| 摘要 |
PURPOSE:To make it possible to surely discriminate between normal and reverse revolutions of an engine, by peak-holding one polarity side of a bipolar signal generated in a signal generator and having different peak values, and by comparing the sum of the output thereof and the output of the signal generator with a reference value. CONSTITUTION:Since a signal generator 1 issues outputs having waveforms which are different in magnetic flux variation between normal and reverse rotations of a rotor 1a, the signal generator 1 issues output waveforms (a), (a'), as shown in the drawings, upon normal and reverse rotations, respectively. Therefore, the negative peak-hold outputs exhibit signals having different absolute values. Then, when the output (b) of a peak-hold circuit 2 is added to the output (a) or (a') of the signal generator 1 in an adder 3, the added output upon normal revolution shows a waveform alternately changing its polarity, but upon reverse revolution shows a waveform only having a negative polarity. Accordingly, the added output (c) is compared with a reference voltage VT in a voltage detecting circuit 4, and the output thereof is used as an ignition signal (which is not generated upon reverse direction) to energize an ignition coil 6. |
