CONTROL APPARATUS

A control apparatus comprising a switch controlling current flow to an inductance means which is coupled with a controlled element. A free wheeling resistor is connected in parallel with the inductance means and defines a path for reverse flow of induced current therethrough during collapse of the magnetic field in the inductance means. A heat responsive control circuit is provided for controlling a controlled device and includes a heat responsive element disposed in heat exchange relationship with the resistor whereby when the switch is turned on current during positive going half cycles will be directed through both the resistor and inductance means, and the current induced by collapse of the magnetic field in the inductance means will flow in the reverse direction through the resistor thereby permitting continued flow in the forward direction through the inductance means and after a selected time the self-heating of the resistor will heat the temperature responsive element to actuate the control circuit and, consequently, the controlled device.