Control circuit of metal halide headlamp of digitized locomotive

Abstract

The invention relates to a control circuit of a front metal halide headlamp, in particular to a control circuit of a metal halide headlamp of a digitized locomotive, which mainly consists of the following five parts: an input circuit carries out rectification filtering on input voltage and inhibits an electromagnetic wave; an APFC grade outputs 400V DC voltage as the input voltage of the DC / DC-grade; a DC / DC grade carries out power processing; a DC / AC grade changes DC into AC, the drive of an IGBT tube thereof is realized by outputting a low-frequency sweeping square wave with 50% of a fixed duty ratio through the I / O port of a single-chip microprocessor; a secondary trigger is used for generating a high pressure to start up an HID lamp; and a digital controller is used for realizing voltage, current and power control and abnormal condition protection. The control circuit can achieve the cold-hot startup of a lamp tube, adopts the working mode of utilizing low-frequency to sweep square wave, avoids the acoustical resonance phenomena of a metal halide, and realizes matching of different load characteristics in different stages of ballasts and the lamp.

Description

technical field [0001] The invention relates to a control circuit for a front metal halide lamp, in particular to a digitalized locomotive metal halide headlamp control circuit. Background technique [0002] With the rapid development of the national economy, the rail transit industry and technology continue to develop, and the main railway lines, high-speed railways, intercity railways, local railways, and underground railways are growing rapidly. The safety and comfort requirements are getting higher and higher. Due to the gradual formation of a safe and fast railway network, railway trains will become the preferred means of travel for people. Therefore, safe and reliable railway products will be the responsibility of those who develop them. [0003] At present, most railway locomotive headlights use tungsten-halogen lamps, and some locomotives still use mercury-xenon lamps. In the early 1980s, mercury-xenon lamps were welcomed by locomotive staff for their advantages o...

AI Technical Summary

Problems solved by technology

However, due to the complex start-up process and timing control requirements, the existing metal halide lamp control circuit is often cumbersome and complicated, and it is easy to produce acoustic resonance phenomenon when working at high frequency, making the arc of the lamp unstable, the light flickering, or even extinguished. In severe cases, it will damage the discharge tube and greatly damage the life of the lamp

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