| 摘要 |
PROBLEM TO BE SOLVED: To surely operate a horn for an automobile only when the drive is directed. SOLUTION: In a usual state, a capacitor C4 is charged with a battery 4 through an exciting coil 31, connecting part 2, resistance R4 for current limiting, and a diode D2. A transistor Q2 turns on and a transistor Q3 turns off by an inducing voltage of a coil 1 caused by oscillation of a LC oscillator 11. Only a charging current of the capacitor C4 and a current to the LC oscillator 11 flow to the exciting coil 31, the current more than a predetermined level does not flow, and a normally opening contact part 32 is turned off. When the transistor Q3 turns on, the on of the transistor Q3 is continued by the charging electric power of the capacitor C4, so that a horn 5 operates surely.
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