I invite you to look at UltraCAD's freeware trace/temperature calculator at
our web site.
Go to http://www.ultracad.com
and follow the links to the calculators.

A desciption of the formulas used and their derivation is provided in the
help file.

Doug Brooks





At 06:56 AM 10/27/99 -0700, you wrote:
> Hi, My name is Steve Troie and I have a few questions about the charts that
>I use in IPC-I-00005, to determin how much current a trace can carry
>based apon copper weight.
>
>1- Why does the chart list several tempature ranges?
>   Why not design just design for 10 celsius above ambient only?
>
>2- Do you have the formula that produced these charts?
>   If so, could you send it to me?
>
>   Regards
>
>Steve Troie
>Senior Designer
>Trimble Navigation Limited
>585 Maude Court
>Sunnyvale, CA. 94088-3642
>
>(408) 481-2913 Voice
>(408) 481-8183 Fax
>Email: [log in to unmask]
>
>
.
****************************************************
Doug Brooks, President              [log in to unmask]
UltraCAD Design, Inc.           http://www.ultracad.com