Reverse-excitation power supply

Abstract

Inverse excitation type power supply includes two transformers, voltage regulator tubes and capacitor. Positive pole of output end of each transformer is connected to a parallel circuit composed of two voltage regulator tubes and one capacitor. Main windings of two transformers are connected in series, and secondary windings of two transformers are connected in parallel. The said structure lowers own temperature of voltage regulator tubes and transformers, raises efficiency and reliability of power supply, and provides higher output power. The disclosed power supply is applicable to liquid crystal TV in large size.

Description

technical field [0001] The invention relates to a flyback power supply which can be used for a large-size liquid crystal television. Background technique [0002] After the appearance of LCD TVs, due to the increase in market demand and the development of technology, the power supply of LCD TVs has developed from the previous external power supply to the current built-in power supply. Due to the volume structure, the size of the power supply can only be made very small. Therefore, many problems have arisen, such as height, heat dissipation, power capacity, efficiency, etc., which have put forward new requirements for the power supply. [0003] The power supply of the TV has developed from the self-excited power supply used on the earliest CRT to the current flyback, forward, half-bridge, full-bridge, active clamp and other topologies. Although there are more and more topological structures of the power supply, the efficiency is getting higher and lower, and the temperature...

AI Technical Summary

Problems solved by technology

Although there are more and more topological structures of the power supply, the efficiency is getting higher and lower, and the temperature rise is getting lower and lower, but they all have certain limitations and disadvantages: due to the influence of the transformer, the flyback power supply can only Achieve 200W; the output of the forward power supply needs to be connected to an energy storage inductor, which will increase the weight of the power supply board, and the shock resistance of the power supply will also be affected to a certain extent; although half-bridge or full-bridge power supplies have appeared in recent years The latest topology, but because its leakage inductance is difficult to control, it is more difficult to produce; because the active clamp power supply is a foreign patented technology, it is more expensive to use

The flyback power supply is used more and more in modern TVs (CRT), but its efficiency is relatively low; if a quasi-resonant structure is used, its efficiency is improved, but it is still troubled by temperature rise and power; flyback The temperature rise, efficiency, output power and many other issues of the traditional power supply have become the issues that manufacturers are more concerned about.

The output power of the flyback power supply, without PFC, the maximum power that a PQ3230 magnetic core can achieve is only about 120W, and in the case of PFC, it can only reach about 180W at most, and now Most of the 32-inch LCD TV power supply needs to be around 230W, so the current flyback power supply cannot provide a reliable power supply for large-size LCD TVs

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