| 摘要 |
PURPOSE:To make a fixed delay timing signal securable with a simple constitution, by controlling a constant in time of condenser discharge corresponding to an engine speed, with an impedance conversion element which varies a discharge current according to output voltage of an F-V conversion circuit. CONSTITUTION:A reference ignition timing signal out of a waveform shaping circuit 5 is impressed on an analog switch circuit 13 and a NAND circuit 22 of a default circuit 12, and for the duration of this H output period, analog switches 15b and 15c are closed, opening another analog switches 15a and 15d, and an L output period becomes reversed. According to these output H and L periods, charging and discharging of first and second condensers 18 and 19 are repeated whereby a discharge time constant for these condensers 18 and 19 is controlled via an impedance conversion element 17 which varies a discharge current according to output voltage of an F-V conversion circuit 16. Thus, such a signal as being delayed in timing control to the reference ignition timing signal is secured independent of an engine speed, and timing control delay time is possible to make it into sameness so that an amplifier to be impressed with a delay timing signal and an ignition coil are prevented from thermal breakdown. |
