| 摘要 |
<P>PROBLEM TO BE SOLVED: To set a control operation corresponding to a characteristic of a dimmer and a dimming characteristic to be realized in a lighting power supply device constituting a lighting system equipped with a phase control type dimmer. <P>SOLUTION: The lighting power supply device includes a control circuit of a transistor, which controls a drive current that is caused to flow to a lamp, receives a pulsating flow converted from AC by a rectifier circuit rectifying the AC whose phase is controlled by the phase control type dimmer and generates/outputs DC voltage/current supplied to the lamp. The control circuit includes: a time-voltage conversion circuit converting time determined by the phase of the voltage, which corresponds to the pulsating current converted by the rectifier circuit, into the voltage; and a terminal which can connect a capacitor of an arbitrary capacity value. The time-voltage conversion circuit allows the capacitor to generate charging voltage corresponding to the phase of the pulsating current. A sample-hold circuit takes in the charging voltage of the capacitor at prescribed timing corresponding to a change of output of a voltage comparison circuit and holds and outputs the voltage till next timing. <P>COPYRIGHT: (C)2013,JPO&INPIT |
