I have a Peltier unit (http://www.cui.com/product/resource/cp60.pdf) that I am using to heat a solution. I have a temperature probe in the solution that is measured by an external thermometer and provided as a voltage value. I want to regulate the current going to the Peltier to keep the solution temperature constant.
I have all the Arduino code setup appropriately, however my circuit is the problem. The MOSFET I am using (http://www.cui.com/product/resource/cp60.pdf) gets very hot very quickly. I've put a small heatsink on it but I'm fairly certain the problem is my circuits knowledge.
I have the gate of the MOSFET connected to the PWM output from the arduino, and then going to GROUND via a 10k resistor. I have the drain of the MOSFET connected to the black terminal of my peltier. I have the source of the MOSFET connected to GROUND. The red terminal of my peltier is connected to V+ of my power supply. The GROUND of the board is connected to the V- of my power supply. This is all on a breadboard (not sure if this is ok?).
My power supply is set to 15V and a current limit of 2A. I believe the 15V is within the range required for Vgs on the data sheet. I've measured the voltage between the gate and the source and I see it transition from 0-4.9V as the Arduino's output increases - which tells me that the MOSFET is being switched on/off.
Any suggestions appreciated.