Solid state oven temperature control

Claim 1

A CONTROL CIRCUIT FOR A LOAD CIRCUIT WHICH INCLUDES RELAY CONTACTS IN CIRCUIT WITH HEATING MEANS AND A POWER SOURCE, SAID CONTROL CIRCUIT BEING ADAPTED TO BE CONNECTED TO A VOLTAGE SOURCE AND INCLUDING: (A) ACTUATING MEANS; (B) CONTROLLABLE SWITCHING MEANS IN A CIRCUIT WITH SAID ACTUATING MEANS AND CAPABLE OF ASSUMING A CONDUCTIVE STATE DURING WHICH SAID ACTUATING MEANS IS ENERGIZED OR A NON-CONDUCTING STATE DURING WHICH SAID ACTUATING MEANS IS DE-ENERGIZED; (C) ACTIVE MEANS HAVING CONDUCTIVE AND NON-CONDUCTIVE MODES OF OPERATION FOR CONTROLLING THE STATE OF SAID CONTROLLABLE SWITCHING MEANS; AND (D) TEMPERATURE DEPENDENT BIASING MEANS FOR DETERMINING THE MODE OF OPERATION OF SAID ACTIVE MEANS, SAID BIASING MEANS INCLUDING: (1) A FIRST RESISTIVE PORTION HAVING A MAGNITUDE PROPORTIONAL TO THE TEMPERATURE BEING SENSED, (2) A FIRST IMPEDANCE CIRCUIT FOR USE IN A NORMAL COOKING MODE, (3) A SECOND IMPEDANCE CIRCUIT FOR USE IN A HEAT CLEANING MODE, AND (4) SWITCH MEANS FOR SELECTIVELY CONNECTING SAID FIRST RESISTIVE PORTION TO SAID FIRST IMPEDANCE CIRCUIT OR TO SAID SECOND IMPEDANCE CIRCUIT TO ESTABLISH THE MODE IN WHICH THE CIRCUIT IS TO FUNCTION.