| 摘要 |
PURPOSE:To enable easy dimming by connecting the collector of a photo-coupler to one end of a light-flux adjusting resistor in a dimming circuit and the emitter to its other end so as to supply digital signals to the anode of the photo-coupler without using controls or the like. CONSTITUTION:When a switch 10 is pressed, an electric current flows through a light emitting diode of a photo-coupler 8 to turn ON between a collector and an emitter, which is followed by shortcircuiting of a light-flux adjusting variable resistor, so that the resistance value of the light-flux adjusting resistor is decreased almost zero equivalently. When the switch 10 is released on the other hand, no electric current flows through the light emitting diode of the photo-coupler 8 to turn OFF between the collector and the emitter, so that an original resistance value is recovered. With this, it is possible to dim by changing the continuity angle of a bilateral thyristor. Thus, dimming is possible only with digital signals without adjusting controls manually. |
