Additional power supply for heatbed
Hello, I have a 3Drag/K8200 DIY 3D-printer and I am currently busy with installing a mosfet controller to fit a additional power supply since the original supply is not good enough to get enough heat to print ABS.
I think I'm almost there to fit everything together, I just want to ask a few questions before blowing anything up (since I am not that great with electronics):
*First of all, I found 3 power supply's laying around and I'm wondering of any of these 3 is good enough to make this setup work:
First one is a power supply of a pc:
12v 32A = 380 watt
second and third one is a power supply of an old laptop:
20v 6A = 120 watt
and
19v 4A = 76 watt (which will be not enough a assume)
https://lh4.googleusercontent.com/-j.../voedingen.jpg
will any of these 3 perform good enough for this situation? (the bed is 80 - 90 watts)
*Second question is the wiring, I drew in paint what I understand of how this mosfet has to be wired (I can be completely wrong, but this is what I understand with my basic knowledge about these things):
https://lh4.googleusercontent.com/-y...schakeling.png
So on the control-board both left pins are positive and both right pins are negative, correct? Weird thing is, on the signal input is no + or - written (at least weird for me, probably this is logic for someone who understands :-))
*Final question:
There is a message on the back of the mosfet-printboard:
https://lh4.googleusercontent.com/-X...4+15+42+33.jpg
what does this normal or inverted means? I'm not that good with this kind of stuff (that's the reason i bought this printboard and did not assemble it myself). I assume I have to solder the "normal" jumper.
And by the way, if you look closely, the normal "jumper" looks like it is already connected to each other..
Thanks for your time ;-)