| 摘要 |
PURPOSE:To prevent the consumption of useless electric power by a method wherein a primary current limiting circuit, in which the limiting amount of the value of the primary current flowed to an ignition coil based on an operating condition signal can be changed, is provided in the compound electric current interrupting capacity and electric discharge type ignition device. CONSTITUTION:In the titled device, an interrupting transistor Tr6 is put ON or OFF by putting ON or OFF a control transistor (driver) which is put ON or OFF by a contact breaker and a high voltage is impressed to an ignition plug through the ignition coil by discharging a capacitor. In this case, the primary current limiting circuit 10 is interposed in a circuit from the driver to the base of said transistor Tr6. The circuit 10 is constituted so that a circuit between the collector and the emitter of a n-p-n Tr11 is provided as the side circuit with respect to the base of the power transistor 6 while the basic of the transistor 11 is provided with a voltage after dividing the voltage from a current detecting resistor 12 by a pair of fixed resistors 13a, 13b and the fixed resistor 14. The transistor Tr15 for selective short-circuit, whose base is connected with a speed detecting sensor 16, is connected to both terminals of the resistor 13b. |
