An input circuit for anti-reverse polarity protection

Abstract

The invention discloses an anti-reverse connection input circuit and a DC input device. The input circuit comprises: the first input end of the input circuit is connected to the first output end of the input circuit through a first switch; the first diode and the second A switch is connected in parallel; the second input end of the input circuit is connected to the second output end of the input circuit; the first input end and the second input end of the voltage detection unit are respectively connected to the first output end and the second output end of the input circuit; The voltage detection unit is used for: detecting whether there is a voltage between the two output terminals of the input circuit, and controlling the closing and opening of the first switch according to the detection result. The input circuit can improve the electric energy utilization efficiency of the DC input equipment, and can effectively protect the reverse polarity of the power supply of the DC input equipment for a long time.

Description

technical field [0001] The invention relates to anti-reverse connection technology, in particular to an input circuit for anti-reverse connection protection. Background technique [0002] Inside the DC input device, in order to prevent the polarity of the power supply connected to the two input terminals of the DC input device from being reversed, causing damage to the components or lines of the DC input device, a Diodes to protect DC input devices by utilizing the single-phase conductivity of diodes. [0003] figure 1 It is a schematic diagram of the input circuit structure of a DC input device in the prior art, such as figure 1 As shown, the input circuit includes: the first input end of the input circuit is connected to the first output end of the input circuit through the first diode D1 and the first switch K1 connected in series; the second input end of the input circuit is connected to the The second output terminal, and the two input terminals of the voltage detect...

AI Technical Summary

Problems solved by technology

[0006] But when figure 1 In the shown DC charging circuit, since the first diode D1 is connected to the branch of the main circuit, when the DC input device works normally, there will be current flowing through the first diode D1, so that the first diode D1 will Cause continuous energy loss, especially when the current flowing through the branch of the main circuit is large, this energy loss will be greater, thereby reducing the power utilization efficiency of the DC input device; while in figure 2 In the DC charging circuit shown, although the reverse polarity protection of the power supply can be realized through the first diode D1, if the polarity of the power supply is reversed for a long time, the electric energy of the power supply will be added to the first resistor R1 for a long time. There is continuous energy loss on the first resistor, which may cause damage to the first resistor R1 and even the circuit. Therefore, figure 2 The DC charging circuit shown cannot be protected against reverse polarity of the power supply for a long time

[0007] In the above two circuits, the first diode may have a long-term current passing through it, resulting in continuous loss, and there are higher requirements for its type selection and heat dissipation requirements, which will inevitably increase the volume and cost.

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