What where the MOSFETs?
I was recommended a few MOSFETs but things didn't go so well. I'm guessing they weren't up to the amperage and failed the first time I used them (I'm still not 100% sure how a MOSFET works, either).After some digging, it seems I may need to wire a resistor in somewhere with the MOSFET?
A MOSFET is the correct tool to use here, almost certainly an N-channel one. The following discussion assumes an N-channel MOSFET. . . .
A MOSFET is the correct tool to use here, almost certainly an N-channel one. The following discussion assumes an N-channel MOSFET. The key specs on a MOSFET are the on state resistance - Rds(on), rated maximum current and maximum power dissipation (you always should do the math with the Rds(on) and expected current to see how much power it will be dissipating as heat, and make sure that's viable), and the voltage required on the gate to turn it on (Vgs). Typically you'll get a spec for Rds(on) at multiple voltages. "Standard voltage" MOSFETs need ~10v on the gate to turn completely on. These are awkward to use with arduino for obvious reasons. "Logic Level" MOSFETs require only 4.5v (or sometimes less!) on the gate to turn on and are what you should be using. Beware of unscrupulous EBay sellers claiming that standard voltage MOSFETs like the IRF520 on their breakout boards are logic level - always check the datasheet. If they do not give an Rds(on) spec for the voltage you're going to be putting on the gate or less, it is not an appropriate choice. I normally recommend the IRF3708PBF as a decent power MOSFET - it has low Rds(on), can handle tens of amps, and comes in a TO-220 package, so you don't need to solder SMD parts to use it - and it works with gate voltages as low as 2.8v (albeit with reduced Rds(on)). I think that would be appropriate here. Wire source to ground, drain to negative side of load, gate through a ~100 ohm resistor to the pin controlling it, and a 10k resistor between that pin and ground. If you're doing fast PWM (definition of fast depends on the load, duty cycle, and other factors), switching losses can be significant, resulting in excessive heating of the MOSFET (due to conduction while it's between on and off, when resistance is higher). In that case, you can use a "gate driver" IC, designed to deliver very high (and very brief) pulses of current to the gate to minimize the time it spends between on and off; The FL3100 is an example of one of *many* gate driver ICs. As it happens, I sell FL3100's paired with IRF3708's, as well as a few 4-channel breakout boards with high performance MOSFETs with and without an added gate driver in my Tindie store.
Check these :https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=DC+SSR