| 摘要 |
PURPOSE:To provide an ignition circuit for enabling ignition at optimal time independent of the revolution speed of an engine, by connecting a circuit including an NPN transistor and a circuit including a reverse blocking tetrode thyristor, in parallel with each other between both the terminals of the primary winding of an ignition coil. CONSTITUTION:A series circuit consisting of a first NPN transistor Tr2 and a resistor R4 coupled to the emitter of the transistor and another series circuit consisting of a resistor R5 and a reverse blocking tetrode thyristor 6 whose anode is coupled to the resistor are connected in parallel with each other between both the terminals A, C of the primary winding 11 of an ignition coil 1. An anode gate provided on the N-base layer NB of the thyristor 6 is connected to the base of the transistor Tr2. A sensitivity adjusting resistor R4 is connected between the anode and anode gate of the thyristor 6. Still another series circuit consisting of a second NPN transistor 7 and a capacitor 8 is provided. One terminal of the last-mentioned series circuit is connected to a cathode gate provided on the P-base layer PB of the thyristor 6 and the other terminal of the series circuit is coupled to the cathode of the thyristor. |
