Thanks @Eric_Moy . Looks like I’ll need a few of these. Just noticed the 12V connector looking a bit brown and was probably causing it to short. Is there a guide to set this up?
I don’t know how to link old posts, bit I can try to explain it. The SSR has two sides like a normal relay, the switched side, and the coil side. In essence, when you apply current/voltage to the coil side, you close the switch in a normally open SSR.
So if you are using a single power supply that you are confident can power the bed and electronics, you will be powering the motherboard just the same as now. You will need a second set of power leads coming from the supply. The negative lead will go to your heater, the positive lead will go to one of the terminals on the switched side of the SSR. Another wire will connect the remaining terminal of the switched side of the SSR to the remaining lead of your heater. The terminals on your mother board that originally powered the bed, will now be connected to the coil side of the SSR. So now when the Arduino thinks it’s pumping high current into the bed, it’s actually pumping low current across the coil side of the SSR.
To make sure your power supply is powerful enough, just use ohm’s law. Measure the resistance across the heated bed, then calculate the Current across the heated bed with I=V/R. For my hardware, I have a 2 ohm bed with 12vdc power supply, so the current across my bed is 6 amps which would output a power of 72 watt max, regardless of wattage of my power supply. The only way to increase the power output in the same bed would be to increase the voltage. Just make sure that the heated bed has a high enough voltage and power rating.
Hope that all made sense. Good luck