METHOD OF IGNITION OF FUEL MIXTURE IN INTERNAL COMBUSTION ENGINE AND ITS IGNITION SYSTEM SWITCH Russian patent published in 1996 - IPC

FIELD: electrical equipment of automobile internal combustion engines. SUBSTANCE: AC voltage is fed to electrodes of spark plugs which is obtained due to oscillatory discharge of reservoir capacitor to primary winding of ignition coil. Switch which is used for realization of this method has step-up voltage converter 2 whose inputs are connected to storage battery 3, reservoir capacitor 4 connected to outputs of converter 2 through rectifier 5, thyristor switch 6 which consists of thyristor 7 and backward diode 8, control circuit 9 connected between input of switch 6 and ingintion? moment sensor 10 made in form of contact transistor switch 11 whose control input is connected with Hall microswitch 12 when switch is used in breakerless ignition system. Reservoir capacitor 4 is connected via switch 6 with primary winding 13 of ignition coil 14, thus forming oscillatory circuit together with it. Thyristor switch control circuit 9 has two series RC circuits 18 and 19; circuit 18 consists of capacitor 22 and resistor 23. Discharge resistor 24 is connected in parallel with capacitor 20; discharge circuit 25 which consists of resistor 26 and diode 27 is connected between capacitor 22 and breaker 10. Switch is also provided with transistor switch 28 shunting input circuit of thyristor switch 6. Switch makes it possible to obtain spark discharge in spark plug of required duration which reliably ignites the fuel-and-air mixture. EFFECT: switch control circuit is easy to tune and ensures reliable turning on/off of thyristor switch. 4 cl, 2 dwg