Mains supply voltage detection circuit and switching power supply system using same

Abstract

The invention discloses a mains supply voltage detection circuit and a switching power supply system using the same. The whole circuit is electrically connected with external AC input through a diode,and the circuit is composed of a mains supply voltage conversion circuit, a carrier wave generation circuit and a modulation circuit; the mains supply voltage conversion circuit and the carrier wavegeneration circuit are arranged in parallel, and the input ends of the mains supply voltage conversion circuit and the carrier wave generation circuit are electrically connected and jointly serve as the input end of the whole mains supply voltage detection circuit. The output ends of the mains supply voltage conversion circuit and the carrier wave generation circuit are electrically connected withthe input end of the modulation circuit. The output end of the modulation circuit is used as the output end of the whole mains supply voltage detection circuit. The system is excellent in use effectand simple and visual in structure, and the setting cost is greatly reduced while the use effect is improved.

Description

technical field [0001] The invention relates to a detection circuit and a switching power supply using the circuit, in particular to a commercial voltage detection circuit and a switching power supply system using the circuit, belonging to the technical field of power semiconductors. Background technique [0002] Switching power supply, as the structural basis of various electrical mechanisms and devices, is widely used. In addition, in recent years, with the continuous development and improvement of electronic power technology and industrial manufacturing level, switching power supply technology has also made great progress. [0003] Taking the mains voltage detection circuit common in various electrical mechanisms and devices as an example, this type of circuit is mainly used to detect the power frequency power supply, so as to achieve the purpose of adjusting the output power of the system to match the current input voltage of the mains . [0004] In the prior art, an i...

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Problems solved by technology

At the same time, since the transformer transmits an analog voltage signal, after this type of signal is input into the single-chip microcomputer, it needs to occupy its internal resources to convert the analog signal into a digital signal for subsequent processing

[0006] To sum up, although the above-mentioned current scheme can realize a certain function of mains voltage detection, the transformer used in it is large in size and high in cost. Contrary to the miniaturization development trend of the system as a whole, and in this solution, the system occupies more resources, the solution cost is high, and the reliability is low

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