| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a phase control device in which a more effective heat dissipation design is applicable and a downsized and inexpensive device of low noise can be achieved. <P>SOLUTION: This phase control device controls a conductive angle of supply electric power and adjusts the electric power flowing from alternating-current power supply 1 to a load 2, and is equipped with a switching element Q1 to on/off the electric power and a control circuit 4 to control on/off of the switching element Q1. When the control circuit 4 carries out a reverse phase control in which the circuit turns on the switching device Q1 at nearly zero point of supply electric power and turns off the switching element Q1 wherein the phase of the supply electric power is nearly 90°, a positive action region of a prescribed time is installed in which temperature elevation by loss of switching element Q1 becomes nearly the same between that of the light control time and that of the wholly energized time in a transition time when the switching element Q1 is turned off. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
