Reverse connection prevention overvoltage protection circuit

Abstract

The utility model provides an anti-reverse connection overvoltage protection circuit, which comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a triode Q2, an MOS tube Q1 and an MOS tube Q3, one end of the resistor R1 is connected with the resistor R2 and the resistor R4, the source electrode of the MOS tube Q3 and input voltage are used for transmitting of the triode Q2, the other end of the resistor R1 is connected with the grid electrode of the MOS tube Q1, the other end of the resistor R2 is connected with the resistor R3 and the cathode of a diode D1, and the other end of the diode D1 is connected with the resistor R2 and the anode of the diode D1. The design circuit solves the problem that an unmatched power adapter is used or a reverse power supply is plugged by mistake, equipment damage is not caused, and the safety of the equipment is improved.

Description

Technical Field

[0001] The utility model relates to the field of circuit control, in particular to an anti-reverse connection overvoltage protection circuit. Background Art

[0002] With the development of electronic technology and the improvement of people's quality of life, the safety requirements for the use of electronic products are getting higher and higher. Many power adapters on the market have the same output voltage interface but different output voltages. If a power supply with a high output voltage is connected to a low-voltage device or the positive and negative poles of the power supply are connected in reverse, it will cause the product to be damaged and unusable, increase the amount of electronic waste in the environment, and in serious cases, it will burn out and cause a fire. Utility Model Content

[0003] In order to make up for the deficiencies of the prior art, the embodiments of the present application solve the problem of using an incompatible power adapter or mistakenly plugging in the wrong power source without causing damage to the device, thereby increasing the safety of the device.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A reverse connection overvoltage protection circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a transistor Q2, a MOS transistor Q1, and a MOS transistor Q3. One end of the resistor R1 is connected to the resistor R2, the resistor R4, the emitter of the transistor Q2, the source of the MOS transistor Q3, and an input voltage. The other end of the resistor R1 is connected to the gate of the MOS transistor Q1. The other end of the resistor R2 is connected to the resistor R3 and the cathode of the diode D1. The other end of the resistor R3 is connected to the base of the transistor Q2. The collector of the transistor Q2 is connected to the resistor R4, the resistor R5, and the gate of the MOS transistor Q3. The source of the MOS transistor Q1 is connected to the anode of the diode D1, the other end of the resistor R5, and the output voltage. The drain of the MOS transistor Q3 is connected to the other end of the output voltage.

[0006] As a further technical solution of the present invention: the transistor Q2 is a PNP transistor.

[0007] As a further technical solution of the present invention: the MOS tube Q1 is an N-MOS tube.

[0008] As a further technical solution of the present invention: the MOS tube Q3 is an N-MOS tube.

[0009] As a further technical solution of the present invention: the diode D1 is a voltage-stabilizing diode.

[0010] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0011] 1. Design a low-cost overvoltage protection circuit using a small number of basic components.

[0012] 2. Improve product safety and reduce electronic waste in the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of an overvoltage protection circuit provided by an embodiment of the present utility model;

[0014] Figure 2 This is a flow chart of an overvoltage protection circuit provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0016] Reference Figure 1 A reverse connection overvoltage protection circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a transistor Q2, a MOS transistor Q1, and a MOS transistor Q3. One end of the resistor R1 is connected to the resistor R2, the resistor R4, the emitter of the transistor Q2, the source of the MOS transistor Q3, and an input voltage. The other end of the resistor R1 is connected to the gate of the MOS transistor Q1. The other end of the resistor R2 is connected to the resistor R3 and the cathode of the diode D1. The other end of the resistor R3 is connected to the base of the transistor Q2. The collector of the transistor Q2 is connected to the resistor R4, the resistor R5, and the gate of the MOS transistor Q3. The source of the MOS transistor Q1 is connected to the anode of the diode D1, the other end of the resistor R5, and the output voltage. The drain of the MOS transistor Q3 is connected to the other end of the output voltage.

[0017] Transistor Q2 is a PNP transistor. MOS transistor Q1 is an N-MOS transistor. MOS transistor Q3 is an N-MOS transistor. Diode D1 is a Zener diode.

[0018] Here’s how it works:

[0019] Figure 2 This is a flow chart of an anti-reverse connection overvoltage protection circuit provided by an embodiment of the utility model, which implements the logic:

[0020] Step 1: Connect voltage;

[0021] Step 2: If the input voltage is connected correctly, go to step 3. If it is connected incorrectly, go to step 5.

[0022] Step 3: If the input voltage is less than the voltage regulation value of the Zener diode D1, skip to step 4; otherwise, skip to step 6.

[0023] Step 4: The voltage regulator D1 is turned off, and then Q2 is turned off, causing Q3 to turn on, and there is voltage output, jumping to step 7;

[0024] Step 5: Q1 is cut off, no voltage is output, jump to step 7;

[0025] Step 6: The voltage regulator D1 is turned on, and Q1 is turned on, causing Q3 to be cut off, with no voltage output, and skipping to step 7;

[0026] Step 7: End.

[0027] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced within the present invention.

[0028] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment have also been appropriately combined to form other implementation methods that are easy for those skilled in the art to understand.

Claims

1. A reverse connection overvoltage protection circuit, comprising a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a transistor Q2, a MOS transistor Q1, and a MOS transistor Q3, characterized in that: One end of the resistor R1 is connected to the resistor R2, the resistor R4, the emitter of the transistor Q2, the source of the MOS transistor Q3, and the input voltage; the other end of the resistor R1 is connected to the gate of the MOS transistor Q1; the other end of the resistor R2 is connected to the resistor R3 and the cathode of the diode D1; the other end of the resistor R3 is connected to the base of the transistor Q2; the collector of the transistor Q2 is connected to the resistor R4, the resistor R5, and the gate of the MOS transistor Q3; the source of the MOS transistor Q1 is connected to the anode of the diode D1, the other end of the resistor R5, and the output voltage; and the drain of the MOS transistor Q3 is connected to the other end of the output voltage.

2. The anti-reverse connection overvoltage protection circuit according to claim 1, characterized in that: The transistor Q2 is a PNP transistor.

3. The anti-reverse connection overvoltage protection circuit according to claim 1, characterized in that: The MOS transistor Q1 is an N-MOS transistor.

4. The anti-reverse connection overvoltage protection circuit according to claim 1, characterized in that: The MOS transistor Q3 is an N-MOS transistor.

5. The anti-reverse connection overvoltage protection circuit according to claim 4, characterized in that: The diode D1 is a voltage stabilizing diode.

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