Multi-frequency oscillator applied to electronic ballast

Abstract

The invention discloses a multi-frequency oscillator applied to an electronic ballast, which mainly solves the problems that a fluorescent lamp has no preheating or ignition and has short service life. The multi-frequency oscillator of the invention comprises a reference current generating circuit, a voltage control circuit, a current control circuit, a current mirror circuit and an oscillating signal generating circuit, wherein the current control circuit is connected between the reference current generating circuit and the current mirror circuit to generate charge / discharge current in a functional relationship with reference current and voltage control output voltage so that the oscillator works in different frequencies; the voltage control circuit is connected on the output of the current control circuit; and the current control circuit is controlled by the output of the voltage control circuit so as to realize adjustment of different frequency time of the oscillator and finish preheating, ignition and normal light emission of the fluorescent lamp. The multi-frequency oscillator can prolong the service life of the fluorescent lamp, and can be widely applied to the electronic ballast of the fluorescent lamp.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and relates to an analog integrated circuit, in particular to a frequency oscillator, which can be used in an electronic ballast for fluorescent lamps. Background technique [0002] Multi-frequency oscillators are widely used in electronic ballasts of fluorescent lamps, and can complete the preheating, start-up and normal lighting of fluorescent lamps by changing their frequencies in different time periods. According to the characteristics of the preheating fluorescent lamp, its normal operation needs to have three working stages: 1. Give a large current to the filament for preheating within a certain period of time; 2. Give the lamp a high enough starting voltage for ignition in a short period of time 3. Finally, make the lamp work normally under rated power. When the lamp circuit is at the preheat frequency f ph Preheat when the frequency is gradually reduced and approach the natu...

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Problems solved by technology

[0004] It can be seen that, because the above-mentioned existing oscillator charge and discharge current is constant, the frequency of the oscillator is fixed, and the preheating and ignition of the fluorescent lamp cannot be completed, resulting in shortened life of the fluorescent lamp.

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