Think I'm going to go buy a Peak Atlas ZEN50 Zener diode tester tomorrow. I've needed a zener diode tester on a number of occasions now and setting up a multimeter, power supply and resistor is a pain in the bum.
Anyone got any reason why I shouldn't?
I too would like a way to quickly test Zener diodes. Can't justify the money for a dedicated tester though. Instead I put my Zener need in the balance to strengthen my motivation to get a proper / modern power supply these old HP / Agilent ones with a VFD display every one has but not me, where you can control the short circuit accurately and display the voltage accurately too.
I could just shove the Zener in the jacks of the PSU and limit the current to 1mA and see what voltage that gives me. Then increase the current and see how the voltage behaves.
Now I think of it maybe it's not a good idea : the output caps in the PSU might discharge into the Zener when I connect it, and blow it ?
But if I set the output voltage to Zero and current limit it to 1mA say, then slowly increase the voltage, should be safe ?
Anyway, I could still put a series resistor to limit the current to a safe level. Could make a little test jib with ZIF socket, a resistor, couple 4mm binding posts and I could just grab that whenever I need to test a Zener, grab a couple test leads to connect it to the PSU and that's it.
I think that's how I will go about it. Cheap, simple, efficient... and an excuse to buy a decent PSU.
Back in the day, we used the Calibrate output on a Tek 545b as a voltage source, & hung a probe across the diode.
Unlike modern 'scopes, "Cal" was adjustable right up to around 150v.
The Calibrator has a reasonably high output resistance, so we didn't need a series resistor.
We would start out at 1v or so, then increase the calibrator setting till the display on the 'scope screen suddenly dropped.
That was the zener point of that device.
OK, the resolution was only as good as the screen display, but it was usually near enough, as the vertical gain could be set on the CRO beforehand, using the calibrator normally.