| 摘要 |
PURPOSE:To make constant the steady primary current interval by comparing the primary current of ignition coil under jumping with that under no jump then holding the jumped level and feeding primary current to the ignition coil. CONSTITUTION:Constant current control section 160 for receiving the voltage corresponding with the current flowing through a current detection resistor 150 for detecting the primary current of an ignition coil 180 and controlling the primary current to predetermined level is provided. While a sample hold circuit 140 for holding the voltage corresponding with the primary current at the start of power supply to said coil 180 and an integration circuit 110 for producing a signal indicating the rising of time constant corresponding with that of said coil 180 at the start of power supply are provided. Then the outputs from said circuits 140, 110 are compared and fed to said control section 160 if the former is higher while a setting voltage is fed through said control section 160 to an analog signal switching circuit 120 if the former is lower. |
