| 摘要 |
PURPOSE:To prevent the control pole of a semiconductor switching element from being applied with D.C. power source even if chattering occurs in a stopping switch, by providing a delay circuit in parallel with the stopping switch. CONSTITUTION:In a stopping device 1, wiring is made so that current from a battery 52 is fed to the gate of an ignition thyristor 34 through a resistor 41 and a stopping thyristor 42. Further, a capacitor 44 connected in parallel with a stopping switch 51, for preventing the latter from chattering, constitutes a time delay circuit together with the resistor 41. In this arrangement, when the switch 51 is opened, even if chattering which opens and closes the switch bit by bit due to vibration or the like, occurs, the voltage at the point A does not increase rapidly due to the provision of the time delay circuit, and therefore, it is possible to eliminate erroneous operation. Further, the stopping of ignition is initiated in synchronization with the regular spark position, and therefore, no firing occurs other than the regular ignition even though the stopping switch 51 is opened with any timing, since the stopping of ignition is initiated in synchronization with the regular ignition position.
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