GB933788A - Spark ignition apparatus - Google Patents

Abstract

933,788. Converting. ROTAX Ltd. Jan. 16, 1962 [Jan. 31, 1961], No. 3583/61. Class 38 (2). [Also in Group XXVII] Spark ignition apparatus comprises in combination a pair of transformers 5, 5a having primary and secondary windings, switch means 11 in circuit with the primary windings and movable between a first position in which one of the primary windings is energized and a second position in which both primary windings are energized, means (transistors 9, 9a) for breaking the circuits to the primary windings intermittently so as to generate a high voltage in the secondary windings, a pair of capacitors 15, 15a connected across the secondary windings through rectifiers 16, 16a respectively, a pair of control gaps 19, 19a each having two spaced electrodes connected across the pair of capacitors respectively so that the control gaps break down when the voltages across the capacitors reach a predetermined value and a pair of conductive bands 25, 25a surrounding the control gaps respectively and connected to an electrode of the other control gap respectively, breakdown of one control gap applying a bias to the band surrounding the other control gap to reduce the breakdown voltage thereof. In use under normal conditions the switch 11 is set so that one or other of the transformers 5, 5a is energized. Where a discharge of greater energy is required the switch is set so that both transformers 5, 5a are energized simultaneously. Either one or two spark gaps may be employed. The terminals 34 are adapted for connection to a source of direct or rectified alternating current. In a modification the transistors are dispensed with and interrupters in circuit with inductors are employed. In another modification each control gap is provided with an additional conductive band.