DIMMER DEVICE

PROBLEM TO BE SOLVED: To provide a dimmer device capable of switching between a dimmer output mode and a direct power supply output mode, and of reducing the rating of a relay for switching the modes. SOLUTION: The dimmer device includes: a phase control circuit 1 with thyristors 1a, 1b, inserted into an alternating current power supply line 8, for phase-controlling alternating current voltage supplied to a load 7; a current sensor 3 for monitoring the output current of the phase control circuit; a relay 4, connected in parallel with the phase control circuit, for turning ON/OFF the alternating current voltage; and a control means 5 for turning ON the phase control circuit at zero-cross timing of the alternating current power supply voltage during the start of output in the direct power supply output mode, for turning ON the relay to output the alternating current power supply voltage when the output current of the phase control circuit turns to be a given value or less, and for turning OFF the relay before turning OFF the phase control circuit when suspending the output. COPYRIGHT: (C)2009,JPO&INPIT