Definition of Impedance ['I' to 'L' terms].

While the second new page covers the Definition of Failure Rate, which is linked off the page that did start with the Definition of Farad ['F' terms]. In addition a link to the Capacitor Failure Rate definition was also placed on the page covering How to Derate a Capacitor.

A number of pages in that section were also updated to include both pages in the 'D' portion; Definition of DC Leakage and Definition of Dielectric. Also the Definition of ESR.

I also added the links from the new pages to the HTML Sitemap, to keep that up to date. The sitemap was just updated yesterday to include all the page additions over the last few months. Of course the sitemap lists all the pages contain in the Engineering Website.

I should be adding a few other sub pages to the Capacitor Dictionary in a few days. Like these pages additions today, they should be a page to hold the graphic of some type of capacitor characteristic.

555 Timer Operation

2010-03-15T11:45:00.000-04:00

Following the last post concerning the 555 Timer IC circuits, I added a new page to cover the functional operation of the 555 Timer. This page is written a bit different then the previous pages and tries to explain how the 555 IC functions. Although it does use the circuit setup of a Monostable Multivibrator to explain how a 555 functions, the page is written from a different perspective then the existing 555 Monostable listing.

It does use some of the same text as the Monostable 555 circuit, so I still need to re-read it to fix the text flow; but I did up-load the page today regardless. A few of the same 555 graphic files are reused as well, in addition to a new 555 schematic picture. I have two more 555 circuit graphics, so I plan to generate two more pages today, and I'll be sure to update the page as I add those new links.

At first I was going to have the new page act as a top level topic for the 555, it turned out that the current 555 circuit pages were only listed in passing. Currently the only page listing that references how a 555 functions is the page covering Functional IC Schematics [Internal IC Schematics]. Or not, I just added the link to the other three 555 circuit pages.

Now I've been going to design reviews for 25 years and don't recall ever seeing a 555 IC in any review. That's not to say there any thing wrong with the 555, but it does deserve a mention. So I may generate a page to cover that opinion, regardless of the fact that 100,000's are sold each year. The 555 functional page is already to long, so it's a new topic anyway and gets a new page.

Graphic; IC Multivibrator Block Diagram.

555 Timer IC Circuits

2010-03-12T21:57:00.000-05:00

Added three new pages covering 555 Timer circuits. There's already so much info about the 555 on the web, but I'd been wanting to add the 555 data for awhile now. I don't expect much traffic to the pages because of the other web pages but it still my help some one who is already on the site looking for related information.

Now what I did is start one page and then copy that incomplete page into two other pages. That way as I begin to write the pages most of the text does not turn out to be identical. However that leads to copy-paste errors. But the pages start with the correct back ground data. I think I have corrected most of the typo errors, but I'll get the rest tomorrow.

Anyway I added a page that covers a 555 Monostable Multivibrator circuit, which include a schematic, timing equations and a description. The same holds for the page covering the 555 Astable Multivibrator circuit which was added. Then off the Astable page I linked in a page for a 50% Duty Cycle 555 Multivibrator. The 50% duty cycle page may still have typo's after being generated from the Astable page, but I'll fix them. No one should really be able to find these pages yet anyway, so they should be alright for another 12 hours.

Oh all of the pages appear as if they reside in the Engineering Dictionary section. Linked from the definitions of either Astable Multivibrator, or Monostable Multivibrator definitions. Looks like they are also linked from the Timer definition too. I also already had a page covering a 4098 Monostable Multivibrator so I went ahead and placed a link to the 555 Monostable Multivibrator circuit. Other then that I don't see any other pages I could use to link to the 555 schematics, although I would like a few more. It is what it is, more links may grow over time. Maybe I'll generate a top-level 555 circuits page if more schematics get generated.

Graphic: Internal Block Diagram of a 555 Timer IC, 8-pin circuit package.

Passive Filter Definition

2010-03-03T20:16:00.000-05:00

Much of the data on Passive Filters has been consolidated onto one page, as Passive Filter Definitions. Unlike most new pages the filter page already has a large number of cross-links coming in. As much of the filter data already resided on the site, but under individual filter definitions. The original definitions relating to passive filters remain, but are now also all listed on one page [for now].

So these filter terms also come with a number of graphics, but they were also being used on the site already. A number of new terms have been added for filter types, but most are a different name for a filter already listed. Of course it wouldn't be a very good dictionary page if it didn't list all possible terms.

I may update the passive filter listing again this week, but I think I may also add a page for active filters next week. I hope in the up coming weeks the filter page will be indexed and come up first in an on-site search, instead of many of the other page with only a single filter listing.

Off topic comment, although the site visits are up 20% [pageviews blog posting], hits to the home page of interfacebus are down 9%. However many individual pages show a decline over last year, but I would assume many more show an increase otherwise the site would not be up 20 percent.

Key words; Passive Filter, LC, Capacitor, Inductor, Low pass, High pass.
Graphic pic file; A Common Mode Choke Inductor, through-hole.

Switching Regulator ICs

2010-03-02T12:53:00.000-05:00

I started a new page to cover Switching Regulator ICs. I already have a few new graphics and some definitions in addition to text about switching regulators.

The new page is linked off one of the Regulator Manufacturers page and the Dictionary page covering the Definition of Switching Regulators.

So far I only have two picture files, but look at my hard drive later for another pic file.

As I get the page on switching regulators worked up, maybe by the end of the week, I may add a page to cover linear regulators. I may be able to come up with a few gifs relating to linear regulators. Oh, this new page is not about power supplies, unless you consider a switching regulator IC a power supply.

But one new page was added, with two new gif files. There have also been several other pic files loaded over the last week, just not to new pages.

Communication Handshaking

2010-02-18T19:05:00.000-05:00

A few days ago I added a page to cover the Definition of Handshaking. The page is an addition to the current definition of a Hand-Shake that was already listed. It appears to be a pretty good start at addressing the protocol on how two devices pass data.

These days handshaking doesn't occur that often, most buses operate a lot faster using a clock. But for what ever reason I enhanced the definition. I'll finish up over the week, with more text and a few more examples.

Google indicates only one page view in the last few days, which would be from me? I also don't see the page come up in a Google search, but I'll check again a few hours after I post this.

CMOS Monostable Multivibrator

2010-02-15T22:18:00.000-05:00

I added a new page to show the functional schematic of a CMOS 4098 IC, a Monostable Multivibrator. The page is linked off the page covering IC Functional Schematics. That section currently has 25 pages of functional IC schematics.

A related page covers Transistor Multivibrator Circuits. All the pages are linked off the Engineering Dictionary, for what ever reason.

I also updated the MIL-STD-1553 page too, in addition to many other pages.

Graphic; C5 Galaxy Transport Aircraft, in flight. USAF photo.

