Single chip controlled power supply apparatus

Abstract

The invention discloses a power device controlled by a single chip. The power device comprises an AC input circuit, a filter network circuit, a rectifier bridge circuit, a flyback topology circuit, a main output circuit, a feedback network circuit, a control IC circuit, a slave output circuit and a compensation network circuit, where the input of the slave output circuit is connected with a central tap of an output winding of a transformer of the flyback topology circuit; and the compensation network circuit is connected between the main output circuit and the slave output circuit. By using the central tap of the output winding of the transformer as the main output, the power device can achieve relatively stable slave output voltage by fully utilizing the stability characteristic of the main output voltage, thereby simplifying the design and the debugging of the entire power device, lowering the cost and improving the circuit stability. With the aid of the compensation network circuit, the power device can still stabilize the slave output voltage in an allowable range under the condition of unloaded main output and loaded slave output.

Description

technical field [0001] The invention relates to a power supply device, in particular to a single-chip controlled power supply device. Background technique [0002] Since most electronic equipment (such as televisions, stereos, computers, etc.) use DC power for their internal components, it is necessary to have a power supply device to convert AC mains power into various DC voltages to enable electrical appliances to function . For the power solution controlled by a single chip, since the chip generally has only one voltage feedback terminal, it can strictly ensure the stability of the main output voltage under different load conditions, but cannot strictly stabilize the slave output. The single-chip power supply solution in the prior art has many methods for the stability of the slave output. The general method is to use a separate winding in the transformer to supply power for the slave output. The wave requirement is not high, but when the output load increases to a cert...

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Problems solved by technology

For the single-chip control power supply solution, since the chip generally only has one voltage feedback terminal, it can strictly ensure the stability of the main output voltage under different load conditions, but cannot strictly stabilize the slave output.

The single-chip power supply solution in the prior art has many methods for the stability of the slave output. The general method is to use a separate winding in the transformer to supply power for the slave output. The wave requirement is not high, but when the output load increases to a certain extent, it is necessary to add a complex voltage regulator circuit to keep the voltage fluctuating within the allowable range during circuit design, resulting in the disadvantages of difficult design and long debugging time

Another method is to use two-way stabilization to switch the feedback signal between the slave output and the main output voltage. When the slave output voltage is mainly used, the feedback signal is connected to the slave output to stabilize the slave output; otherwise, in When the main output voltage is mainly used, the feedback signal is connected to the main output to stabilize the main output; but this cannot achieve simultaneous stabilization of the main output and the slave output, resulting in one of the output voltages stabilizing, and the other output voltage will be Disadvantages of large fluctuations

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