Method and device for fluorescent lamp two-wire system dimming control

Abstract

The invention relates to a method and a device for fluorescent lamp two-wire system dimming control. A user end microprocessor receives a user request signal to ensure that the change in a circuit is impeded, thereby a large chamfer voltage waveform signal is formed on an alternating wire within a period of time and forms a dimming control signal after being subjected to waveform conversion of an electronic ballast and signal detection processing. The device is formed by connecting a user control end and an electronic ballast end through alternating current wires. The user control end comprises a dimming control signal input circuit, an impedance switching circuit and a bidirectional control silicon circuit; and the electronic ballast end comprises a rectifying circuit, a power factor correction circuit and an inverter circuit which are sequentially connected, and a waveform conversion circuit, a waveform recognition and digital/analogue conversion circuit and a lower-pass filter circuit. The invention forms the large chamfer voltage waveform signal only in short time for regulation and control operation and only maintains a smaller initial chamfer in other time, therefore, the power factor of the ballast can be maintained above 0.95 and the total current harmonic distortion can be improved to be less than 20 percent.

Description

【Technical field】 [0001] The patent of the invention relates to the dimming control technology of fluorescent lamps with electronic ballasts, in particular to a two-wire dimming control method for fluorescent lamps and a bidirectional thyristor dimming control device. 【Background technique】 [0002] At present, among the light sources for indoor lighting, incandescent lamps have been gradually eliminated due to their low luminous efficiency, high power consumption, and short lifespan. With the development of new materials, new structures, new design theories and manufacturing processes, the comprehensive performance of fluorescent lamps has been greatly improved. With the continuous development of energy-saving and high-efficiency technical advantages, fluorescent lamps have become the main light source for architectural lighting. [0003] Electronic ballasts for dimmable fluorescent lamps have obvious power-saving effects, and have been rapidly developed and applied in rec...

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Problems solved by technology

[0008] The technical problem to be solved by the present invention is to overcome the large total current harmonic distortion caused by the input voltage waveform always maintaining a certain large cutting angle during the operation of the electronic ballast in the traditional thyristor phase control dimming method. The defect is to provide a two-wire dimming control method for fluorescent lamps and a bidirectional thyristor dimming control device corresponding to the dimming control method

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