I have a few To220 thick film Vishay resistors that I need the power rating for.
The makings on them are.
48232
A0051
ks24248L1
5R00 .2%
I have looked and couldn't find this resistor but noted some of Vishay's TO220 resistors
are rated for only 15 W where others are rated up to 35 W so I can't just judge from the
TO220 case.
The makings on them are.
48232
A0051
ks24248L1
5R00 .2%
I have looked and couldn't find this resistor but noted some of Vishay's TO220 resistors
are rated for only 15 W where others are rated up to 35 W so I can't just judge from the
TO220 case.
Have you expanded your search engines? I have found stuff using Dogpile that Google did not find.
Probably anything in a to-220 case burning 15W is going to be glowing red hot unless you stick it to something.
Well, the pieces would be glowing red hot. Probably no more than 2-3W is what it could take bare.
Max power ratings are usually for notional 100% heatsinking, ie package exterior held at 25C by whatever it takes. Normally the
spec says "Tcase = 25C" or something like that. Ratings for no heatsinking might have "Tambient = 25C".
This device is intended to be mounted on a heatsink but I need to know the maxium power rating with a Tcase = 25C
is that a personal experience or a good estimate? Once I had an IGBT hanging as 10W load by a runaway accident, and when I touched I moved the pure tin on its back. So, 10W in air in TO-218 (??) 15W should be fine for 30 seconds. 3W should be fine for a day. 1W for a year. It's always about the reliability. The 15W rating (with cooling!) is there to prevent aging, and the resistor will age and drift even at the 15W rating... it an take more, but reliability and stability will be affected. Plus, there is some insulator and that one will crack with high power loads.
PLUS, 15W is 3A already. Which is a lot.
So, I'd assume 15W.