Power supply polarity protection circuit

Abstract

A power supply polarity protection circuit comprises a first input terminal, a second input terminal, an electronic switch, a relay, a positive output terminal and a negative output terminal; wherein, the relay is provided a first normally open contact, a second normally open contact, a first normally closed contact and a second normally closed contact; the first input terminal and the second input terminal are respectively connected with an anode and a cathode of a DC power supply; a first terminal and a second terminal of the electronic switch are respectively connected with the first input terminal and the second input terminal; a third terminal of the electronic switch is connected with the first input terminal via the relay; the first input terminal and the second input terminal are respectively connected with the positive output terminal and the negative output terminal via the first normally open contact and the second normally open contact, and are also respectively connected with the negative output terminal and the positive output terminal via the first normally closed contact and the second normally closed contact; the positive output terminal and the negative output terminal are respectively communicated with the first input terminal and the second input terminal via the first normally closed contact and the second normally closed contact or via the first normally open contact and the second normally open contact to output correct polarity. The power supply polarity protection circuit is simple in structure.

Description

technical field [0001] The invention relates to a power supply polarity protection circuit. Background technique [0002] When electronic equipment is powered by an external DC power supply, the polarity of its input must be the same as that of the output terminal of the external DC power supply in order to be able to work effectively and safely. When the operator connects the electronic equipment to the external power supply, sometimes the The positive and negative power input terminals of the electronic equipment and the positive and negative output terminals of the external power supply are reversely connected, which may cause the electronic equipment to not work normally, or cause the equipment to burn out, or even a major accident, resulting in irreparable losses. Contents of the invention [0003] In view of the above, it is necessary to provide a power supply polarity protection circuit to protect electronic equipment from being damaged when the polarity of the exte...

AI Technical Summary

Problems solved by technology

[0002] When electronic equipment is powered by an external DC power supply, the polarity of its input must be the same as that of the output terminal of the external DC power supply in order to be able to work effectively and safely. When the operator connects the electronic equipment to the external power supply, sometimes the The positive and negative power input terminals of the electronic equipment are reversely connected with the positive and negative output terminals of the external power supply, which may cause the electronic equipment to not work normally, or cause the equipment to burn out, or even a major accident, resulting in irreparable losses.

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