Morgan Olsson wrote:

> The cloud came from the power supply, a DIN rail Comatec 24V 800mA out.
> Opening it revealed it had popped i4ts 35V output electrolytic.
> So it had probably been very high output voltage.
> I found it had no crowbar thingy at all.  Why do I buy crap??.


The 3 rules of electronics real estate;
1. run test
2. run test
3. run test
;o)

I've seen 1w resistors that when run at 1W got so
hot the solder melted and they fell out of circuit.
"3 amp" power supplies that caught fire running at
2.5 amps for an hour. And my pet hate are small
power chips rated for 1A or 1.5A that self destruct
when run at their so called rated current. Some
manufacturers are no better than crooks, the worst
being some of the lesser-known Asian brands using
other manufacturers datasheet specs but making
parts nowhere near that good.

I'm still struggling to find good schottky 1N5819
diodes. So far i've tested 3 brands marked as
1N5819, with huge differences between the saturation
voltage Vf and even differences in the shape of the
curve.

It's getting nasty, the days of buying a part by
number and expecting it to perform are long gone...
:o(
-Roman

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