GB902175A - - Google Patents

Abstract

902,175. Ignition systems. BENDIX CORPORATION. May 5,1961 [May 16, 1960], No.16466/61. Class 7(4) [Also in Group XXVI] An ignition system for supplying a spark discharge gap 36 with a continuous succession of pulses of gap discharging voltage, comprises a first source of voltage, pulses 12 adapted to be intermittently energized and connected to the spark discharge gap through a control gap 22, a second source of voltage pulses 37 adapted for continuous operation and conencted to the spark discharge gap and means for preventing current flow from each of the sources of voltage pulses when it is energized into the other source of voltage pulses. In the embodiment shown high intensity spark discharges for initial operation of the engine are provided from unit 12 powered by a direct current source such as a battery 10 and lower intensity stand-by spark discharges are provided by the unit B7 powered by an alternating current source such as an alternating current generator 39 which may be either air driven or driven by the jet engine. When the ignition system is powered by the unit 37 the gap 26, its shunting condenser 27 and the condensers 20 and 24 act as a condenser voltage divider which functions effectively to prevent current flow in the unit 12 other than through transformer 31 and to the spark discharge device 36. When the unit 12 supplies the spark discharge for the device 36 the gap 55 acts as an effective barrier against the flow of any substantial amount of current from the unit 12 into the unit 37. The discharge voltage of the gap 26 is substantially lower than that of the control gap 22. The sheath 57 of the connecting lead is connected to the grounded metallic casing of the units 12 and 37. In a modification the gap 26 and condenser 27 are located within the unit 37. The high frequency step up transformed is incorporated in a separate housing. This modification lends itself conveniently to use for modifying existing systems.