| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable to perform measurement with accuracy of a reference time of phase control of a dimmer. <P>SOLUTION: A closed circuit is structured by serially connecting a two-way switching element Q1 with a self-retaining function, an illumination load 4 with a capacitative element C2 connected in parallel and an alternate current power source 1, a zero-cross detection circuit 24 is connected at an output end of a rectifying circuit 22 rectifying in full wave the alternate current power source 1, and time measurement is carried out from a rising edge or a trailing edge of a zero-cross detection signal obtained, whereby a phase controlling circuit of a DC trigger system for deciding an arcing phase angle of the two-way switching element Q1, and a chopper circuit of boosting or boosting/stepping down type is connected to an output end of the rectifying circuit connected to the zero-cross detection circuit 24 as a switching power source 22. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
