Electrical control device

Claim 1

A CIRCUIT FOR CONTROLLING THE APPLICATION OF ENERGY TO A LOAD COMPRISING A PAIR OF PRIMARY TRANSFORMER COILS CONNECTED TO PRODUCE RESPECTIVE FLUX FIELDS WHICH ARE IN EFFECTIVE OPPOSITION, MEANS TO ENERGIZE THE PRIMARY COILS, A CONDITION SENSITIVE IMPEDANCE ELEMENT CONNECTED IN SERIES WITH ONE OF THE PRIMARY COILS WHEREBY THE FLUX FIELDS MAY BE UNBALANCED, A PAIR OF SECONDARY COILS MAGNETICALLY LINKED TO THE PRIMARY COILS AND ADAPTED TO GENERATE RESPECTIVE SIGNALS RELATED TO THE NET FIELD PRODUCED BY THE PRIMARY COILS, A PAIR OF UNIDIRECTIONAL CURRENTCONTROLLING DEVICES EACH HAVING A CONTROL TERMINAL ADAPTED TO CONTROL THE CONDUCTIVITY BETWEEN TWO OUTPUT TERMINALS. THE CONTROL TERMINALS BEING RESPECTIVELY CONNECTED TO THE SECONDARY COILS WHEREBY THE CONTROLLING DEVICES ARE RENDERED CONDUCTIVE WHEN A NET PRIMARY FIELD OF PREDETERMINED MAGNITUDE EXISTS, A SOURCE OF ALTERNATING CURRENT, THE CONTROLLING DEVICES BEING OPPOSITELY CONNECTED IN PARALLEL ACROSS THE SERIES COMBINATION OF THE SOURCE AND A LOAD, THE CONDITION SENSITIVE IMPEDANCE ELEMENT BEING