Hey all,
I’ve read some of the other posts, and I just want to try to simplify a bit. I’ve seen the configurations for dual power supplies, and the schematics, etc… I just want to try to summarize what i’ve read, apply it to my situation and make sure that i’m thinking it thru correctly.
I got a new MK3 heat bed. The connection for it is here:
Now the power supply I want to use is a laptop power supply, 20V 4.5A 90W. I realize I may only get 90 degrees c with it, and i’m okay with that. No worries there. I assume the 20v positive will go to the 24v, and the GND to the GND, after it comes off of the relay.
So, i’m going to assume that I can find a 15v Relay that can handle up to a 30v / 10A DC power, run the power supply thru it, and then hook it up to the control pins where the old board connects to, and we’re good. Atleast thats what I thought…
From what I understand, the velleman board uses PWM to control the bed… which means hooking it straight up will actually pulse the power on off, which may in time blow out my power supply. I saw in a post someone figured out how to change that in the configuration. Is this something I should consider, or just find a way to translate the pulse into on, and then once the pulse stops, then turn it off. Maybe some sort of attiny controller that translates the pulse read into turn on, and then turn off. And if I don’t want to use a relay, I can use a NPN Transistor to control the negative, right, as long as it can handle the voltage coming thru. (MOSFET).
So, That will cover the power portion of it. I had saw some other posts with the layout of the install, so I think i’m okay on that. I will just need to get a refresher course on how this all goes together. I really can’t wait to get on this and set it up.
I welcome all comments and suggestions. Thanks for being a sounding board.
Once I get it all figured out, i’ll start posting the pictures and steps I came up with. Thanks all.
~Doc