how hot should a schottky get?

what f is it handling ?

Absolute maximum current is 3A, at a forward drop of 0.5 V, so max power dissipation is 1.5W. The typical thermal resistance is 20C/W, so the max temperature rise should be 30 C. Can you keep your finger on a

Any $10 multimeter should be capable of measuring all three parameters.

Thanks for the suggestions guys. left it on for a few more hours, and the temp. didn't seem to get out of hand. Above calculations noted, many thanks. I suspect this is just a poor design, the psu is a tiny crappy circuit board, no regulators in sight just crude diodes and caps. Lots of pcb area was scorched as things obviously ran hot/at the limits of their tolerances from the word go.

Will do some more exhaustive soaktesting and if things deteriorate, will check the voltage drop and current as sugested. For now I've just got it off the bench for more pressing things. regards, B.

Thanks for the suggestions guys. left it on for a few more hours, and the temp. didn't seem to get out of hand. Above calculations noted, many thanks. I suspect this is just a poor design, the psu is a tiny crappy circuit board, no regulators in sight just crude diodes and caps. Lots of pcb area was scorched as things obviously ran hot/at the limits of their tolerances from the word go.

Will do some more exhaustive soaktesting and if things deteriorate, will check the voltage drop and current as sugested. For now I've just got it off the bench for more pressing things. regards, B.

If you have any sort of a spare heatsink, it wouldn't hurt ot use it, might help and can't hurt.

For every 10 C rise in operating temperature the MTBF for a component goes to one half, lasts on the average half as long. So, cooler IS better.

Most of the heat goes out the legs, some out the body.Remember in convection air te rule of thumb is 1 C rise per watt per 100 square inches