Abstract: Circuit arrangements for use in the generation of sparks for igniting gas at a gas burner assembly whereby the operation is controlled electrically by means of an electronic control circuit which reacts to the presence or absence of a gas flame. The circuit comprises a charging circuit for a charge storage capacitor, a spark output transformer, an SCR switching device for discharging the charge stored in the capacitor and a non-linear conductive element connected between the anode and the gate of the SCR. Therefore when the anode voltage reaches the required value a trigger signal is applied via said non-linear conductive element to the gate to trigger the discharge of the capacitor by the SCR.

Abstract: Circuit arrangements to improve the performance of motor speed control circuits using electronic switching on an AC waveform where it is desired to remotely control the electronic switch without either load current or the load waveforms being present at the controlling element. The voltage across the switching device, during the time it is off, is rectified, and used as the charging voltage for the phase firing circuit, with a resistor capacitor timing network determining the firing of the switching device when the capacitor voltage reaches a predetermined value.