| 摘要 |
PURPOSE:To obtain a small size ignition circuit with no transistor employed at low cost by a structure wherein a voltage control circuit consisting of a thyristor and a trigger circuit to trigger the thyristor is provided in the ignition circuit. CONSTITUTION:When a switch 5 is closed under the state that gas is emitting from a nozzle 1, the AC voltage from an AC power source 4 is supplied to a diode 9, a resistor 10, a capacitor 11 and a variable resistor 12, resulting in charging the capacitor 11. When the predetermined switching voltage Vr, which is set in advance in a trigger device 13, is reached by said charging voltage, the trigger device 13 turns ON, resulting in sending waved discharge current as indicated in the attached figure 3 from the capacitor 11. When said discharge current is supplied to a control device 14', a thyristor 14 is triggered ON, resulting in supplying voltage to a load 2 in order to ignite the gas. By changing the resistance of the variable resistor 12, the duration for the AC voltage to be charged to the capacitor 11 is changed, resulting in changing the period to trigger the thyristor 14. |