Universal Flash Storage card

2010-02-01T16:11:00.000-05:00

The Universal Flash Storage card [UFS] is due to be released in the 4th quarter of 2010. The Universal Flash Storage card would be the 'next generation' in Flash Card. I haven't found to much data on the interface yet, if any. Much of the search results return articles from 2007 when the interface standard was first announced. Other than that I found that the transfer rate would be 3Gbps per lane, which tells me it's a PCIe type of interface with multiple serial lanes. So the new page is blank, that's normal. I'll keep looking for some data, the draft specification should be out on the web......

I would guess that if the standard doesn't come out until the end of this year, I wouldn't expect any Flash cards to appear before mid 2011. However there's always a chance that a company is all ready working on a product, under the assumption that only minor changes will occur to the specification at this point.

Now this is not a computer standard. The specification is really geared to storage applications on a camera or cell phone. But you would still find the interface on a PC as a slot in a Card Reader, or generic flash card reader.

Any way I get to generate a new page, 11 so far this year. I just hope I can find some information on the interface before Google reads that new page and finds it blank.......

Here is a portion of one of those articles from 2007 indicating that Universal Flash Storage could replace the many different flash formats on the market now [which they list]; ".. CompactFlash I, CompactFlash II, Memory Stick, Memory Stick Duo, Memory Stick Micro M2, Multimedia Card, Reduced Size Multimedia Card, MMCmicro Card, Secure Digital Card, miniSD Card, microSD Card, PC Card, xD-Picture Card, Intelligent Stick, Serial Flash Module, µ card, NT Card, and SmartMedia card .." There does seem to be a few competing formats.

Press-on Connector Covers

2010-01-20T22:06:00.000-05:00

I had a few yet to be used connector cover graphics so I added a new page to hold them.
The new page is called Press-on Connector Covers. The original page covered all styles of Protective Dust Covers. Both pages are part of the section on How to design Equipment Chassis.
This will be one of those page that will never see many page views. Although the page does not have a lot of text, the text it does have is a copy of the original page.

Graphic; Rear Panel Circular Mil connectors.

Wire size and Resistance

2010-01-18T10:26:00.000-05:00

I started a new page yesterday in regards to Wire Gauge vs Resistance.
As I get started on it the page my offer a faster alternative to deciphering the larger Copper Wire Gauge table.

Other then that I don't have much to say. I'll keep working on it......

Via Stubs

2010-01-17T07:12:00.000-05:00

Started a new page to cover Via Stubs in Printed Circuit Boards [PCB]. The page is linked off the definition of Via Stub, as a read more kind of thing.

A Via stub is a via that runs past the layer a trace is on. For example a trace on the layer 3 needs to connect to a trace on layer five but the via runs from the top layer to the bottom layer, the stub is the portion of the via that extends past layer 5 running to the bottom layer. A via stub is the same thing as a transmission line stub.

A related page covers How to Terminate a Trace.

Anyway, it's a start to cover the topic, I'll keep working on it for another few hours.
Graphic; Plated Through Hole via in a 6 layer Printed Wiring Board.

Definition of Printed Wiring Board Terms

2010-01-16T09:52:00.000-05:00

I went ahead and divided up one of the last pages of PWB Terms that was just too long. The new page covers PCB Terms from 'Gr' to 'O'. While the original page now covers terms 'A' to 'Ge' [listed first].
So the section also covers PWB Definitions 'P' to 'R', and 'S' terms starting with Secondary Side, and 'T' to 'Z' terms starting with Tented Via. There is also a side page that covers PWB Classifications, which has received almost no page views.
All the pages are now pointing to the new page addition, but the new page still needs a little work with the side bar which is a bit to long. From the counter stats it appears I started this 6 page section on PWB definitions on July 25th, and have slowing been adding new terms and PCB pics. However; there appears to be many days the section either receives no visits or just a few page views.

I should be adding another page maybe tonight covering High speed vias. Maybe I should write it before I pick a name.

Capacitor Networks

2010-01-15T17:22:00.001-05:00

I added a new page the other day on Capacitor Networks, or capacitor arrays and forgot to blog about it. The new page is linked off the Capacitor Dictionary, or Capacitor Array Definition.

The page shows three different Single In-Line Packages, two capacitor networks and one capacitor array, with standard capacitor values. A related page holds the definition of Capacitor Network.

Which for some reason does not have a page rank, not sure why. Looks like this section has 15 different pages of capacitor terms.

Comment; Ya know there is a bad side to capacitor arrays in a single package, like a SIP. Normally you want the capacitor placed as close to some component as possible. Placement becomes a bit hard once all the individual devices are placed or hard-wired within the same component. You can get one capacitor near the area you want it but the others are wired as they reside in the SIP package.

Resistor Networks

2010-01-12T09:49:00.000-05:00

Just added a new page to cover 6-pin LCC Resistor Networks. Yet another page showing a schematic and package style of a resistor network. Currently the page is linked off the 16-pin LCC Resistor Network page.
The new page is a Dual-row LCC package, while the current page is a Quad LCC package. However there is a page that covers a Dual-row 16-pin DLCC Resistor Network, but with no new link yet.
The Resistor Dictionary page the covers the term; Resistor Network Definition.

Looks like the page doing the worst is 8-pin SIP Resistor Network (non-standard connections). With a few page views and no page rank.
I may be able to add the link for the new page to the other related pages in this section.
Graphic; Dual Row Resistor Package.

Panel Mount Resistors

2010-01-11T22:09:00.000-05:00

Looks like the small section relating to Resistor Definitions contains about 15 pages now. Really a few more pages, but using different page addresses so I don't see them in my Analytics filter just now. The newest page is linked off the definition of Panel Mount Resistor, as Panel Mount Adjustment Resistors.

The thing I just noticed from the page view data is that the last new page added a few weeks ago on
Resistor Encapsulation has received no page views; added off the page, Damping Resistor.

So what I did was add a short definition of a panel mount resistor, and then added more data and some graphics on a new page; the difference between a paper dictionary and an HTML based dictionary of terms.

I did want to mention that among all the other pages relating to resistors, a number of pages were added that cover Resistor Networks, but they were added under a different section. So there are more than 15 pages in this section, I'm just not counting them here.

SEO hint; it took 7 months before this section received more than 100 page views in a month [from March 1 2008].

Graphic; Metal Shell, Panel Mount, Potentiometer.

RFI Filters for AC Power

2010-01-09T10:20:00.000-05:00

There's a small section of pages on the web-site covering Equipment Chassis Design. Maybe a guideline on writing a chassis specification or really a ton of recommendations on what to consider when designing a chassis. That index page lists all the topics so the section of interest can be selected with out going page-to-page.

As a sub-topic of AC power modules, a new page was added to address embedded Power Line Filtering.The page has a few words, but not much guidance yet, but I really wrote it late last night. Wow looks like this is page 56 in that section...

