Light-adjusting circuit for electrodeless florescent lamp

Abstract

The invention discloses the dimming circuit of an electrodeless fluorescent lamp. The dimming circuit is connected with an electrodeless fluorescent lamp circuit. The electrodeless fluorescent lamp circuit comprises an active power factor corrector, a central processing unit, an electromagnetic inductor and a power take-off at least. The dimming circuit comprises a sawtooth generator used for generating sawtooth, a potentiometer having an adjustable resistance value and a voltage comparator which is connected with the potentiometer and also connected with the sawtooth generator. The potentiometer adjusts the resistance value to produce an adjustable voltage, and the voltage comparator compares the adjustable voltage with the sawtooth generated by the sawtooth generator to generate a square signal that changes linearly. The dimming circuit also comprises an optoelectronic isolator which is connected with the voltage comparator and also connected with the central processing unit and receives the square signal produced by the voltage comparator to produce a PWM signal so as to concoct the central processing unit. The dimming circuit increases the function of monitoring running conditions of a strip lamp and performing real-time protection and prolongs the service life.

Description

technical field [0001] The invention relates to an electrodeless fluorescent lamp circuit, in particular to a dimming circuit for pulse width modulation of an electrodeless fluorescent lamp. Background technique [0002] Electrodeless fluorescent lamps are a new generation of energy-saving products with no filament, high luminous efficiency, long life, and high power factor. They are widely used, especially in places where the lamp tube is not suitable for replacement. Since the electrodeless fluorescent lamp is started and ignited without electrodes, there is no phenomenon that the whole lamp will be scrapped due to the damage of the filament or the exhaustion of the electron powder emission and the blackening of the lamp tube due to the sputtering of the electron powder, and the life of the whole lamp is greatly extended. And the working frequency exceeds 250KHz, which can eliminate the stroboscopic phenomenon. However, the circuit design of the electrodeless fluorescent ...

AI Technical Summary

Problems solved by technology

When dimming, the power of the lamp changes with the oscillation frequency of the chip, and the dimming range is small (50% dimming), and there are phenomena such as self-extinguishing of the lamp and failure to start at low power

At the same time, HY4501 is now used as a central processor with a single protection function, no output short circuit, empty magnetic ring and over-power protection functions, lack of accurate sampling and monitoring of the voltage and current of the electrodeless fluorescent lamp, and the electrodeless fluorescent lamp cannot be adjusted in time according to the real-time operating conditions working status

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