Added two new pages a few weeks ago relating to VPX boards which is the new style of VME card.
I didn't list them because I was not able to verify the data, but I'll list them now regardless.
I just checked and the new pages have not been found by Google yet, but Google will find the VPX pages today with this posting.
VPX Signal Assignments;
Pinout for the VPX J0 Connector.
Pinout for the VPX J1 / J2 Connector.
Both VPX pin out pages are linked off the VPX Board Description page.
Additional pages related to the VME standard;
VITA 48, REDI Standard.
VPX Board Manufacturers.
VXS Board Manufacturers.
VME Backplane manufacturers.
VME Chassis Manufacturers.
VME Bus Definition.
There are additional pages related to the VME format, not listed here.
Saturday, July 4, 2009
VPX Computer Board Format
Monday, June 22, 2009
Terms used with Resistors
A dictionary of Resistor Terms was started back in 4/08 and consisted of 10 pages [Blog entree; Resistor Definitions] A few months later the 'B/C' page was broken into two separate pages 2/09 [Blog entree; Dictionary of Resistor Terms]. Some time later the 'O' page was added.
Yesterday, yet another page was added by separating the 'F-M' into 'F-L' and 'M' pages. Here are the current pages, listed by the first definition on each page:
Active Resistor. 'A' Terms
Ballast Resistor. 'B' Terms
Carbon Film Resistor. 'C' Terms
Damping Resistor. 'D-E' Terms
Ferrule-terminal Resistor. 'F-L' Terms
Maximum Voltage Rating. 'M' Terms ......... This is the new page that was added
Network. 'N' Terms
Ohm. 'O' Terms
Phenolic Molded Resistor. 'P' Terms
Rated Continuous Working Voltage. 'R' Terms
Semiconductor Resistor. 'S' Terms
Tab Mounted Resistor. 'T' Terms
Variable Resistor. 'V-Z' Terms
There are also a number of side pages detailing Resistor design;
Resistor Tolerance definition.
Resistor Values - Package Sizes.
How to Derate a Resistor.
There are a number of others, but this off-site pages lists many of them: Resistor Products.
Hits to the resistor dictionary really didn't start to pick up until January of this year.
Saturday, June 20, 2009
NATO Interface Bus
A new page was added that covers NATO Advanced Data Storage Interface [NADSI], or STANAG4575. The specification details a board used for removable memory. The electrical interface used Fiber Channel, but one of the possible physical interfaces is a 50-pin D connector. The D-connector must be used for legacy systems, seems a bit odd. Also it uses the out-dated MIL-DTL-24308 series connectors. It seems under normal conditions the interface will be on a MIL-DTL-38999, which makes a little more sense.
Any way for the NATO name, I added a link from the 'N' interface Buses, and for the STANAG name a link was added from the 'S' interface buses page.
Photo credit; Army ".. memorial for three Soldiers from the 252nd Combined Arms Battalion, 30th Heavy Brigade Combat Team ..."
Wednesday, June 10, 2009
Solid State Drive Vendors
Added a new page on Solid State Drive [SSD] manufacturers a few weeks ago. SSD may also stand for Solid State Disk, depending on what page you may check. The page started as a copy of Hard Disk Drive [HDD] manufacturers.
The page still has a few notes relating to HDD vendors, but has many more listings that relate to SSD vendors. There seem to be only two main form factors;
Laptops, at 1.8"
Desktop at 2.5"
They also seem to be supplied with one of two main interface standards;
Serial ATA [SATA], SATA-I, or SATA-II
Parallel ATA [PATA]
These are drop-in replacements to a normal HDD devices, and operate much faster.
The smaller 64GB SSD's don't seem to cost that much any more, at a tad less than $200. However 64GB is almost to small to use as a main hard drive. I purchased a 10,000 rpm hard drive a few years ago as a data drive, so I guess they may function as a non OS drive. I wouldn't attempt to put Windows Vista on a 64GB drive.
I see 80GB and 128GB drives running into the $300 range, still to small to be usable. The larger drives containing 250GB of memory are ranging from $700 to $900, which could be the total cost of a new computer. Maybe by next year the price will come down so most people could purchase one with out any sticker shock.
I found one 8GB PATA device for $100, not really sure why I wouldn't use a USB Flash device at that point.
I also noted that normal desktop PC drives use MLC devices, while server side drives use SLC devices. Definition of MLC.
A related page covers Hybrid Hard Disk Drive [HHD] manufacturers. Hybrid drives have a platter but also contain more flash memory operating as a larger cache. I'll bet these don't stay around much longer than next year once SSD memory prices are reduced.
Thursday, June 4, 2009
When to Dearte a Transistor
Copied another page on how to derate a transistor into two other pages that used the same derating chart.
2N4237 Temperature-Power Derating Curve, duplicated to.
A few other related pages in the section were also updated
Some of these preexisting pages may not have ever been listed out here as new pages, so this may be their first posting. In any case it's yet another external link generated.
There are three different possible guidelines a designer can use when implementing a transistor circuit.
1. The engineer may use a generic guideline using a simple Derating Factor;
Example: Derate 50% up to a maximum junction temperature [Derating Factors].
2. The engineer may use a Linear equation which is more a design recommendation;
Example: Derate Linearly at 12.7mW/ degree C, above 25C [Derating Recommendations].
3. The engineer may use a Temperature-Power Curve which should be treated as a design rule;
Shown on any number of pages, [Derating Rules].
There were two other pages up-dated to hold the links for the page just generated;
Addtional related pages on the web site:
Additional related pages on this blog:
Tuesday, June 2, 2009
Rules for Derating a Transistor
Following yesterdays transistor posting, I've added two more pages relating to how to derate a particular transistor. Like the previous post the new transistor pages are near a copy of a preexisting page, that happened to use the same derating graph.
MIL-PRF-19500/539D:
2N6301 Temperature-Power Derating Curve [NPN BJT].
2N6300 Temperature-Power Derating Curve [NPN BJT].
MIL-PRF-19500/545G:
2N5153 Temperature-Power Derating Curve [PNP BJT].
2N5151 Temperature-Power Derating Curve [PNP BJT].
Three other page up-dates then followed;
Which were updated to hold the links to the new pages. In addition each new page links to it's copy that holds the same MIL Spec and Derating Graph.
Also added a new line item to the Transistor Derating Recommendations page, which only provide Derating Equations with no Derating Curves.
It may of taken over a hour to generate the page up-dates but it was an easy way to generate two new pages and add more page to page links.In addition four other related pages were updated:
MIL-PRF-19500/396K;
MIL-PRF-19500/396K;
So in this derating sections there were 10 page up-dates and 2 new page additions. There were also another dozen unrelated page updates.
Transistor Derating Guide Lines
Added a new page to cover power derating of a 2N3765 transistor. The page is almost a copy of the page for the 2N3764 transistor because they both use the same derating graph. Links have been added to their related transistors covered by the same specifications; 2N3762U4 transistor and 2N3762UA transistor, both surface mount devices. A reference was also added to the page covering PNP transistor curves, and derating transistors.
A few other unrelated pages were also up-dated, including;
All the pages provide a Temperature-Power Derating Curve, and some also provide a derating equation. Use one or the other as a guideline for derating the device.
Related pages;
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