Electronically controlled automobile ignition system - has time constant circuit supplying pulse of known duration to switch DC supply to transformer generating HV

摘要

The automobile ignition circuits uses a high voltage pulse generator or to ignition coil where supply is a D. C. current. The high voltage being produced by interrupting to supply current. Interruption of the supply current is controlled by an electronic system. This electronic system delivers a pulse where duration is fixed by an R. D. time constant. This time constant is inversely proportional to the supply voltage. The time may be made to vary with the voltage. This is achieved by using a variable resistance (24, 25). The resistance (24) being varied in the opposite series to the voltage in series with a capacitor. Conversely the capacitor (22) may be made variable in the opposite series to the voltage in series with a resistance.