GB1310102A - Spark ignition apparatus - Google Patents

Abstract

1310102 Spark ignition control IGNITERS Ltd 5 June 1970 [6 March 1969] 11848/69 Heading F4F [Also in Division F1] High tension spark ignition apparatus (Division F1) for a burner comprises a full-wave rectifier, such as a diode bridge with diodes D1-D4, which has an input connected to an A.C. supply and a series connected capacitor C1 and primary winding of spark transformer P connected in parallel with an electronic switch S, preferably an SCR, across its output, the capacitor being charged, preferably indirectly, by the output of the rectifier during one halfcycle of the supply, and being discharged through the primary winding on the other half-cycle by the electronic switch which is positively triggered by a signal from the rectifier. A further capacitor C2 connected in the input of the rectifier assists in charging capacitor C1 so that power is drawn from the supply on both half-cycles, capacitor C2 preferably having a capacitance greater than that of C1. During the first quatercycle, as shown in Fig. 2, capacitor C2 is charged, and on the subsequent two quater-cycles capacitor C1 is charged first by the discharge of capacitance C2 then by the positive potential V AB , switch S being non-conducting. On the next full cycle switch S is triggered to conduct and capacitor C1 discharges through it generating a spark across spark gap G. Parallel resistor R3 discharges capacitor C1 when the apparatus is not in use, for safety. A plurality of spark uransformers P may be provided connected in parallel across the output of the rectifier, and each may be provided with an indicator circuit including a Zener diode and a relay to indicate the proper functioning of the apparatus.