DIMMING CONTROL CIRCUIT BY FLUCTUATION POWER SOURCE

PROBLEM TO BE SOLVED: To provide a dimming control circuit by a fluctuation power source, that comprises a dimming stabilization unit and a control unit, and that can be applied for driving LEDs and for linearly adjusting the illumination brightness of the LEDs.SOLUTION: The control unit detects an input current of a circuit, and the dimming stabilization unit outputs a holding current when an input power is smaller than a reference value, and stops the output of the holding current when the input power is greater than the reference value. In this way, when the light emitting diodes are adjusted to a low luminance or to a nearly-off state, the operation of the dimming stabilization unit is controlled by using a chip to assure the stability of the dimming operation of a TRIAC. When the light emitting diodes are adjusted to a high or full brightness, the output of the holding current is stopped by using the chip to effectively reduce low-level unnecessary power consumption and to improve the operation efficiency of the entire circuit. 【課題】調光安定ユニットと、制御ユニットと、を備え、ＬＥＤの駆動及び照明輝度のリニア調節に適用できる変動電源による調光制御回路を提供すること。【解決手段】制御ユニットによって回路の入力電流を検出し、入力パワーが参照値を下回るときには調光安定ユニットより保持電流を出力させ、入力パワーが参照値を上回るときには、保持電流の出力を中止させる。このように、発光ダイオードを低照度またはオフに近いに調節されたときは、チップを用いて、調光安定ユニットの稼働を制御して、ＴＲＩＡＣ調光の安定性を確保できると共に、高輝度または全輝度に調節されたときには、チップを用いて、保持電流の出力を断ち切り、低度な無効電力消費を有効に軽減し、回路全体の稼働効率を向上することができる。【選択図】図５