Thermoelectric coolers are solid state heat pumps which have no moving parts and do not require the use of harmful CFCs. Because they have no moving parts they are inherently reliable and require little or no maintenance. They are ideal for cooling devices that may be sensitive to mechanical vibration. Their compact size makes them well suited for applications that are space or weight limited such as portable or airborne equipment. The ability to use TECs to heat as well as cool is great for applications requiring temperature stabilization of a device over a wide ambient temperature range such as laser diodes.
Thermoelectric coolers require smooth dc current for optimum operation.
A bipolar power supply is required for those applications requiring both heating and cooling. Pulse width modulation may be used at frequencies above 1 kHz. Linear proportional, PI or PID control can also be used. While this is the simplest control technique, temperature cycling within the TEC as power is cycled from full ON to full OFF may result in premature failure. One side of the TEC contracts as it cools and the other side expands as it heats.