Light control device and light control system and phase control device in studio, theater, etc.

摘要

PURPOSE: To provide a light control device without problems of noise and stating delay of a load, and light control system for a studio, theater or the like using the device. CONSTITUTION: The light control device DM is provided with a first phase control circuit PC1 equipped with a self arc-extinguishing control element inserted into an alternate-current power source line 11 and controlling phase of alternate-current voltage, a second phase control circuit PC2 equipped with a thyristor inserted into the alternate-current power source line 11 and controlling phase of the alternate-current voltage, a load current detecting means CD detecting a load current, and a control means directing a power source voltage half-wave to perform a phase control by the first phase control circuit PC1 first, and then, after the load current detected by the load current detecting means CD reaches a given value, making the second phase control circuit PC2 to perform a phase control in place of the first phase control circuit PC1.