Electric heater consisting of several field effect transistors connected in parallel or series as negative temperature coefficient resistor heater controls temperature

摘要

Each transistor gate and source electrode are connected by a negative temperature coefficient resistor with good thermal contact with the transistor. Rising transistor temperature lowers the resistor value reducing the gate electrode voltage. This leads to a lower drain current reducing the heat loss and temperature of the transistor. This provide a means of self regulation providing even temperature distribution of the transistors.