Photoelectric controller

Claim 1

A PHOTOELECTRIC CONTROLLER FOR CONNECTING A LOAD TO ALTERNATING CURRENT SUPPLY LINES COMPRISING, IN COMBINATION, A TIME-DELAY RELAY FOR ENERGIZING THE LOAD FROM THE SUPPLY LINES, SAID TIME-DELAY RELAY HAVING SPACED CONTACTS AND HEAT RESPONSIVE MEANS INCLUDING A MOVABLE BISTABLE CONTACT ELEMENT FOR ENGAGING EITHER OF SAID SPACED CONTACTS, SEPARATE HEATER ELEMENTS ELECTRICALLY CONNECTED TO SAID SPACED CONTACTS FOR OPERATING SAID HEAT RESPONSIVE MEANS TO MOVE THE BISTABLE CONTACT ELEMENT UPON ENERGIZATION OF EITHER HEATER, A SECOND RELAY HAVING SPACED CONTACTS ELECTRICALLY CONNECTED TO SAID HEATER ELEMENTS AND AN ARMATURE FOR OPENING AND CLOSING AN ELECTRICAL CIRCUIT TO EITHER CONTACT OF THE SECOND RELAY TO ENERGIZE EITHER OF SAID HEATERS, THE CIRCUIT TO SAID ENERGIZED HEATER BEING INTERRUPTED UPON OPERATION OF SAID BISTABLE CONTACT ELEMENT, SAID SECOND RELAY BEING PROVIDED WITH AN INDUCTION COIL FOR MOVING SAID ARMATURE, A CAPACITOR CONNECTED IN SERIES WITH SAID COIL ACROSS THE SUPPLY LINES TO FORM A RESONANT CIRCUIT AND A PHOTOCELL CONNECTED IN PARALLEL WITH A PORTION OF SAID RESONANT CIRCUIT TO CONTROL ENERGIZATION OF SAID INDUCTION COIL IN RESPONSE TO CHANGES IN LIGHT LEVELS.