GB1368807A - Ignition systems - Google Patents

Abstract

1368807 Ignition systems L NELSON-JONES 29 Feb 1972 [12 March 1971] 6645/71 Heading F1B A process for charging the capacitor 11 of an ignition system comprises utilizing the stored energy in the core of a transformer 6 to charge the capacitor, the stored energy being provided by a transistor (5) switching circuit from a primary source of power and the time constants of the circuit components are of such values that the correct relative timing of the charge and discharge cycles are achieved without the use of additional timing circuits or components and the transistor switching circuit is arranged so that the flux level in the transformer is built up to an effectively constant level during each cycle of operation so that on transferring the charge stored in the transformer core 6 to the capacitor of the discharge circuit an effectively constant energy level is achieved in the value of the charge in the capacitor thus ensuring an effectively constant value of the high voltage pulse output to the ignition or spark plugs of the engine despite large variations in the voltage of the primary source of power. The discharge of the capacitor may be initiated at the same instant as or immediately following the initiation of the switch or of the flux in the transformer core and is controlled so that the flux reaches its peak value after the capacitor discharge is complete. The input triggering pulse applied to the terminals 1 may be derived from a conventional ignition contact system with additional pulse shaping components or from a magnetic or photo-electric pick up.