Power polar protective circuit

Abstract

The invention relates to a power polar protective circuit, which comprises a first input end, a second input end, a comparison amplifier, a first electronic switch, a second electronic switch, a third electronic switch, a fourth electronic switch, a positive output end and a negative output end. A positive input end and a reverse input end of the comparison amplifier are connected to the first input end and the second input end respectively; when the first input end and the second input end are connected with a positive electrode and a negative electrode of a DC power supply respectively, the first electronic switch and the second electronic switch are conducted, and the positive output end and the negative output end are communicated with the first input end and the second input end respectively; and when the first input end and the second input end are connected with the negative electrode and the positive electrode of the DC power supply respectively, the positive output end and the negative output end are communicated with the second input end and the first input end through the fourth electronic switch and the third electronic switch, so that a correct polar is output. The power polar protective circuit has a simple 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...

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