Low-cost power supply reverse connection protection circuit

Abstract

The invention discloses a low-cost power supply reverse connection protection circuit, which is characterized in that the positive electrode of a power supply in the circuit is connected with a sourceelectrode of Q1 and an anode of D2, a drain electrode of Q1 is connected with a cathode of D2, an anode of D3, one end of R1 and an anode power supply end of a square wave generator, and a grid electrode of Q1 is connected with one end of C3 and a cathode of D6; the cathode of D3 is connected with one end of C7 and the anode of D4, the cathode of D4 is connected with the anode of D5 and one end of C4, the cathode of D5 is connected with one end of C6 and the anode of D6, and the other end of R1 is connected with the other end of C7, the other end of C6 and a collector electrode of Q2; and thenegative electrode of the power supply is connected with the other end of C3, the other end of C4, an emitting electrode of Q2, a grounding end GND and a negative electrode power supply end of the square wave generator. The circuit is low in cost and high in reliability, automatic reverse connection protection is achieved without depending on an MCU and software programs of the MCU, and industrial mass production and application are facilitated.

Description

technical field [0001] The invention belongs to the technical field of circuit design of automobile power supply, and relates to a low-cost power reverse connection protection circuit. Background technique [0002] With the development of the automobile industry, various controllers are more and more widely used in automobiles, and the self-protection function of the controller is also getting higher and higher. Anti-power reverse connection is one of the self-protection functions of electronic products; power reverse connection It will cause permanent damage to the controller, so it is necessary to add a protection circuit to the controller circuit to achieve the purpose of not being damaged even if the reverse power is connected. [0003] In the prior art, it is generally possible to connect a diode in series at the positive pole of the power supply. However, due to the voltage drop of the diode, it will cause unnecessary losses to the circuit and greatly reduce the operat...

AI Technical Summary

Problems solved by technology

Therefore, the power supply reverse connection protection of this circuit needs to rely on the more expensive MCU chip, AD conversion device and PWM signal generation module, and the cost is still high. Complex and not reliable enough, not convenient for industrial mass production and application

[0006] Based on this, it is urgent to design a low-cost power reverse connection protection circuit to overcome the high cost defect of the automotive power reverse connection protection circuit in the prior art, and to facilitate industrial mass production and application

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