GB1136243A - Ignition systems - Google Patents

Abstract

1,136,243. Ignition systems. ROTAX Ltd. April 28, 1966 [March 26, 1965], No.12818/65. Heading F1B. An ignition system comprises in combination a capacitor means for charging the capacitor, a plurality of trigger devices which when conductive permit discharge of the capacitor to produce a spark, a voltage sensitive device and a plurality of transformers, the primary windings of which are connected in series with the voltage sensitive device across the capacitor. The voltage sensitive device conducts when the voltage across the capacitor reaches a predetermined value so that current flows in the primary windings of the transformers each having a secondary winding and the secondary windings being connected to the plurality of trigger devices respectively, the arrangement being such that when a voltage is generated in a secondary winding the trigger device associated with that secondary winding will conduct. The system further includes switch means operable to determine which transformer turns its associated trigger device on when the voltage sensitive device conducts. As shown the transformers are provided with tertiary windings 40, 38 which have one end connected to a relay contact 39 operable by a relay 16. When the relay 16 is energized the contact 39 bridges the winding 40. When the gap 32 breaks down a pulse is produced in the winding 37 which causes the device 27 to become conductive so that the main discharge path for the capacitor 29 is through the plug connected to the terminal 26. In a modification either the first transformer or the second transformer is saturated instead of short circuiting one of the windings 38, 40. The invention can be applied to circuits in which more than two plugs are to be used alternatively.