Novel AC voltage detection protection circuit and method

Abstract

The invention relates to a novel AC voltage detection protection circuit, which comprises a switching power supply circuit, a protection circuit and a control circuit, wherein the switching power supply circuit is provided with an input end connected with an AC power grid; the protection circuit comprises a processing module and a power supply module; the switching power supply circuit outputs a first voltage value and sends the first voltage value to the processing module; the processing module processes the first voltage value to obtain a second voltage value; the second voltage value is compared with a preset voltage value to judge whether to drive the power supply module to operate or not; and when the second voltage value is greater than the preset voltage value, the power supply module is not conducted so as not to supply power to the switching power supply circuit, and meanwhile, the control circuit reads the conduction state of the power supply module and judges whether to execute a protection action or not according to the conduction state of the power supply module so as to protect the switching power supply circuit. The system is simple in structure, and has the characteristics of full isolation, low cost, high reliability and high expandability.

Description

technical field [0001] The invention relates to a novel AC voltage detection and protection circuit and method. Background technique [0002] The AC voltage detection and protection circuit is composed of a voltage acquisition circuit, a comparison circuit or an A / D conversion circuit, and an execution circuit, which often cannot take into account both performance and cost; low-cost AC voltage detection and protection circuits are generally executive circuits and The acquisition circuit cannot be completely electrically isolated, and the circuit itself is not resistant to high voltage, so the safety factor is low; and the AC voltage detection and protection circuit with excellent performance often uses voltage transformers, high-precision operational amplifiers, and high-quality power supply voltages. , resulting in high costs. In the existing AC voltage detection and protection circuit, in order to realize the measurement of the AC voltage, the necessary steps are: step-do...

AI Technical Summary

Problems solved by technology

There are many steps in the whole process, and the corresponding steps will require corresponding circuit processing. The cost is high, the circuit is complicated, the failure rate is high, and the maintenance is complicated.

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