Ballast of random noise and sawtooth wave composite frequency modulation for gold halogen lamp

Abstract

This invention relates to a metal-halogen lamp ballast with the frequency modulated compositely by random noise and saw-tooth wave including an EMI, a primary supply commutation circuit, APFC and a DC supply, a self oscillation pulse generator, a half or total bridge driver, a half or total bridge switch inverter and a start up circuit of a control circuit characterizing in also including a random noise generator, a saw wave generator and an abnormal test protection circuit, in which, the double property of the rough tune of periodically changed saw-tooth wave and the fine tune of random noise disturbance changes around the central frequency to suppress the lamp discharging arcs to be unable to form stationary waves to avoid sound resonance and floating arc.

Description

technical field [0001] The invention relates to the technical field of energy-saving electric light sources for high-intensity gas discharge HID metal halide lamps, in particular to a ballast for metal halide lamps with compound frequency modulation of random noise and sawtooth waves. Background technique [0002] Metal halide lamps are a kind of high-intensity gas discharge HID lamps. Since the halide salts (such as sodium iodide, thallium, and scandium) in metal halide lamps can fully concentrate metal atoms during vaporization, compared with mercury lamps, they can The spectral color lines in the red and yellow areas will increase, the light color is better, close to the light of incandescent lamps, and the luminous efficacy reaches 80-125lm / w, which is higher than incandescent lamps, mercury lamps, and fluorescent lamps, becoming "green lighting". It can be widely used for lighting in shopping malls, supermarkets, hotels, restaurants, exhibition halls...

AI Technical Summary

Problems solved by technology

In the prior art, a single-frequency periodic signal is used as a frequency-modulated high-frequency pulse oscillator to make the pulse oscillation change according to the frequency-modulated signal to suppress the formation of standing waves of the same frequency in the lamp arc tube. Due to the large and fast periodic changes of the frequency-modulated signal, the light shakes or even extinguishes instantly. There are also occurrences, so the frequency modulation signal rate is limited by it, and increasing the pulse oscillation frequency will increase the power consumption of the circuit. When using a low-frequency square wave power supply to work, when the metal halide lamp is ignited horizontally, the arc will float upwards and approach the lamp tube, causing the temperature rise of the tube wall , the quartz tube turns white and burns out the lamp tube, so the technology of suppressing the sound resonance of metal halide lamps needs to be deepened and improved.

In addition, the triggering and starting process of the metal halide lamp is easy to cause damage to the lamp tube and the ballast. This is due to the high density of the discharge current, the large impact force, the instability of the gas discharge arc, and the lack of constant power characteristics of the power supply.

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