| 摘要 |
PURPOSE:To reduce power dissipation and heat radiation and improve reliability by performing the close angle control so as to attain the injection timing when the primary current of an ignition coil reaches a predetermined current and performing high-energy ignition. CONSTITUTION:When the alternating voltage generated by an AC generator 100 is at the positive side, a transistor 53 is turned on, transistors 54, 59 are turned off, a transistor 60 is turned on, a transistor 62 is turned off, a transistor 63 and a power transistor 64 are turned on, thus feeding the primary current of ignition coil 101. When the energizing current of the ignition coil 101 is increased to reach a predetermined current value, a current flows into the base of the transistor 62, the transistors 62, 63 and the power transistor 64 are controlled in an active region, and the energizing current of the ignition coil 101 is controlled. A thermistor 40 is used for the temperature compensation of a current limit circuit 113. Next, when the alternating voltage of the AC generator 100 is changed to the negative side, the primary current of the ignition coil 101 is cut off and an ignition plug is discharged. |
