Silicon-controlled light-dimming circuit, light-dimming method and LED (light-emitting diode) driver applying the same

Abstract

The invention provides a silicon-controlled light-dimming circuit, a light-dimming method and an LED (light-emitting diode) driver applying the same. According to the invention, the silicon-controlled light-dimming circuit is used for receiving a default-phase direct-current voltage signal so as to generate a light-dimming signal to adjust the brightness of a subsequent LED lamp load. The silicon-controlled light-dimming circuit comprises a conducting phase angle signal generating circuit and a light-dimming signal generating circuit, wherein the conducting phase angle signal generating circuit is connected with a rectifying bridge, and is used for receiving the default-phase direct-current voltage signal and generating a control signal for representing the conducting phase angle range of a silicon-controlled rectifying element; and the light-dimming signal generating circuit is connected with the conducting phase angle signal generating circuit, is used for receiving the control signal, an adjustable signal and a clamping voltage signal so as to generate a light-dimming signal, selecting the light-dimming phase angle range amplitude by a constant value signal determined by the clamping voltage signal, and adjusting the amplitude value of the light-dimming signal by adjusting the adjustable signal so as to carry out corresponding translation on the light-dimming phase angle of the silicon-controlled light-dimming circuit.

Description

technical field [0001] The present invention relates to a dimming circuit applied to drive lamp loads, in particular to a thyristor dimming circuit, a thyristor dimming method and an LED driver using the same. Background technique [0002] For the field of lighting, since the thyristor phase control (chopper method) dimming method has the advantages of small size, reasonable price and wide range of dimming power, the thyristor phase control dimming method is currently the most widely used The dimming method is widely used in the fields of stage lighting and ambient lighting. By applying the SCR phase-controlled working principle, by controlling the conduction angle of the SCR rectifier element, a part of the sine wave voltage input by the AC power grid is cut off to reduce the average value of the output voltage, thereby controlling the power supply voltage of the lamp circuit and realizing Dimming function for lamp load. [0003] refer to Figure 1A , shows a schematic bl...

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Problems solved by technology

However, since the characteristic parameters of thyristor rectifier elements are different, the conduction phase angle ranges are different. For different thyristor rectifier elements, the parameters of the thyristor dimming circuit need to be adjusted differently, otherwise, it may be The dimming performance of the thyristor dimming circuit will be reduced, so the existing thyristor dimming circuit is not very versatile

For example, the adjustable phase angle range determined by the silicon controlled rectifier element is preferably 60°-120° phase angle; and when the initial conduction angle of another silicon controlled rectifier element is 75° phase angle, if the same SCR dimming circuit, the adjustable brightness range of the load is correspondingly reduced

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