Abstract 1,143,210. Controlling burners. CONTROLS CO. OF AMERICA. 10 Aug., 1966 [13 Sept., 1965], No. 35736/66. Heading F4T. In a burner ignition and fuel control system an igniter 12 having spaced electrodes 11, 13 which also act as a flame sensor is connected in the secondary circuit of a transformer 16 of which the primary coil 20 is connected to an electrical source 22 through a pulsing circuit 24 and a fuel control valve 14 electromagnetically operated through a coil 15 connected in an emitter-follower circuit including a transistor 40. When ignition voltage is applied to igniter 12 with no flame, a high voltage is applied to a gate 52 of transistor 40 rendering the latter conductive to pass sufficient current to open valve 14 and when a flame occurs the ionization potential at the electrodes 11, 13 results in a reduction in potential of gate 52 to reduce the current to a holding value. A silicon controlled rectifier 64 controls current flow in a path 62 of a voltage sensitive circuit 60 so that if ignition fails a shunt circuit to ground is established around valve coil 15 to close the valve and cause a lock-out condition which can be reset by the momentary opening of a switch 80 in the main supply line.
AN IGNITION AND FUEL CONTROL CIRCUIT COMPRISING, IN COMBINATION, AN IGNITER INCLUDING SPACED ELECTRODES, MEANS APPLYING A VOLTAGE TO SAID IGNITER TO OPERATE SAID IGNITER, SAID IGNITER REQUIRING A FIRST VOLTAGE FOR OPERATION THEREOF WHEN NO FLAME IS PRESENT AT SAID ELECTRODES AND A SECOND REDUCED VOLTAGE WHEN A FLAME IS PRESENT AT SAID ELECTRODES, VALVE MEANS, MEANS CONNECTING SAID VALVE MEANS WITH SAID IGNITER FOR RESPONSE TO THE VOLTAGE CONDITION ON SAID IGNITER, SAID VALVE MEANS OPENING IN RESPONSE TO SAID FIRST VOLTAGE AND REMAINING OPEN IN RESPONSE TO SAID SECOND VOLTAGE, AND MEANS CONNECTED TO SAID VALVE MEANS AND SAID IGNITER AND RESPONSIVE TO A CONTINUED CONDITION OF SAID FIRST VOLTAGE ON SAID ELECTRODES TO EFFECT A CLOSING OF SAID VALVE MEANS WITH A PREDETERMINED TIME DELAY AFTER OPENING OF SAID VALVE MEANS.
Claim 2
Dependent Claim
135 words
AN IGNITION AND FUEL CONTROL CIRCUIT COMPRISING, IN COMBINATION, AN IGNITER INCLUDING SPACED ELECTRODES, MEANS APPLYING A VOLTAGE TO SAID IGNITER TO OPERATE SAID IGNITER, SAID IGNITER REQUIRING A FIRST VOLTAGE FOR OPERATION THEREOF WHEN NO FLAME IS PRESENT AT SAID ELECTRODES AND A SECOND REDUCED VOLTAGE WHEN A FLAME IS PRESENT AT SAID ELECTRODES, VALVE MEANS, MEANS CONNECTING SAID VALVE MEANS WITH SAID IGNITER FOR RESPONSE TO THE VOLTAGE CONDITION ON SAID IGNITER, SAID VALVE MEANS OPENING IN RESPONSE TO SAID FIRST VOLTAGE AND REMAINING OPEN IN RESPONSE TO SAID SECOND VOLTAGE, AND MEANS CONNECTED TO SAID VALVE MEANS AND SAID IGNITER AND RESPONSIVE TO A CONTINUED CONDITION OF SAID FIRST VOLTAGE ON SAID ELECTRODES TO EFFECT A CLOSING OF SAID VALVE MEANS WITH A PREDETERMINED TIME DELAY AFTER OPENING OF SAID VALVE MEANS.