LED DIMMING APPARATUS

摘要

An LED dimming apparatus comprising current regulating means (a constant current circuit (6)) for variably controlling a magnitude of a current flowing through an LED load (4), switching means (a transistor (Q1)) for intermittently controlling the current flowing through the LED load (4), and dimming control means (a microcomputer (5)) which receives a dimming signal outputted from a dimmer (1) for controlling the current regulating means and the switching means. When the dimming signal outputted from the dimmer (1) is on a higher side of a predetermined brightness level, the dimming control means sets the current flowing through the LED load (4) to a continuous current, and dims the LED load (4) according to the magnitude of the flowing current. When the dimming signal outputted from the dimmer (1) is on a lower side of the predetermined brightness level, the dimming control means sets the current flowing through the LED load (4) to a pulsed current and dims the LED load (4) by varying an average of its waveform. This LED dimming apparatus is unlike to generate noise even at a large LED current, and unlike to cause variation in brightness even in the case of deep dimming.