LED linear current-constant light modulation circuit

Abstract

The invention discloses an LED linear current-constant light modulation circuit. An LED lamp set, a linear current-constant circuit for driving the LED lamp set and a light modulation compatible circuit for adjusting the brightness of the LED lamps set are included; the linear current-constant circuit comprises a silicon controlled rectifier light modulator, a bridge type rectifier diode, a third resistor, a first linear current-constant controller and a fifth resistor; the silicon controlled rectifier light modulator, the bridge type rectifier diode, the LED lamp set, the first linear current-constant controller and the fifth resistor are connected in series successively; the third resistor is connected in parallel between the positive polarity output end and the negative polarity output end of the bridge type rectifier diode; and the light modulation compatible circuit comprises an RCD sinking circuit and / or an active discharge circuit, the RCD sinking circuit is used to smoothen the instant conduction current of a silicon controlled rectifier in the silicon controlled rectifier light modulator, the active discharge circuit is used to keep the silicon controlled rectifier in connection, and the RCD sinking circuit and / or the active discharge circuit is connected to the linear current-constant circuit in parallel. The LED linear current-constant light modulation circuit is compatible with the silicon controlled rectifier light modulator, the effect of stepless light modulation is achieved, the circuit is simple, and the size is small.

Description

technical field [0001] The invention relates to the technical field of LED electric light sources, in particular to an LED linear constant current dimming circuit. Background technique [0002] LED is called the fourth-generation lighting source or green light source. It has the characteristics of energy saving, environmental protection, long life, and small size. It is widely used in various indications, displays, decorations, backlights, general lighting, and urban night scenes. With the advancement of LED lighting technology and the continuous reduction of costs, LED lights are replacing traditional incandescent lamps and energy-saving lamps in large quantities, and the compatibility requirements of traditional incandescent lamps for traditional thyristor dimming are also applied to LED lighting. [0003] Such as figure 1 As shown, the existing LED thyristor dimming circuits are all developed based on the switch circuit principle. Because the circuit needs to be compati...

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Problems solved by technology

Because the circuit needs to be compatible with the dimmer, the number of components is relatively large; especially the switching circuit will generate relatively large electromagnetic interference, and the original components L1, L2, CX1, and C3 are required to achieve attenuation to ensure that the power supply complies with EMC (electromagneticcompatibility electromagnetic compatibility) ) requirements, so that the power supply cost cannot be reduced, and the volume cannot be made small, which cannot meet the needs of production and market, and is not conducive to the miniaturization design of LED lamps

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