Tengda Electronics offers numerous temperature controllers and power supplies. Our temperature controllers use fast pulse-width modulation to provide control that does not cause harmful thermal cycling of the thermoelectric (Peltier) device unlike common on/off type controllers. Usually, the controller modulates the power output to a Peltier device from a single, constant-voltage power supply. However, if the operating voltage of the Peltier device is less than the minimum input voltage requirement of the controller, then many of our controllers can be used with two power supplies. One power supply is used just for the electronics of the controller while the other power supply provides controller-modulated power to the Peltier device. If a true linear-output control system is desired (for applications extremely sensitive to electrical noise) Tengda Electronics can be used as the control head for high-power, variable-output linear supplies.