| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device which can control a switching element with a simple structure. SOLUTION: An alternate current signal is outputted from a discharge lamp control device and supplied to a control circuit 18 of a discharge lamp lighting device 4 through a signal line 14. In the control circuit 18, full-wave rectification is applied to an alternate current signal from the discharge control device by a full-wave rectifying circuit 19, a pulsating current with twice as big as a frequency of the alternate current signal is made, in accordance with this pulsating current, a light emitting diode LED 1 is lighted, a drive circuit 20 is controlled by switching a photo transistor Q4, and by activating this drive circuit 20, a transistor Q2 and a transistor Q3 are controlled so that they are switched on and off alternately in accordance with the pulsating current. All-wave rectification is applied to an alternating voltage from a power supply cable 13 by an all-wave rectifying circuit 15, and while its pressure is raised by a step-up voltage chopper circuit 16, a high harmonic wave is eliminated by shaping the wavefrom. |
