Press-on Connector Covers

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.

RFI Filters for AC Power

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.

Patch Panel Manufacturers

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.

Electronic Equipment Cabinet Installation

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

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.

Cable Harness Design Considerations

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

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.

Equipment Rack Grounding

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...

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.

2N4238 Derating Graph.

2N4239 Derating Graph.

A few other related pages in the section were also updated

2N3498 Derating Graph.

2N2906 Derating Graph.

2N3634 Derating Graph.

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;

Guideline to Derating Transistors, and Guideline to Derating NPN BJTs.

Addtional related pages on the web site:

Manufacturers of Transistors.

Transistor Amplifier  Circuits.

Transistor Circuit Schematics.

Transistor Multivibrator Circuit Schematics.

Definition of Transistor Terms.

Additional related pages on this blog:

Rules for Derating a Transistor.

Transistor Derating Guidelines.

Recommendation on how to Derate a Transistor.

Derate a BJT by Temperature.

FET Derating Guidelines.

NPN Transistor Derating Curve.

Power Derating for Transistors.

Industrial Rackmount Computers

As part of the section on how to define an equipment chassis specification, two new pages were added.

The first page covers Industrial Rackmount Computers. The Industrial computers page provides a few design hints and a listing of companies that produce industrial PCs. The original list of industrial PCs had resided on the Manufacturers of PC Chassis page. The PC chassis vendor page now only holds commercial products.

The second new addition covers Cable Carriers or Cable Retractors. A Cable Carrier helps manage cables between the equipment chassis and the chassis rack. Using a cable retractor insures that the cable assembles bends and moves the correct way as a chassis is being moved in and out of a rack. Cable retractors also insure that the cable does not bind on any thing behind the chassis or within the rack. Within a few days the page will also cover Cable Retractor manufacturers.

Also added two more chassis specifications to the chassis standards page. Of course the main page in the section now lists the new page additions. Two new link additions to the section include; Fuse Derating, and Power Supply Standards. Also fixed the link to manufacturers of Anti-Vibration products, which happened to be pointing to the Rack Leveling products page by mistake.

The purpose of the entire section is to show a novice how to design an equipment chassis, or how to write a specification so an OEM could design the chassis. In any case the pages provide many design hints and engineering guidelines as well as some do's and don't s concerning electrical equipment design.

The industrial equipment design section spans 46 pages with links to other relevant topics on the web site. Don't get burned when purchasing an equipment chassis, review the different section that are relevant to the chassis your designing.

The page covering manufacturers of chassis has a link to the top page in this section.

Designing an Equipment Chassis

Two new pages have been added to the section covering How to Design an Electronic Chassis. The section spans about 44 html pages and attempts to cover all the issues when designing an Electronic Equipment Chassis.

The two new pages cover Wire Selection, and AC Power Modules. However; over the same time there have also been a few pages that were up-dated, including; Connector Dust Caps, Slot By-Pass Cards, Chassis Wire Selection, Slot Filler Panels, and a few others.

At any rate, there is now more information in the section that cover more topics in greater detail. There were other pages updated not listed here, but these were the major updates.

The hits to this section are down a bit over the last year, but only by about 50 visits a week, or 200 a month. It could be the reduction in hits is just due to the time of year..... What ever, any way the up-dates will not be seen by Google for several weeks.

The Bounce rate for this section hovers around 60%.

How to Design an Equipment Chassis

I produced a section of pages back in 2005 relating to Electronic Equipment Chassis Design.

The attached pic shows total page hits for that section from the middle of 2006 on, and the top 10 producing pages. Although it says 86 URL's, there really are only 42 pages. Looks like the section get about 50 to 150 page views a week. With about 16,000 page views in 2007.

Any way I'm out up-dating the search bar on those pages and notice [again] that a number of pages have no page rank any longer. I posted a related entry in the main blog "pages losing ranking". Looks like about 10 pages no longer have a page ranking from Google. Here are those page links:
Equipment Racks Shelfs.
Equipment Rack Casters.
Panel Meter Manufacturers.
Equipment Chassis Slot Keying.
Chassis Connector Types.
Elapsed Time Indicates.
Rack Mount Environmental Alarm Manufacturers.
Chassis Cable Assemblies.
Electronic Terms for Equipment Chassis.
Page two of Chassis Terms.

The only thing I can figure is that because these pages get so few page hits, that they lost their page rank. Internal Pages point to them, and via the sitemap, external pages point to them. And now this blog points to them.

These pages help to round out the How-to section, so I don't really mind that they my be getting just a few page views. I would rather have the page there for someone than not have it...