US Patent 10104718 Temperature detection and control system for layered heaters

A system for detecting and controlling temperature of a layered heater is provided that includes a layered heater having in one form a substrate, a first dielectric layer disposed on the substrate, a sensor layer disposed on the first dielectric layer, a second dielectric layer disposed on the sensor layer, a resistive heating layer disposed on the second dielectric layer, and a third dielectric layer disposed on the resistive heating layer. An overtemperature detection circuit is provided in one form that is operatively connected to the resistive heating layer. The circuit includes a resistor, the sensor layer, and an electromechanical relay in parallel with the sensor layer. The sensor layer defines a material having a relatively high TCR and the resistive heating layer defines a material having a relatively low TCR such that a response time of the control system is relatively fast.