Worst page with only about a dozen hits last year; Water Alarm Units. Maybe because it only contains one sentence of text......

Graphic; Open-Source Power Supply picture.

Seven Segment Driver

2010-01-08T20:04:00.000-05:00

Following last months additions of Functional IC Schematics. I added a new function showing the internal gate schematic of a BCD to 7-Segment Decoder Driver. The page is also linked of the page covering a few LED Terms. It seems like I had already added a seven segment decoder page but I couldn't find it, maybe I just wanted to add it and never did.

Companies that produce LEDs, and Display Module Manufacturers.

So second new page addition for the new year, and this is blog posting 193.
Page visits are back up to 9,000 per day, and I hope next week will bring them back to their normal 9,500 a-day.

Panel Mount LED Graphics

2010-01-07T13:44:00.000-05:00

Like so many pages before, I added a new page to hold a large graphic or pic file.
The new page covers Panel Mount LEDs. Because I already had a page covering LED Terms, it's linked off that page [added Nov. 2007].

Next Time I get to it I'll add some more data, and another graphic if I have one. Of course you could also call a panel mount LED a bulk-head mount or chassis mount LED.

The page relating to LEDs with the lowest page views in 2009 was Edison Base LED Lamp Definitions. Which makes sense, how many people know that the base of a normal light bulb is called an Edison Screw Base. Which also reminds me of the current issue with those LED Traffic Lights. Which happen to use Super Bright LED Components [added in Jan 2008].

When I first saw traffic lights using LEDs and not incandescent bulbs I looked it up on the internet; ending with a blog posting back in 2007 [Super Bright LEDs]. I even provided power consumption data for LED lights [13 watts] and incandescent lights [135 watts]. Well guess what, those LED based traffic lights don't generate enough heat to melt the snow that lands on the glass plate protecting the LEDs. So in the northern states those LED traffic lights just fill with snow until the lights are no longer visible. Opps!

Anyway first new page addition of the year.
Graphic; Panel Mount Green Light Emitting Diode.

Headers

2009-12-31T22:45:00.000-05:00

So I did end up generating another new page today, why not. The page covers PWB headers, or maybe the start to the definition of PWB headers. Any way it was generated to hold a few graphics of board headers, which is why it received it's own page. Like many new posts here, this new page has little or no text but I'll add it in a few days. The only link so far is from the Header Definition page.

A few other dictionary pages that have no hits;
Residual Current Device.
COTS Definition.
Balun Definition.
Pulse Shape Definition.

And so on, just a few page links wit no page rank and no page visits this year.
err last post of the year.........

Resistor Definitions

2009-12-30T09:07:00.000-05:00

Off one of the Resistor Dictionary pages; Damping Resistor. A new page was added to cover the term Encapsulation of a Resistor. It ended up on its own page just because the size of the graphic.

At this point there are a number of pages that cover different resistor topics. Here are a few with the lowest page views this year [should be all new page additions]:

8-pin SIP Resistor Networks [un-common].
8-pin SIP Resistor Networks [also un-common].
I've never seen either of these resistor configuration in those SIP packages, but that doesn't mean some one may need them one day.

20-pin LCC Resistor Network Schematics.
SIP Dual Termination Resistor Networks.

Those four pages were some what new, here's a few older pages with no page rank.
MIL-R-39015 Resistor Derating. [Wire-Wound]
MIL-R-83401 Resistor Network Derating.
MIL-R-55182 Resistor Derator Curve.
There's a few more than that, but I'm not really sure why they do not have a page rank.
Looks like the pages have a number of internal links from other pages about Resistor, but no external links. However I just checked they are listed in the site map, but that sitemap may be to large a file for Google to read [they like 100 links or less a page].
There are a few other resistor graphics I have but I don't think I'll get them in by the end of the year. Looks like there's around 50 pages that relate to resistor issues.
Not sure why but the Current Sense Resistors page didn't show very high in a search.
Graphic 16 pin Gull-Wing Surface Mount Package [used with resistor networks].

Fuse Block Holder

2009-12-29T14:08:00.000-05:00

Added a new page to hold a large graphic of a Fuse Block. The page is still mostly a copy of the Panel Mount Fuse Holder page. And also linked off the Manufacturers of Fuse Holders.

Other related pages include;
Fuse Manufacturers. [Fuse Vendors]
How to Derate a Fuse.
DC Operation of Fuses.
Circuit Breaker Manufacturers. [CB Vendors]

Looks like the Fuse derating page was added back in May [Rackmount Computers] and the page on DC Fuse operation was added in April [Maximum Fuse Voltages].
I should be able to update the Fuse Block page some time today.
The data on panel mount fuse holders needs to be removed. A Fuse Block is used inside a chassis while the Panel Mount fuse is located on the chassis wall.
Graphic; Panel Mount Fuse Holder.

Transistor Array Packages

2009-12-28T10:35:00.000-05:00

I added a new page showing a few different types of Transistor Arrays. It's linked off the dictionary page for Array.

Here are a few related pages which only received a few page views this year:
How to derate a 2N3967 transistor.
How to derate a 2N2432 transistor.
How to derate a 2N2604 Transistor.
2N6758 Field Effect Transistor derating.
TO-66 Transistor Package.
Device Under Test definition.
In fact many of the pages that received less that a few dozen hits over the entire year relate to Transistor Derating. But it's hard to make a page on a part number, try searching for a part number and you get hundreds of computer generated pages with rows of part numbers.

TVS Arrays

2009-12-25T15:51:00.001-05:00

Back in Jan of this year [Diode Arrays] I added a two pages covering DIP Diode Arrays and Flat Pack Diode Arrays. Today a page was added covering TVS Arrays in a DIP package. I think I show two different packages of TVS arrays.

If the internet ever comes back on-line I may be able to get another page updated. Google has been up and down sense last night. I've been trying to make this posting sense last night too.

So far this year 4,028,610 pageviews for interfacebus.

Graphic; 20 pin DIP package.

Tee Connector Diagrams

2009-12-23T11:45:00.000-05:00

Off the main dictionary page under Tee Connector, I added a new page to cover a few Tee Connector Graphics. The page only holds the picture files, there is little or no text. I also noted that the main page has no page rank, so I expect few page views for the new 'T' Connector page.

I also added a number of links to other related definitions;
Definition of BNC Connector.
Definition of SMA Connector.
Dummy Load Definition.

The new page shows three coax connectors; a BNC Tee and two TNC Tee connectors.
Reference; Banana Jack Definition. Coax Definition.
Related; Chassis Connector Selection,

Graphic; BNC to Banana Jack connector picture.

