DETERMINE A SETTING OF A TRIAC DIMMER THROUGH INDUCED RELAXATION OSCILLATION

摘要

A system for controlling power delivered to a lighting system for controlling illumination. The system includes a TRIAC with an input capacitor connected in parallel to a phase delay circuit including a series combination of a potentiometer and a capacitor. A ramp voltage output from the timing circuit is connected through a DIAC to a gate input of the TRIAC. The TRIAC is connected between a DC voltage source and an electrical load. In response to the DC source, the input power storage capacitor, the phase delay timing circuit and the input terminal of the TRIAC have a direct current output voltage higher than a DIAC breakover voltage, used to drive a gate input of the TRIAC. The TRIAC operates in relaxation oscillation mode such that a frequency of oscillation of the TRIAC circuit, as controlled by the timing resistor, can be used to control power to the electrical load.