| 摘要 |
PURPOSE:To contrive to prevent the discharge of a raw gas by a method wherein a contactless igniter is provided with an advancing circuit for advancing the cutting-off timing of a sort- circuit and a delaying circuit for delaying the timing, both the circuits are prevented from operating at the time of low-speed revolution, the advancing circuit is operated at the time of intermediate-speed revolution and the delaying circuit is operated. CONSTITUTION:At the time of low-speed revolution, when a voltage A is induced in a primary winding 3 by the rotation of a magnetic means 2, a base current is supplied to a transistor 7 and a short-circuit current flows in the short-circuit 6. During this, a transistor 9 is turned ON to thereby bypass the base current, the transistor 7 is rapidly turned OFF, cutting off the short-circuit current, and a high voltage is induced in a secondary winding 4. Next, at the time of intermediate-speed revolution, an SCR 17 of the advancing circuit 8 is triggered through a detecting circuit 10, the base current for the transistor 7 is bypassed and the short- circuit current is reduced, so that the terminal voltage of the primary winding 3 is raised and the cutting-off timing of the short-circuit current is advanced. At the time of high-speed revolution, an SCR 16 is triggered by an SCR 15 and the delaying circuit 12 is operated, so that the current passing through the short-circuit 6 is bypassed and the turning-off timing of the transistor 7 is delayed. |