Surface-mount Trimmer Resistor Packages

2009-12-23T00:32:00.000-05:00

To support the page on Through-hole Trimmer Packages, I added a new page to cover Surface-Mount Trimmer Packages.
Both pages use the links to Resistor Terms at the top of the page; As in these definitions:
Adjustable Resistor.
Lead-Screw Resistor.
Non-Wire Wound Resistor.
Potentiometer.
Reostat.
Trimmer Resistor.
Variable Resistor.
The page covering companies that Manufacturer Potentiometers works off the link. There also also links to Derating Potentiometers, and Wire-Wound Potentimeter Derating. There are dozens of other pages relating to resistors and Trimmers.
A Trimmer is a variable resistor that is produce that only supports a full adjustments, a trimmer is not made to handle continuous adjustments or changes. Each of those two pages show four or five different examples of package styles.

Graphic; Variable Resistor, Wire-Wound Derating Curve [MIL-R-39015].

Feed-Through Capacitors

2009-12-18T18:54:00.000-05:00

Its been a week or two with out adding any new pages, so I made time.
The new page covers Feed-Through Capacitors or Feed-Through filters, depending on who you talk to.
The page started as a copy of this page Capacitor Terms, or at least a starting place. And I already see that I didn't add that pages link back on the page..
I also added a link off the RFI Shielding page.

Types of Resistor Trimmer Packages

2009-12-08T19:47:00.000-05:00

To complement the page covering Potentiometer manufacturers, a link was added to cover Trimmer Packages. So far it just has a few graphics of Trim Pots, through-hole packages. The page is also linked off the Trimmer Definition page. Reference Potentiometer Definition, or here; Potentiometer. Looks like there is a small one for Variable Resistor.

I'll add another page to cover a few surface mount packages soon.

Looks like there's a page for Potentiometer derating, but not one for how to derate a trimmer.

Graphic; 4mm square surface mount gull wing trimmer.

IC Encoders and Converters

2009-12-07T21:31:00.000-05:00

Just like the last few page additions, these new links were added to the Functional Schematics page.
The first page covers an Excess-3 Code to Decimal Decoder. I'm a bit unsure what the difference is between an Encoder or Decoder. Couldn't any Encoder be considered a Decoder, depending on if the input or output is being referenced?

Anyway the second addition was for a variation of the same thing; an Excess-3 Gray code to Decimal Decoder.

I also added a link from the 'Ex' Definitions page. I may also add a link to the Definition of Encoders page. Looks like this page is missing a Decoder Definition.

It appears there are now 23 pages in this new section of IC functional diagrams.

Integrated Circuit Functional Diagrams

2009-12-06T21:27:00.000-05:00

Added yet more pages today on the topic of functional schematics. These three new pages all cover AND-OR Invert gates. The first is a Dual 2-input AND-OR gate. The next is a Quad 2-Input AND-OR gate. The final is 2-Wide Dual 2-Input AND-OR Invert Expander gate. ~ or something to that effect. Anyway I don't expect any incoming hits, but all the pages are crossed linked. Also they are all linked of the IC Functions page.

I think I also added a page on DIP Switches, or maybe it was last night.

It's not all about three new pages that will see little or no visits, 23 other pages were updated today.

The graphic is a AND-OR Carry Function from a counter.

Who makes Analog Switches

2009-12-05T15:42:00.000-05:00

So in support of the page covering Analog Switch vendors; another new page was added showing an Analog Switch Functional schematic. This new one is a double position, while the previous page was a Single Throw Analog Switch.

Not much to either of those pages but the pin out information for a 14-pin DIP package. But it's another data page in support, so the addition doesn't hurt.
Graphic; Dual Function Single Position Double Throw Analog Switch.

Dual Leadless Chip Carrier Resistor Array

2009-12-03T10:08:00.000-05:00

Yet another page was added to the group of resistor packages; this one is in a 16-pin DLCC package; linked off the 16-pin LLCC package.

Graphic; Resistor Array xN package.

Non-Standard Resistor Networks

2009-11-30T21:09:00.000-05:00

Following yesterdays posting for a non standard SIP configuration; 6-pin SIP nonstandard Network, I added two new pages. I added them just to add the schematics, because I really don't know what application they might be used for ~ but that doesn't mean I shouldn't have them on interfacebus. At the same time I updated many of those pages related to resistor PACs; 20-pin LCC Resistor Network, and the 16-pin LCC Resistor Networks and others.

So any way I added two new pages both showing non-standard resistor pin outs in an 8-pin Single Inline Package:
Non-Standard Resistor Networks.
Uncommon Resistor Networks.
Guess I'm getting to the point I need to add an upper level page to link to all these new related additions.

Of course it's not all about adding new pages; this month the site received over 80 new graphics, on at least that many pages. In addition; my computer indicates over 500 pages were updated, to some degree. However many page up-dates may have been an HTML update being made to a number of pages.
It would seem that over 30 new pages were added this month, out of that 500 page update.

So 500 page updates, of which 30 were new pages, with some 80 new pic files. Of course this blog normally only indicates new page additions and not new pick files or updates.

Graphic; 8 pin SIP Resistor Network.

SIP Resistor Networks

2009-11-29T15:16:00.000-05:00

To follow yesterdays posting on Resistor Networks, a new page(s) was added to cover SIP Resistor Networks. Same schematics as before but now the pin outs match either a;
6-pin SIP Resistor Network,
8-pin SIP Resistor Network,
10-pin SIP Resistor Network.
This time the components are divided by schematic and not package. So, for example, the bused resistor network is shown on one page, with pinouts for each of the SIP layouts;
SIP Bused Resistor Network. [Common Tie point]
SIP Isolated Resistor Network. [Individual Components]
SIP Dual Termination Resistor Network. [Thevenin]
Looks like there are two general styles of packaging. A molded package and a conformal coated version. The page on SIP Packages shows both package styles.

I also just added a few other pages; one for Non-standard resistors in a 6-pin SIP, and one for a 14-pin DIP Resistor Network. They were all uploaded about an hour ago, but I have to many 'in-work' pages so I'll go ahead and stop for now. I may go ahead and update them again, but will not add any other related pages today. Five new pages works......

Graphic; 8 pin through-hole Single In-line Package [SIP] used with Resistor Networks.

What are the different types of Resistor Networks

2009-11-28T20:23:00.001-05:00

Had a page out on interfacebus showing a few different schematic diagrams of both Resistor Array and Resistor Networks in a 16 pin Dual In-line Package [DIP]. The page also linked to RC Networks in a 16-pin DIP, and a page which showed the Passive DIP components. Also have a page covering Derating Resistor Networks.

Anyway I added a new page to cover Resistor Networks in a 20-pin Leadless Chip Carrier [LLCC], or 20-pin LLCC Resistor Networks. I then added one to cover 16-pin LLCC Resistor Networks. I think most of the text is all the same on each of the pages. All the schematics are the same, except for the pin out and the packages so why wouldn't the text be the same.

