@PLCProf posted:Before this gets too far afield, I don't know how you would use the pulsed DC or any AC method without an oscilloscope. If you had a meter was truly peak-reading, as distinguished from peak-responding, you could do it, but those aren't common devices in the hobbyist world.
Well, that's a reasonable point, I never actually considered using AC for these tests. Of course, since I find it tons easier to do this kind of stuff with a 'scope, I don't put much thought into doing it without one!
The simple DC test is the one I figured was easy to do, and I'm sure that will do a basic test. Several years back this issue came up and I tested one using a DC bench supply. I just repeated that test. With a 50V HP supply, I set the current limit at 30ma. Using the 1500W 33.3V TVS at Digikey part, the knee is right at 36 volts, as soon as I ask for more voltage, the current shoots up to 30ma almost instantly. Flipping the part yields the same result.
BTW, if you leave the 30ma flowing for a spell, you can feel the part slowly warming up. I doubt I'm any where near it's power dissipation limits, but it is certainly inhibiting any further voltage increase.