Engine ignition time control unit

Abstract

Abstract PURPOSE:To assure the ignition regardless of malfunctions in a circuit by generating an ignition signal based on the minimum advance angle or a smaller fixed advance angle at a discriminating circuit when no spark advance angle signal appears in an electronic ignition device. CONSTITUTION:The output pulses from a detector 4 generated by disks 5, 6 of a crank shaft are fed into an inverter In1 and an FV converter, and a transistor Tr is turned on by the In1 output, momentarily charging a condenser C, then is turned off. The charged voltage a and the FV output b are compared by A1, and since the output b is increased as the number of revolutions rises and is kept at a constant level in high and low revolution regions, the output c from A1 is kept at L for a long time in the low revolution region. The discriminating circuit 10 compares the changing time of the output from an advance angle circuit 9 with that of an ignition block detector consisting of the disk 5 and the detector 3, and transmits an ignition signal which has appeared earlier. Therefor, in case no output occurs due to malfunctions of the circuit 9 or others, an ignition signal is fed at the fixed advance angle before the top dead point by theta1.

Inventors

• 👤 Hajime Maruyama

Bibliographic Details