| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a dimmer in which control fault at the vicinity of the lowest limit of light control can be avoided even if the type and number of connection of the load, or fluctuations of components are not taken into consideration beforehand, and the light control range can be established appropriately. <P>SOLUTION: The dimmer comprises a closed circuit in which a two-way switching element Q1 having a self hold function, an inductive element Li, lighting loads 41, 42, and an AC power supply 1 are connected in series, and has a control circuit 23 for phase controlling the two-way switching element Q1. The phase control is a DC trigger type in which drive voltage is continuously given while the two-way switching element Q1 is turned on, and when a capacitive element is connected in parallel with the lighting loads 41, 42, a resistive element Ra which makes a current flow to offset the phase advancing current flowing in the capacitive element is connected in parallel with the lighting loads 41, 42 so that the current of the switching element may be the holding current or less at the time of turning off of the two-way switching element Q1. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
