Arduino Controlled Variable Heater


I currently have a setup where I am using an Arduino Mega running off a 12V battery to read 16 thermistors. I am now trying to add a variable heater to this which will consist of applying variable power to a Nichrome resistance wire. However, I am struggling to find a way to vary the power being applied to the wire which can be controlled by an arduino. Does anyone have any suggestions?

I am only interested in the power and not the actual temperature so I do not believe a PID is necessary.



first, do the OHM's law math on the wire

voltage, resistance, amps, etc

if we assume your power will be a few amps, then a MOSFET might be the solution. this is where the data sheets come in. make sure things are within the power ranges.

putting your DC power to the wire, then connect the wire to the FET, then the FET to ground. the FET will act like a switch. the most common ones go between your load and ground, and not between your power and the load.

( this is NOT the same for AC, you need different parts )

the FET has a signal input pin.

You connect a resistor, 1k or some such to your Arduino output pin to the FET The output pin is designed for PWM, on an official board has a ( ~ ) next to it.

when you pulse that FET, it will pass power or not

the faster it pulsed, the more power, the hotter the wire.

tomctom: DC

I am kinda guessing the 12V battery as my first clue.