On Nov 3, 5:40*pm, b wrote:
On Nov 3, 8:15*pm, spamtrap1888 wrote:



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
55C temp surface?

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.

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