| 摘要 |
PURPOSE:To prevent generation of high voltage at the secondary side of an ignition coil, by providing a differentiating circuit to the output side of a power transistor, controlling a current, flowing in a base of said transistor, and arranging its collector current to a gentle rise-up waveform. CONSTITUTION:If output (a) from a transistor driver circuit 1 is input to the base of a transistor T1, output of its collector is inverted to become as shown in (b). This output (b) is differentiated by a capacitor C2, and input voltage to the base of a transistor T2 is gradually decreased its level as in (c). In consequence, a transistor T3 is turned on for its base voltage at a prescribed level, for instance, at least V, and a current flowing into the base of the transistor T2 is smoothed its rise-up as in (e) by a current (d) bypassed to a collector of the T3. Accordingly, high voltage can be prevented from generation at the side of a secondary winding 2B of an ignition coil 2 when the T2 is turned on. |
