Two-wire layered heater system

A layered heater comprising:

• a substrate;
• a resistive layer disposed on the substrate, the resistive layer having sufficient temperature coefficient of resistance characteristics such that the resistive layer is a heater element and a temperature sensor;
• a protective layer disposed over the resistive layer;
• a single set of electrical leads consisting of only two electrical lead wires connected to the resistive layer;
• and
• a two-wire controller including a power controller and a microprocessor and connected to the resistive layer through the single set of electrical leads, wherein temperature information of the layered heater is provided on command from the resistive layer to the two-wire controller through the single set of electrical leads by an output voltage, the two-wire controller determines the temperature of the layered heater using the resistance of the resistive layer with the microprocessor, and the power controller supplies a power directly to the resistive layer to control the temperature of the layered heater through the single set of electrical leads, wherein the two wire controller includes only a single set of electrical leads consisting of only two electrical lead wires connecting the two wire controller to the resistive layer.