Re: Help Wiring Large (12"x12") Heatbed Through Relay or MOSFET

Thanks for that thorough explanation! Unfortunately, I'm still not following 100%.

I had already ordered this MOSFET:

[www.sparkfun.com]

I'm pretty sure that one should be able to handle the current and voltage with no problems.

When I ordered it, I was planning on using the heatbed output from the board as the gate for a circuit like this:

[www.electronics-tutorials.ws]

Obviously the motor stuff would be replaced with the heatbed.

But you're saying having the onboard MOSFET feeding the new MOSFET like that wouldn't work well because it'd be slow?

I would prefer not to try to reinforce the traces. I can do basic soldering, but I'm not particularly skilled and don't want to screw up the board. Could I do something like on the attached drawing?



Basically what I'm thinking is:

1. Remove the current MOSFET
2. Solder lead from the Gate trace to the new MOSFET Gate
3. Solder trace from + terminal to MOSFET source
4. Solder trace from MOSFET drain to heatbed
5. Solder trace from - terminal to heatbed

Would that work?

Edit: I think I actually accidentally reversed + and - on that drawing, it looks like it's negative that goes through the MOSFET? Does that mean I need a P-type MOSFET or an N-type MOSFET? Luckily I ordered both, so I can use either one.