I just noticed that the dual-resistor termination package in a 16-pin LLCC case only has seven termination resistors, what bus uses just 7 bits of data? Same thing with the common-pin package which only has 15 resistors.

So now there's a page for 16-pin DIPs, a 16-pin LCC and a 20-pin LCC package each with three different styles of resistor interconnections.

Design hint. Resistor Networks are great because they save a lot of board space, but there are problems with these components.
First noise is easily passed from one resistor to the next because they are all in the same package.
Secondly, one resistor [in the package] my be located in the correct spot on the PWB, but in many cases all other traces need to be routed out of their way to reach the resistor package. Individual resistor packages can be placed in the exact location required, resistor networks can not. This may not matter in low speed systems but in high speed networks trace distance does matter.

Graphic; Resistor Array, 16-pin Lead-Less Chip Carrier, 8-resistors, no common connection.

Component Derating Guidelines

2009-11-27T20:32:00.000-05:00

In support of the section on Transistor Derarting, a page was added to explain how to Interpret the derating Curves. Many of the pages already had some text regarding reading the graph, but why keep adding more text to each page if it's the same over and over. The 'How-to' page uses a derating graph from a 2N2904 Transistor, in a TO-39 metal Can.

It was just random chance that I added a picture of a 2N3637 SOA in this posting. I already had a page covering that topic out on Google Sites; Maximum Safe Operating Area.
Normally I don't post new pages added to Google Sites, but I did add two pages today [no text yet]. The internal Construction of a Capacitor, and the internal Construction of a Resistor.

Any other page changes [to either site] today were just small updates.

Graph; Safe Operating Area [SOA] Power Curve, 2N3637 Transistor.

Functional IC Schematics

2009-11-27T11:53:00.000-05:00

Yet more Functional schematics for different Integrated Circuits [IC] were added last night.
A page was added to include a Shift Register circuit, with component part numbers. Also one to include a Parity Checker or Parity generator circuit, with just a few part numbers. Another page includes Flip Flop gates. This one does not include gates with Output Enable lines, so I may add another page later to include those types of flip flops.
To support the page on Decoder chips, a page was adder for Encoder Chips. But neither page provides IC part numbers, at least for now.

I think I also added a page on Binary Adders. I may have also added a listing of Analog Switch ICs. Might be about it. As normal, I'll add some more data in a few days. Semiconductor manufacturers, and Standard Logic manufacturers.

Graphic: Dual Analog Switch in a Dual In-Line package, with pinout.

IC Schematics

2009-11-26T11:51:00.001-05:00

Even more internal IC schematics were added last night. So far they were all linked off the Multiplexer IC page, but by the end of this posting I'll have added a top level page.

Although I didn't have a circuit diagram for an Analog Switch, I did add one for an Analog Multiplexer IC. One circuit for now, but I my add a few more different configurations of Mux schematics and more data too.

Also added a page for a Clock Buffer. That page only shows one 10-line clock buffer schematic and no information, but I hope to add some part numbers some time today. Some what related to clock buffers, a Data Buffer circuit was added. Just a 16-bit buffer circuit, again with no supporting data.

I new page showing a 4-bit Up/Down Counter was also added. Now the counter page actually has some information attached to it. However that page is still waiting on some part number, but like all these pages I hope to get much of the data input today.

The last page addition was a simple Decode IC circuit.

Ok, well I went ahead and added a top level page to the Logic Design section; IC Functional Circuits.

So in the last few days 10 new pages were added, getting any page views from them is a different matter. These pages will turn into a lot of work while producing no incoming visits like the 2N3418 derating curves. While up-dating that page I noticed that the TO-23 Case page was still sitting at a rank of zero, so I updated it a bit. Same deal with the TO-46 Metal Case.

Graphic; Schmitt Trigger IC, Inverter/Buffer.

Transistor Case Styles

2009-11-25T14:21:00.000-05:00

As part of the section that covers Transistor Cases Styles, a new page was added to show a TO-66 package. Except for the graphic, the page is a direct copy of the TO-204 package.

Although this graphic shows a DIP package, only metal cans are shown on the page. The Dual In-Line packages would only serve to show the device pin out, the package sizes are already well known.
The over-all topic is IC Package Definitions.

In most instances these pages just serve to hold a picture of the component package, not much text on any of the pages.

Unrelated topic; The terms Null, and D-Flip Flop, and Debug were added. Just a few of the many upgrades occurring over the last few days.

Graphic; Transistor Array in a Dual In-Line package [DIP].

Identity Comparator ICs

2009-11-24T17:43:00.000-05:00

I spent much of my available time just making some standard up-dates to the list of Components Manufacturers. However I made sure I had time to add a new page; on an Identity Comparator Schematic. I don't think I'll be adding the definition to the Electronics Dictionary. But because the Identity Comparator function is almost identical to a Magnitude Comparator, a link was added off that page. Because I had some 'white space' on the Multiplexer IC page I added the link there too.
Seems like I still have one or two more functional IC schematic that I could upload, maybe in the next few days. Oh each of these page also show all the available IC part numbers as well. Digital Semiconductor Devices.

Graphic; Differential Receiver IC. Click for a larger image.

Integrated Circuit Functions

2009-11-23T18:43:00.000-05:00

A new page was added to cover the definition of a Magnitude Comparator IC. The listing was added in support of the new definition of Magnitude Comparator that was added to the dictionary section.

This follows Fridays blog posting on IC Number Conversions when the page BCD to Decimal Converter Circuit was added. Which followed last Wednesdays blog posting on IC Multiplexers, in which the detailed schematic of an IC Multiplexer was added in support of the definition of Multiplexing.

Also in support of the definition of Parity Check, a schematic was added to that definition, although it didn't make it to its own page. However this schematic may also be moved to a new page at a later date.

Although some what unrelated, a CANbus transceiver circuit was added to the CAN Bus listing. Also when the PI-Bus interface was listed the other day, a PI-Bus transceiver schematic was added to that page. When the JTAG Interface page was updated last week, a schematic of a JTAG Scan Device was added as well. Some time around there a Physical Layer Transceiver was added to the SpaceWire listing. All Avionic Buses for some reason, random chance....

Anyway the next new page to interfacebus will either be another functional IC schematic to tag onto this posting or an IC foot-print to follow yesterdays blog posting.

Graphic; Quad, Dual-Input AND gate Integrated Circuit [click for a larger image].

Non standard IC Packages

2009-11-22T17:40:00.000-05:00

Although I did update a number of pages today, I'm back to adding more IC packages.

I started by up-dating the DIP Package page, making a new entry for a Through-hole Dual In-Line package from that listing. I copied the dual in-line listing to make a Surface-mount J-Lead Dual In-Line package. I had another graphic but I'll get to it on Monday, I had to many pages open at once.

