I have a question on the PS and Heatbed. I have an MK3 and a 12v 30 amp PS. The stock PS is crap. Can i use this PS on the controller and finally use my Heat bed?
If it is 12V you probably can. Just check if the ribbon cable can take the higher current load without
too much voltage drop. (can also get hot evetually) I rewired the heatbed with 0.75mm² speaker cable to
minimize the Voltage drop over the cable. I also chose to put a second 24V power supply on the heatbed
and leave the stock 15V supply for the controller. But i still use the stock heatbed.
My wiring is all changed. I didn’t care for the ribbon cable. I just wanted to make sure i didn’t fry the board. Its a 12v 360w PS and a MK3 Heat bed wired for 12v.
The board can take 12V easily.
Velleman drives it with 15V with the stock supply.
I’m not absolutely sure if the onboard traces to the mosfets can take the higher current, but i think they will.
Running the OEM heatbed from 24V via the onboard FET caused no problems. Full current is only for a limited period during warm-up. After that the current is much lower.
Paul, did you connect the 24V to the 15V input?
I believe not, am i right?
I don’t think the 5V regulator on the board can handle 24v input. At least, not long …
Initially I disconnected the high side of the bed from the control board and connected it to the 24V supply (grounds common). I later modified the control board, cutting a track and using the two power connectors for the separate supplies. The original 15v had failed anyway and I snagged a 12V from the draw full of salvaged supplies, so the regulator has an easier life.