I have built a dummy load (on breadboard) similar to that in Dave's video. I replace the FET with a 2N3055 BJT and use a LM358 dual op amp instead of LM324. Modifications are due to the lack of suitable parts instead of functionality hacks. It seems to be working fine. My plan is to build it up and fit everything into a nice die cast aluminium box which also serves as a heat sink (I may add an extra TO-3 heatsink on top.
Now I don't have a nice 10 turn pot, and if I did have one, it might be too big for the box. I'm thinking of using a barebone arduino (or just a ATTINY chip) to generate PWM signals to replace the pot, is it a bad idea? I've finished the code and linked the two together - everything seemed fine, but just want some different opinions.
Thanks