K or C are (almost) identical, just the starting point is different: C starts @ 0 (freezing temperature for distilled water at sea level pressure, i.e., 1 atmosphere), and defines 100 as boiling of same conditions. K is the same as C, but is off-set by 273 (i.e., 0 K is -273 C, so 100 C is 373 K).
What transformation did you use to get those weird numbers? Cheers, N. Shani Ottawa, ON On 10/9/12, McInturff, Gary <[email protected]> wrote: > Thought I knew what I was doing, obviously I don't > I have a device with a thermal resistance ThetaJA (J-P in this > documentation). It's for SMT CHIP LED the specified value is 400C/W. for a > plastic package that seems about right. I am looking at another LED but it > lists ThetaJA as 400K/W. (Kelvin/Watt) Seems pretty good as it would > convert to 126C/W - the lower the better. But then I converted the ThetaJS > (I think its junction - solder point), and that value was 180K/W. When > converted its -93C. Does the change in sign just indicate the direction heat > is flowing? ThetaJA is positive since the heat is leaving the die through > the package, and the ThetaJS is negative because it is heating entering the > die through the solder process? > > > Gary McInturff > Reliability/Compliance Engineer > > > > > > > > > Esterline Interface Technologies > > Featuring > ADVANCED INPUT, MEMTRON, and LRE MEDICAL products > > > > 600 W. Wilbur Avenue > Coeur d'Alene, ID 83815-9496 > Office:208-635-8306 > Cell: 509 868 2279 > Toll Free: 800-444-5923 X 1238 > [email protected]<mailto:[email protected]> > > > www.esterline.com/interfacetechnologies<http://www.esterline.com/advancedinput> > > Technology, Innovation, Performance... > > > > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in > well-used formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://listserv.ieee.org/request/user-guide.html > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
