| 摘要 |
PURPOSE:To ensure constantly suitable ignition timing by parallelly connecting a main transistor to a sub transistor and two resistance type potential dividers and turning of both the main and sub transistors by means of a junction type field-effect transistor according to the voltages developed at the voltage divided output points of the respective resistance type potential dividers. CONSTITUTION:A sub transistor 8 and both the first and second resistance type potential dividers 17 and 18 are parallelly connected to a main transistor 6. The series circuit consisting of a junction type field-effect transistor 26 and a resistance 16 is connected between the first voltage divided output point 24 of the first resistance type potential divider 17 and the base of the sub transistor 8 and the gate G of said transistor 26 is connected to the second voltage divided output point 28 of the second resistance type potential divider 18. A voltage is applied to both the gate G of the field-effect transistor 26 and the base of the sub transistor 8 in sequence by the trigger voltage developed at the second voltage divided output point 28. Consequentially turning on the sub transistor 8 causes the main transistor 6 to be turned off so that a high voltage is induced to be developed at the secondary winding 3, whereby sparking an ignition plug 4 to be discharged electrically. |
