| 摘要 |
PURPOSE:To perform dimmer control over a lighting load at specific dimmer level even if the frequency of a power source is different by generating a trigger signal having a phase angle corresponding to the power source frequency without being affected by a noise. CONSTITUTION:The control circuit 19 of the terminal device 3a for dimmer control when accessed from a central controller determines the phase angle corresponding to the dimmer level of dimming data according to the power source frequency set with a switch 16 for power source frequency setting. A control circuit part 19 counts the time from the zero-cross detection time of a zero-cross detection part 15 and generates the trigger signal for the phase control element 13 of a dimmer circuit 12 at the timing corresponding to said phase angle. This trigger signal is generated having the phase angle corresponding to a specific dimmer level and a phase control element 13 controls the phase of a commercial power source AC to dim the lighting load L. |
