Burst length proportioning system for controlling electric power

Claim 1

IN A POWER PROPORTIONING CIRCUIT, HAVING A PAIR OF INPUT TERMINALS FOR CONTROLLING A SUPPLY OF ALTERNATING POWER TO A LOAD OR THE LIKE, AS A FUNCTION OF A VARIABLE VOLTAGE SIGNAL BETWEEN SAID TERMINALS, THE COMBINATION WHICH COMPRISES A STATIC LATCHING SWITCH FOR CONNECTING THE ALTERNATING POWER SUPPLY TO THE LOAD WHEN RENDERED OPERATIVE, A DIFFERENTIAL AMPLIFIER COUPLED TO SAID INPUT TERMINALS FOR AMPLIFYING SAID SIGNAL, TRIGGERING MEANS RESPONSIVE TO SAID AMPLIFIED SIGNAL FOR RENDERING THE STATIC LATCHING SWITCH OPERATIVE WHEN THE ALTERNATING POWER SUPPLY PASSES THROUGH ZERO VOLTAGE IN A PRESCRIBED DIRECTION SO THAT SUBSEQUENTLY THE LOAD IS ENERGIZED BY A HALF CYCLE OF THE ALTERNATING POWER SUPPLY VOLTAGE HAVING A PRESCRIBED POLARITY, AND A FEEDBACK LOOP COUPLED FROM SAID LATCHING SWITCH TO ONE OF SAID TERMINALS FOR COUNTERACTING THE EFFECT OF SAID SIGNAL UPON THE TRIGGERING MEANS AFTER A PRESCRIBED PERIOD OF TIME TO CAUSE SAID STATIC LATCHING SWITCH TO BE LEFT UNACTIVATED FOR ANOTHER PRESCRIBED PERIOD OF TIME.