Anyway the dual-row DIP was the non-standard part I was referring to, not sure but I think it was a 1553 part.

Much of the updates today centered on updating pages without a page rank that had not be touched in the last 4 months. For example; Antenna Terms, Radar Terms, or Engineering Acronyms. If the page did not require a text update, then I made some embedded site-wide changes that many pages are getting.

Graphic; HMS Ark Royal and USS-Nimitz. Open Source.

Package Types used by Integrated Circuits

2009-11-21T13:56:00.000-05:00

Although a Small Outline IC was already listed on the IC Surface Mount Packages page, the link pointed to the same page, or the graphic at the top of the page. However I did have a link to a Gull Wing IC package. Anyway I added a new page for SOIC packaged ICs. In connection with the SOIC page I also added a page to hold a Plastic Small Outline Package, which I assume is about the same as an SOIC.

Yet another new surface mount package added was a Land Grid Array, or LGA package. After uploading the grapic to the left I went ahead and added a page to hold a Quad Flat Pack IC. At any rate, the main IC Packages page was updated to point to these new additions.

Of course some of these packages are very common and an engineer will not need a page to show a graphic of an IC they use every day. But their addition tends to round out the site regardless of how common the package styles are. So this small section of pages just received four new ICs today, and 2 others yesterday; with the additions of the LCC Package, and Unformed Lead, Leaded Chip Carrier. It appears that the last IC package added was back in August [IC Package Styles] for the TQFP IC.

Introduced a few new items to the GPIB page.

Graphic is a Quad Flat Pack IC, click for a larger view.

Number Conversion ICs

2009-11-20T04:36:00.000-05:00

To support the page covering Gray Code conversion, a new page was linked in for BCD to Decimal conversion. The original Gary Code definition listing was updated at the same time. The BCD page uses the same number conversion table as before because it shows BCD to decimal numbering, but also provides a schematic for a BCD to Decimal circuit. In this case I also added a few generic part number that do the conversion with out the need for AND/OR gates.

Also added two new Surface-Mount IC Packages; a graphic for a Leaded Chip Carrier, and a graphic for an Unformed-Lead Leaded Chip Carrier. I'm not really sure what the acronym is for an LCC with unformed leads. As with a number of other pages, these only serve to hold the graphic. One graphic helps to speed page loading and keep down confusion. I should be adding a few more today, if I don't get side tracked.

Graphic; Dual, Quad Input NAND gate IC package.

Avionics Buses

2009-11-19T13:42:00.000-05:00

I added a new page today to cover the PI-Bus. The PI-Bus was already listed on the site but only in passing because I really didn't have much data. I still haven't added much to the page, but it's more than I had before and a bit much to leave on the Avionics Data Buses page. I also added a new link to PI-Bus off the interface buses page 'P', data had already been listed there.

Even though I only added a few sentences more than the site already listed, it took 3 hours. As I uncovered data that needed to be added to related pages, so several pages were updated just because of the PI-Bus update. Oh and because I always start with a copy of another page to begin a new page; I updated and used the AFDX page to begin with.

Last week a page covering Laser Diode Manufacturers was added, but I never got around to adding the addition here. The search engines have already found that page but I mention it regardless. That page was linked of each of the other four Diode pages.

Graphic; F-22 Raptor, open source. The F-22 uses the PI-Bus.

IC Multiplexers

2009-11-18T11:24:00.000-05:00

I added a new page to cover IC Multiplexers, and a few multiplexer graphics. I also started with a definition of multiplexers and added many of the common part numbers for integrated circuit multiplexers. I'll be adding more part numbers over the next few days. The new page is added off the Multiplexer Dictionary page.

At the same time a few other graphics were added to the site.

On a side issue, I noted that a few of my key words are seeing a decline over the last year;
Can Bus. also Canbus, and USB Interface.

Manufacturers, Bus Definitions and pinouts

2009-11-17T10:52:00.000-05:00

A few new pages have been added over the last few weeks. Today I added a page to cover Manufacturers of Laser Diodes. I also added a link to a number of pages including Diode manufacturers, Zener Diode Manufacturers, and Companies that produce Varactor Diodes. The page only contains three manufacturers, but I'll get it updated in the next few days.

Last night I added a page to cover PS3 connectors, not sure why but it is an electrical interface. Looks like one of the pins may contain an error, but I added a note to indicate that. The new PS3 page is linked off this bus page; Interface Buses, 'P'.

Last week I split up one of the Printed Wiring Board Terms page, but I don't remember which one;
PWB Terms, A - O.
PWB Terms, P - R.
PWB Terms, S.
PWB Terms, T - Z.
Of course many pages have been updated, but only new pages get listed here.

How did the OBD vehicle Interface come about

2009-10-25T16:35:00.000-04:00

I'm not sure why but I added a page to cover the Background of the OBD bus. OBD stands for OnBoard Diagnostics and is used as an in-vehicle debug port. I guess I added it because I was up-dating a few OBD pages and got a little interested in the history.

Although reformatted much of the data is from the EPA's site [EPA sets the standard requirements], with some supporting data from a few state government sites..

The OBD interface makes that 'Service Engine Soon' light to come on in your car, the light that no one knows what it means.

I linked the new OBD page off the OBD Terms page. The main page relating to OBD is the Description of OBD listing.

Graphic; Dash Board Check Engine Light.

Definitions of Printed Wiring Board Terms

2009-10-24T14:09:00.001-04:00

I went ahead and divided up the page covering Printed Wiring Board Definitions because it was getting a bit large. Not that the length of the page was much of an issue, but with all the graphics the download time was starting to get a little slow. The original PCB dictionary page was about 19 pages long, with many pics. Now after the change the page is only down to 18 pages, with all the additions I just added to the page.

So the original page covers PWB terms from 'A' to 'S' and the new page covers PCB Terms 'T' to 'Z'. I also generate a new page covering Types of PWBs, because the definition was some what long. In another few weeks I'll be breaking up the PWB Terms page again, because it still looks to large. Related terms; Glossary of Packaging Terms 'A' to 'B', Dictionary of Packaging Terms 'C' to 'Z'. Integrated Circuit Packaging.

Additional PWB links are located on the Information on Printed Wiring Board page.
Also on PWB Vendors Services.. Data on Conformal Coating.

Graphic; Coined or flattened axial leaded part, attached to a copper land on a PWB.

What are Serial Buses

2009-10-23T16:13:00.001-04:00

Well a serial bus is a bus with a single data line, or a pair of data lines in the case of a differential set. How come PCI express uses a pair of receive lines and a pair of transmit lines, I guess you could say it's still a serial bus but with simultaneous transmit and receive capability. But what about the JTAG and SMbus interfaces that get glued onto the PC expansion bus? Is it still a serial interface. The 1x PCIe bus uses 36 lines, including power and grounds, that's a lot of pins for a serial bus.

