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www.RomanBlack.com - web Aug 2006

UltraCAD's PCBTemp.EXE
Freeware program to calculate PCB track resistors and track currents, heating etc.

I did NOT make this software!
It is made by UltraCAD at www.ultracad.com

This freeware program can be used to calculate PCB track heating and current carrying capacity. One of the most handy uses is to calculate PCB track resistors based on the track width and length. These are great for zero cost low-ohms resistors to use as current measuring shunts etc.

UPDATE - 10th May 2012

Please note, UltraCAD have contacted me and said this old version of theirs is out of date!

I don't know what is outdated in their old version that I mention here and I don't understand the specifics of the new IPC specs that the calculator is based upon, so all I can offer is a snippet from their email to me;

"That calculator is obsolete. It was based on the old IPC-D-275 which was obsoleted by the new IPC 2152 Spec. UltraCAD has stopped supporting PCBTrace. We request that you take down the link to it. We would be happy to have you post a link to the newer calculator, UCADPCB3 which is available on our web site;" http://www.ultracad.com/calc.htm


  • Track width; "Mil" means "thou" or thousandths of an inch.
  • Copper thickness; most high quality double-sided PCB copper is 2 oz type.
  • Copper thickness; hobby grade single sided is often 1 oz type.

    To calculate a PCB track resistor;
  • Enter Width = 10 (standard PCB fine track)
  • Enter Thickness = 2 (standard PCB copper)
  • Enter Length = 1 inch
  • Click "recalc" (answer is in ohms per inch of track)

    Then check the track does not get too hot;
  • Enter your max Amps
  • Click Temp CHANGE (Solve)
  • Observe temp, check resistance has not risen too much
  • Try to keep track temp change less than 10'C

    Download it

    File removed May 2012.
    (The new calculator is available from UltraCAD's website, please see the top of this page for details).

    - end -

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