| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the number of constituting parts, to reduce the size and to lower the production cost of an igniter by providing a trigger circuit which is subject to an ON-OFF control of a control part and makes a transformer for generating a high voltage between a discharge gap generate the resonance and using a photothyristor as such a trigger circuit. SOLUTION: When one side S1 of an alternating current 10 is set to a positive side and the other side S2 of the alternating current 10 is set to a negative side, the current flows through a resistance R1, a diode D3, a condenser C1, a primary coil of a transformer TR1 in sequence and is charged in the condenser C1. On the other hand, when one side S1 of an alternating current 10 is set to a negative side and the other side S2 of the alternating current 10 is set to a positive side, no current flows because of the diode D3. When a trigger current is fed to the input side of a photothyristor PS1, the PS1 is turned on and the electric charge of C1 is discharged by way of the primary coil of TR1. In this condition, the first coil of TR1 and the C1 are short-circuited and are resonated by PS1 and the reverse current flow through a diode D4 and a pulse current is boosted by the PS1 so that a spark is generated in a discharge gap by way of the transformer TR1.</p> |
