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Sunday, August 2, 2009

Computerized and Electronic Ignition

In an electronic ignition, a rotating reluctor and magnetic-pickup coil replace the traditional cam, breaker points and condenser in the distributors of cars equipped for electronic ignition. This system reduces the time between tune-ups. The high spots of the reluctor interrupt the magnetic field of the pickup coil and the permanent magnet. These interruptions, or pulses, are transmitted from the pickup to a nearby electronic control unit. There, the pulses signal a transistor to break the low-voltage sub-circuit and release high voltage from the coil to the spark plugs. The short-lived electronic ignition system was a transition from the points and condenser system to the computerized ignition system. It came into widespread use in the mid-1970s, but there are still a few engines that use electronic ignition.