| 摘要 |
PROBLEM TO BE SOLVED: To employ at least one discharge lamp in an automobile to ensure two different functions of generating light from a tail lamp and from a signal lamp. SOLUTION: In a method for turning on at least one discharge lamp, a discharge lamp LP, specifically a neon lamp is turned on with firs-t low power for generating light from a tail lamp of an automobile, and is turned on with second high power for generating light from a signal lamp, preferably a stopping lamp. This lighting method is realized by voltage converters T1 and T2 for elevating an automobile-mounted power source voltage to an AC voltage of medium frequency. The compensation of change in the automobile-mounted power source voltage and the power control of the lamp are performed by a pulse width modulation method. Therefore, this circuit device has a control loop equipped with a drive device for the voltage converters T1 and T2, an operation amplifier OP, and voltage dividers R20 and R21 capable of switching between two setting values by an electronic switch. In order to effect switching between lighting of the tail lamp and of the signal lamp, effective voltage divider resistance in the control loop is switched by the electronic switch. |
