Peltier Temperature Controller

I needed to control the temperature in an enclosure for fly experiments, including getting rid of the waste heat from several cameras and a projector. I decided to use a high-power Thermoelectric/Peltier Module, with heatsinks on the inside and outside of the enclosure. I created a driver that could use a PID loop coupled to a bi-directional buck converter to drive the peltier at -12 to 12 V.

To bi-directionally drive the Peltier I used an H-bridge circuit. Because it is much better (efficiency and Peltier longevity) to drive a Peltier with variable DC rather than PWM or other switching schemes, I used an inductor capacitor output stage to turn the H-bridge into a bi-directional Buck converter.

Setpoint and PID parameters can be controlled via a rotary encoder and LCD screen on the front panel, or via USB-serial from a computer. Current temperature, output level, and other stats are reported via both of these channels as well.