Now what about the 16x PCIe interface? PCIe 16x has 16 differential pairs going in each direction [16 Tx and 16 Rx], and it still has the JTAG and SMbus interfaces. That's 164 traces for PCIe once you count all the ground lines. At least some serial buses like CanBus use one net [pair], or a differential pair but it still requires a 9-pin D-sub connector.

How is that different from an 8-bit, 16-bit, 32-bit or 64-bit parallel bus? The PCI bus only uses 188 pins to develop a 64-bit bus, that's only 20 more nets than PCIe and you get a lot more control pins.

So you get your requirement to interface two boards together and your told that one of the boards is I/O constrained, do you walk into a design review and say you serial bus implementation requires 164 nets?

The first digital bus I ever designed to was the GPIB interface, the old byte serial, bit parallel interface. So I really already know what the difference between a serial bus and parallel bus is; A Serial bus transmits a byte sequentially one bit at a time, while a parallel bus sends the entire byte out at once over individual lines. There is no limitation on the number of pins for a serial bus, but I would assume the normal assumption would be less than a dozen nets at most.

The point is a new page was added covering the Serial Wire Debug Interface, one of the true serial buses. Well maybe not, looks like it needs power and ground and resides on a ten pin header. Maybe IC to IC communication on the same PCB only requires just two nets, I'll have to do a bit more research on the topic.

Of course any copper wire parallel bus will be lighter weight than a hydraulic control system. With less lines, a serial bus should be lighter still, requiring less wires than a parallel interface. Better yet a network designed to operate over an Optical fiber would come with the lowest weight penalty.
With the cost of putting metal into space being about $10,000/pound the best design would be the safest, most reliably and the lowest weight. The same is true for any Avionic Bus Design. The Protocol may not set the maximum weight of the bus but an interface's protocol sets the minimum safety requirements of an interface and monitors and adds to a buses reliably.

Graphic; Comparison of different size NASA rockets: Saturn V, Space Shuttle, Ares I, Ares IV, and Ares V.

Patch Panel Manufacturers

2009-10-17T04:30:00.000-04:00

As part of the How to Specify an Equipment Rack, a new page was added that covers Patch Panel Installation. Both topics are linked off the main page relating to Equipment Chassis Design. A few other pages in the section were also updated at the same time.

The patch panel page provides a description and a small list of manufacturers and should enhance both sections on chassis and rack design. A link to the patch panel page is also provided on the Engineering Dictionary page.

Graphic; 19 inch telco patch panel installed in a rack, also showing panel jumpers.

Interest in the PCI Bus is Falling

2009-10-16T00:38:00.000-04:00

I was just updating some of the data relating to the PCI Bus yesterday, really just adding some data. There was no new page added.

The main page relating to the Peripheral Component Interface is the PCI Bus Description. Just a few lines of text were added, the real update occurred on the page containing the PCI pin out,[which does not have a page rank?]. I started to add a better description of the signals, and added a few more notes. There are also two additional pages that were updated, each related to PCI card size; Half Sized PCI Board, and Full Sized PCI Board. I guess the only other page is Manufacturers of PCI Boards, but it wasn't updated.

I noted a steep decline in page visits for any of the pages relating to the PCI Interface, by about 4-to-1 over the last three years. Google had data that goes back to 2004, so I posted their graph for PCI Bus searches instead.
The Graph is a Google Trend for the search term PCI Bus.

Electronic Equipment Cabinet Installation

2009-10-14T18:44:00.000-04:00

Following the last posting covering Equipment Rack Design, a new page has been added to the same section relating to Chassis Installation within an Equipment Rack. The new page follows the topic on Equipment Cabinet Grounding and proceeds the topic covering Manufacturers of Electronic Racks [which leaves the section].

Over the last three years there has been no real increase in pages views for this section. In fact other then the page visits being some what flat, they have really been a bit low this year. The main page to the topic starts at; How to Design an Equipment Chassis, with some topics covering what to avoid too.

Remember if your designing a chassis for ship board use consider Components to Help with Anti-Vibration, or Chassis Self Leveling Products. Of course any of the other topics are relevant also; in addition to the one relating to Military Chassis Specifications.

Photo Credit; US Navy. Ticondergoa class cruiser, Port Royal

Equipment Rack Design

2009-10-09T14:24:00.002-04:00

There's a section of pages out on the web site devoted to the topic of how to design an Equipment chassis. As in Designing an Electronic Equipment Chassis.
Within the section are a number of related topics to chassis design, for example Equipment Rack Issues. Below that, a page was added covering Equipment Rack Rails, which is linked both off the main page and the page it follows; Electronic Equipment Rack Sizes.

Yet another page that was added to hold a graphic, so it may be another month before any real text is added to the page. However when looking over the entire section it seems like a good tutorial on how to design or specify an equipment chassis.
At the very least it provides issues to think about and pitfalls to be avoided, over a span of 52 web pages.

Related Postings covering Chassis Design;

Cable Harness Design Considerations. Aug 16 2009
Equipment Cable Runs. Aug 11 2009
Industrial Rackmount Computers. May 21 2009
Designing an Equipment Chassis. Apr 29 2009
How to Design an Equipment Chassis. Feb 17 2008
Photo Credit; Sun.

What does DUT Mean

2009-10-07T06:27:00.002-04:00

Added a new page to supplement the Definition of Device Under Test. The new page just holds a few graphics of transistor schematics showing Transistor DUT Circuits. In addition to being linked off the main DUT page, a link was also added to the page covering How to Derate a 2N1711 page.

The DUT pages are a subsection of the Dictionary of Engineering Terms. With related pages of Definition of Transistor Terms, and Definition of System Test Acronyms.

There a number of other relating pages my be found on any of the links above.

Who Makes Telecommunication ICs

2009-10-03T14:01:00.000-04:00

I was looking for Telcom connectors the other day, or more correctly some one who produced GigE connectors [GbE]. Specifically I was searching around for an RJ45 style connector. I happened to call up the analytic data and noticed that page views for TeleCom connectors were down a bit over the last few years so I decided it was time to update that page.

Around the same time I remember I had a page covering Telecommunication IC Vendors as well. I then pulled up pageview data for Telecom IC manufacturers and was amazed to find that page-views for telecommunication related ICs had fallen to almost zero a day. Of course I'm in the process of up-dating that page too, maybe fixing is a better word.

I think I see what the problem is, but I don't really want to talk about the competition..... At any rate, I'll have the page updated today at least in part.

This blog is about new page additions.......
Two new pages out on google sites were added primarily to hold large graphic files.
One page covers the Definition of Thermal Impedance.
The other page covers the Definition of Maximum Safe Operating Area.

