HOLD ON A MINUTE !!!! I wasn't 100% done with my diodes... still had my small Zener diodes to process. Well I had already bagged them up and labeled based solely on what was marked on them, but I didn't pull the datasheet to look at the specs in detail. So I did just that.
I have BZX, ZPD, ZPY and ZTK temperature compensated series. Easy.
But have also two that cause me trouble :
1)
"
BYV 10 50 " ... looks all the world like a 10V Zener, tiny blue glass package, but can't find a datasheet for that. Plus, I tested it and it's not a 10V Zener... went up to 30Volts, what the lab supply allows.
So instead it looks like I might be mistaken and instead it's a not a Zener but more likely a BYV10-50 diode. BYV10 does exist, and it's a Schottky diode, 1Amp. DMM says yes it's likely to be right since they drop 0.165V. But... the datasheets I can find say that a BYV10-50 does NOT exist. Only the 20/30/40 which represents the max reverse voltage. OK the datasheet is old and my diodes look brand new, so maybe over the years they extended the rang and created a 50V version. So OK let's go for that. So as sanity check, I decide to test teh voltage drop at full current, as indicated in the datasheet. It says that at 1A, it should drop 0.55V. Sounds about right for a Schottky at the current, so I am happy with that. So I put the diode across the lab supply terminals, using the current limit knob to slowly increase forward
current and watch voltage at the same time. Well guess what... at 1.0A, instead of 0.55V I get 2.2V !!!!
WHAT ?! I want my money back !!! Does not make any sense... even for a "normal" diode 2.2V is silly high, not even plausible ! So I don't know what's going on.... factory rejects ?
2)
"
PHC 5V1 " ... couldn't find anything about that either. Looking more closely and Googling harder... looks like it should rather be read as " C5V1 PH ", and it would be Philips equivalent for the BZX55C.
OK, so at least THIS ONE is really a Zener, that's a good start. So, I test them (I have x3 ) on a bread board with a 1k series resistor... increase the supply voltage slowly, watching for the 5V1 mark and....at 5V nothing happens... at 30V still nothing ! It behaves like a regular diode not a 5V1 Zener ! Diode failed open circuit ? Nope, all 3 test good, 0.7V drop. So neither shorted nor open circuit.
so they are counterfeit ? Or the factory made a mistake, they made regular rectifier diodes and mistakenly marked them as a Zener ?!
Tough luck !
So be it those fake Zener and horrible Schottky... I guess only thing to do is put them all in the trash bin...
02H10 going to bed.....