I received a MATRIX PEL-8150 Programmable DC Electronic Load for xmas this year. It's great for testing DC power supplies, but for some reason it seems to kill switching MOSFETs and I have no idea why.
I typically just use CC mode on the PEL-8150 because for some reason CR mode seems a bit wacky on the PEL-8150: If I set it for a specific resistance and test with my meter the tested resistance value is not the same as what is configured on the PEL-8150. Probably a separate issue, and I am assuming it's because the PEL-8150 only approximates a resistive load in this mode - but this could be related to burning up MOSFETs so I am mentioning it.
What works is applying a DC voltage to the MOSFET gate first, then enabling the PEL-8150 load input via the menu. Afterwards I can increase CC current value up or down no problem. But if the PEL-8150 load is on before applying voltage to the gate, and then I apply DC voltage to the MOSFET a bunch of clicking may happen in the PEL-8150 - and before I know it the MOSFET has had way too much current pass through it and lets out the magic smoke.
This is of course dependent on the amount of current I have supplying from the power supply, but I wouldn't expect the PEL-8150 to over current the load like this just because the MOSFET switches on. Don't even get me started on PWM output from MOSFETS, that's how I first discovered this interesting feature when testing a PWM motor drive.
Furthermore, in the working case, if remove DC voltage to the MOSFET gate then the PEL-8150 will do a bunch of clicking and disable the load input. No error or anything, it just disables the input for some reason.
I realize programmable electronic loads have active circuitry inside to do their magic - but I just wouldn't have expected this to happen. And because I don't understand why it's happening, I really have no clue as how to safely test MOSFETS (or who knows what else may be susceptible to this) safely using the PEL-8150. I was really excited to have at xmas because I thought it would make testing all sorts of loads much easier.
So any help, pointers, or advice on this topic are highly appreciated.
Thanks in advance!