Of course I linked to them, the page covering Derating a 2N3637 Transistor is linked to the Max SOA page, as the graph relates to a 2N3637 BJT. Also the Transistor Derating Guidelines page links to the Thermal Impedance definition.

The main site received a page relating to PCB Thermal Resistance for FR4 boards vs pad area. The page complements the listing of Printed Circuit Board Terms.

Semiconductor Case Drawings

2009-09-25T17:10:00.000-04:00

Added a few new pages covering transistor package styles.
This series of pages really don't generate any incoming hits, but I already had the data so why not just add the pages. Plus its been awhile with out adding any new pages.

The first covers a TO-18 Transistor package.
The second page covers a TO-92 Transistor package.
A third page covering a TO-204 Transistor.
A final page covering the TO-220 Style Package.

The graphics used on these page were already being used on some other page on the web site. So the only new thing that was added today was four new web pages, but the data was already on the site at a different page. However these new additions do round out the main package style page.

At any rate this posting shows the 3 new pages and provides an external site that links to them, I can't really help that they may never see any visitors.

Relay Derating

2009-09-11T19:49:00.000-04:00

I just notice that the page covering How to Derate a Relay was never listed in the blog when it was added to the web site. Looks like the page was added back in March, or at least that was the day of the first page view.

The page doesn't get that many hits, just a few a-day. I went ahead and added a new link at the top of the page covering Manufacturers of Relays. Then I did the same thing to the page covering Manufacturers of Mechanical Relays.

I also removed two manufacturers links, one looks like it went bad and the other appeared to be a relay distributor. Also added a picture of a relay.

The three pages covering relay manufacturers have dropped 50% over the last three years. Seems odd, as the relay pages come up as number 1 and 2 on a Google search for relay manufacturers....

Sony's DMP Interface

2009-09-09T04:35:00.000-04:00

I added a new page the other day to cover the Digital Media Port [DMP] interface. The bus was developed by Sony and only resides on their gear. The page lists one possible pin out, and I don't know if there may be others. I have no other information on the interface.

Digital Media Port

The page is linked from these two pages;
Engineering Interface Buses, 'D'.
Cable and Backplane Buses.

Because this bus is only being used by Sony I may not be able to find any additional data.

Cable Harness Design Considerations

2009-08-16T10:16:00.000-04:00

As part of the design section on how to design an electronic chassis, a page was added to cover Cable Harnesses. Or additional considerations to account for when you require a cable harness within a chassis.

When to Tie wrap a cable, how often a tie wrap should be used along a length of cable and additional issues not covered on the original Specifying a Cable Assembly page. I will be adding a sub-section on splices to cables on that new page as well.

Other pages that were recently added include;

Equipment Data Runs; covering Possible Data Rates. 8/11/09

Equipment Rack Grounding; covering How to Ground an Equipment Rack. 7/31/09

Industrial Rack Mount Computers; covering

....... Rack Mount Computers. 5/21/09

....... Cable Retracters. 5/21/09

Designing an Equipment Chassis; covering

....... Chassis Wire Selection. 4/29/09

....... Chassis AC Module Selection. 4/29/09

I don't see any other new additions to the chassis design section in this blog. Of course pages get updated all the time. Here are some key phrases;

How do I know where to tie wrap a cable.

How often do I tie wrap a cable.

Can I put splices in a cable harness.

Equipment Cable Runs

2009-08-11T19:25:00.000-04:00

A new page was added to the section on How to Design an Equipment Chassis. The new page covers Cable Data Rates vs. Cable Length. Of course it's a new page that was only added over the week end; but, it does have a nice graph that shows Cable length vs Data Rate.

Now there's not a big calling for cable length data within a 16 inch chassis, but this section does cover rack gear as well. So rack to rack cable length could be a concern. Also the new page will support articles on Cable Assemblies and other pages relating to rack and chassis cable selection. So the page may not be all that relevant to chassis design, but it can't hurt. Plus soon other pages that do relate to cable length will soon be pointing to it, so it should be a nice addition to the web site once some data and text is added to it.

The group of pages that make up the electronic chassis design consists of about 50 pages.
Worst performing pages; looks like a tie between two pages;
Rack Mounted Temperature Alarm Units.
Rack Mounted Air Flow Alarm Units.

IC Package Styles

2009-08-02T18:41:00.000-04:00

A new page was added to cover the Thin Quad Flat Pack IC Package; TQFP Style.

It is one of a number of pages covering IC package styles. The two main sections cover Surface Mount packages, and Through-Hole packages.

Many of the individual pages relating to Integrated Circuit [IC] packages were also up-dated or optimized. A number of pages did not have captions for the graphics or HTML 'alt' tags to indicate what the graphic or picture related too.

Related pages; Diode Packages, Transistor Packages.

Equipment Rack Grounding

2009-07-31T11:08:00.000-04:00

As part of the section on How to design an equipment chassis, a page covering Rack grounding has been added. The new rack page will help to support section 7 which covers Equipment Rack Issues, as well as section 6 which covers Grounding Issues.

All pages support the topic covering Chassis Vendors. The last time a page was added to this section was May 21, with the addition of Rackmount Computers, and Cable Retractors.

I think at this point the information in the section covers the topic pretty well. Not real sure how easy it is to navigate the section, but each page provides a link back to the contents page...

Printed Wiring Board Definitions

2009-07-25T08:22:00.000-04:00

A new page was added to cover Definitions related to PWBs. Most if not all of the terms were already listed within the Engineering Dictionary, but are now combined on one page.

I think the only incoming link is from the Electronic 'P' terms page, but I'll add more soon.
Oh, so this is the first up-load so some off the additions may look different because they come from different pages and of course some common terms may be missing. This page has been in the To-Do box for a few months, so no matter what it has to be a good start.

Up-date; I've added links to the PCB dictionary from the main PWB Information page, PCB External Trace Current Carrying Capacity, and PCB Internal Trace Current Carrying Capacity. A link also resides on the Definition of Minimum Annular Ring page.

Resistor Attenuators

2009-07-18T09:28:00.000-04:00

I added a new page to cover schematics of different styles of Resistor Attenuator Networks. The page should support the section of Resistor Terms and Resistor Attenuator Manufacturers.

Normally these devices will be surface mount components so the common term will be Chip Attenuator. The new page shows schematics for the Pi attenuator, T attenuator, and L attenuator.

HCSL Components

2009-07-16T19:15:00.000-04:00

A new page was added last week to cover HCSL Clock Oscillator Manufacturers. HCSL switching logic is used with PCIe to name just one interface.

The new page is linked off the main Oscillator Manufacturers vendor page. There is also a link of the Engineering Acronyms pages.

Photo credit; army.mil, Rifleman Radio