Chassis Mount Power Resistor

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

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..