| 摘要 |
PURPOSE:To control a single valve with illuminance corresponding with usage by making the duty ratio variable through variation of pulse width to be fed from a pulse oscillator interlocked with stop, tail and parking switches then controlling the single valve on the basis of said ratio. CONSTITUTION:A pulse oscillator 25 for producing pulses having predetermined period while interlocking with function of stop switch 3, tail switch 4 and parking switch 5 is provided to vary the pulse width with correspondence to each switch 3-5 thus to vary the duty ratio. Since the single valve 12 is controlled on the basis of output from pulse oscillator 25, it can be used as stop lamp, tail lamp or parking lamp with corresponding illuminance. While when varying the duty ratio through variation of pulse width, the turn-on time of drive pulse can be varied and the turn-off time can be made constant, thereby flickering through turning on-off can be prevented. |
