I started on this quest because I needed to connect my programmable supply (KD3005P) 30V-5A to the PV input of a Landstar 1024B PWM Charge controller to test out the charging functionality of the controller and see what affect it has on the load. I didn't have good sunlight to run an actual panel. My programmable supply has current limiting features and I've read that some PWM controllers will actually short the PV leads together to drop the voltage. So I thought this was fine.
I use this charge controller to control the load and sometimes for different projects, when I don't have panels, I put a dumb lead acid battery charger at the PV input. But I'm worried now that perhaps that could kill my supply and I want to better understand the different types of PWM Controllers.
From what I gather, PWM are different from MPPT in that PWM do not vary switching to determine maximum power - just constant current/voltage or following through different charging states that switch between the two. This question is not about MPPT.
Do pwm controllers implement boost/buck converters? Most I've seen are just buck. Is it common to short the PV input? Is it typically safe to connect a DC supply to the PV input of a controller or is that only for certain topologies? If so, which?
