AC overvoltage protection device

Abstract

The invention belongs to the technical field of electric apparatuses, more particularly discloses an AC overvoltage protection device. The AC overvoltage protection device consists of a power circuit, a voltage detection and comparison control circuit connected with the power circuit, and a micro control unit (MCU) which is connected with the power circuit and based on an external memory or a built-in memory and has a clock sensing function. An output terminal of the voltage detection and comparison control circuit is connected with the MCU which is connected with various loops of a protected electrical apparatus. The AC overvoltage protection device has the advantages of stable supply voltage and high voltage resistance, can ensure operating correctness and stability of the device, has wide high-voltage protection scope and can better perform timely protection in the event of abnormal voltage. In addition, as the AC overvoltage protection device has simple structure and small size, the device can be directly designed on a circuit board, mass production can be realized without modifying procedures, and the manufacturing cost is low.

Description

technical field [0001] The invention relates to an overvoltage protection device, in particular to an AC overvoltage protection device applied in the technical field of electrical appliances. Background technique [0002] At present, in the field of air-conditioning product technology, when the external input AC voltage is abnormal, it is necessary to add an overvoltage protection device to protect the normal operation of the entire electrical circuit. It also needs to be protected, so the high-voltage withstand voltage range of the transformer is reduced, that is, the high-voltage protection range of the protection device is reduced. The overall volume of the transformer is larger, which makes the entire overvoltage protection device larger, and a special space needs to be set up. In addition, the comparison circuit used in the existing protection device includes a variety of components such as voltage regulator IC, the circuit is complex, the failure rate is high, and the ...

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Problems solved by technology

[0002] At present, in the field of air-conditioning product technology, when the external input AC voltage is abnormal, it is necessary to add an overvoltage protection device to protect the normal operation of the entire electrical circuit. It also needs to be protected, so the high-voltage withstand voltage range of the transformer is reduced, that is, the high-voltage protection range of the protection device is reduced. The overall volume of the transformer is larger, which makes the entire overvoltage protection device larger, and a special space needs to be set up. In addition, the comparison circuit used in the existing protection device includes a variety of components such as voltage regulator IC, the circuit is complex, the failure rate is high, and the maintenance cost is high

[0003] In addition, the existing sources of the power source of the overvoltage protection device itself are divided into the following types: The first type: the power source of the protection device itself is directly obtained from the mains through the voltage divider resistor. The problem with this method is that the protection If the power supply voltage of the device itself is unstable, it will inevitably affect the voltage of the entire air-conditioning power supply circuit; the second type: the power supply of the protection device is obtained from the battery installed by itself, and the power supply of this protection method needs to be obtained separately, and battery replacement is troublesome. And with the increase of time, the voltage of the battery will drop, and its service life is also limited

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