Reverse connection prevention circuit and battery charging reverse connection prevention method
By designing an anti-reverse circuit using discrete electronic devices, the problems of slow reaction, high cost and short device life in the prior art are solved, and fast and effective circuit shutdown and low-cost battery charging anti-reverse protection are achieved.
Patent Information
- Application Number
- CN202311453305.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-02
- Publication Date
- 2025-05-13
AI Technical Summary
In the existing 12V battery charging system, the reverse connection detection circuit controlled by integrated chip is slow, has high cost and has a short device life, which cannot effectively prevent short circuit accidents caused by wrong connection of positive and negative poles.
An anti-reverse circuit is designed to realize the charging recognition and shutdown function of external power supply through simple discrete electronic devices, including charging unit, detection unit, control unit, first switching unit and second switching unit, and components such as transistors and field effect tubes are used to quickly identify and disconnect error connections.
It realizes quick and efficient shutdown of wrong connections, reduces manufacturing costs, and accurate judgment results, and does not cause damage to electronic devices.
Smart Images
Figure CN119995067A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of battery charging, and in particular to an anti-reverse connection circuit and a battery charging anti-reverse connection method. Background Art
[0002] As an energy conversion device, the car battery needs to supply power when the car is at low speed or parked. In order to maintain the basic function or life of the battery, the battery needs to be recharged during long-term non-use or transportation. During the recharging process, it is easy to cause a short circuit accident when the positive and negative poles are connected incorrectly by bridging with other batteries or connecting an external charger, causing personal safety issues.
[0003] In the existing 12V battery charging system, an integrated chip is usually used to implement reverse connection detection to disconnect the circuit. The integrated chip analog input port detects the voltage range and current change range, performs logical judgment according to the set critical point, and outputs the judgment result to disconnect the circuit. There are the following problems with using an integrated chip to control the circuit: first, the circuit reacts slowly, because the integrated chip needs to perform logical judgment, signal comparison and circuit reaction take a long time; second, the manufacturing cost of the integrated chip is high; finally, the integrated chip has a certain probability of failure and the circuit is complex. There are other anti-reverse connection circuits in the prior art, such as a diode anti-reverse circuit, but the diode anti-reverse circuit can only be applied to a unidirectional conduction circuit, but the 12V battery charging system has two directions of charging and discharging, and cannot be used in this circuit; there is also a P-type MOS tube anti-reverse circuit, but the P-type MOS tube anti-reverse circuit is suitable for small current systems and cannot cope with overvoltage and overcurrent in the circuit. Summary of the invention
[0004] To solve the above problems, the present invention provides an anti-reverse connection circuit and a battery charging anti-reverse connection method, which realize external power supply charging identification and shutdown functions through simple discrete electronic devices, solve the problems of slow identification speed, high material cost and short device life in the prior art, and achieve the technical effect of fast and effective shutdown with low cost.
[0005] The present invention provides an anti-reverse connection circuit, comprising a charging unit, a detection unit, a control unit, a first switch unit and a second switch unit, wherein the charging unit comprises a battery, a port T30 and a port T31, wherein the port T30 corresponds to the positive electrode of the battery, and the port T31 corresponds to the negative electrode of the battery, and when the negative electrode of an external power source is connected to the port T30 and the positive electrode of the external power source is connected to the port T31, the detection unit and the control unit are both turned on, the first switch unit and the second switch unit are turned off, and the charging unit is turned off.
[0006] Preferably, the detection unit includes a transistor T1, a resistor R1, and a resistor R2.
[0007] Preferably, the base of the transistor T1 is connected to the first end of the resistor R1, the base of the transistor T1 is also connected to the first end of the resistor R2, the second end of the resistor R2 is connected to the emitter of the transistor T1, the emitter of the transistor T1 is connected to port T31, and the collector of the transistor T1 is connected to the first end of the resistor R3.
[0008] Preferably, the transistor T1 is a PNP transistor.
[0009] Preferably, the control unit includes a transistor T2, a resistor R3 and a resistor R4.
[0010] Preferably, the second end of the resistor R3 is connected to the base of the transistor T2, the second end of the resistor R3 is also connected to the first end of the resistor R4, and the second end of the resistor R4 is connected to the emitter of the transistor T2.
[0011] Preferably, the transistor T2 is an NPN transistor.
[0012] Preferably, the second switch unit includes a field effect transistor MOS2.
[0013] Preferably, the field effect transistor MOS2 is an N-type MOS transistor.
[0014] Preferably, the source of the field effect transistor MOS2 is connected to the emitter of the transistor T2, the drain of the field effect transistor MOS2 is connected to the drain of the field effect transistor MOS1, the gate of the field effect transistor MOS2 is connected to the first end of the resistor R7, and the second end of the resistor R7 is connected to the emitter of the transistor T2.
[0015] Preferably, the second end of the resistor R7 is also connected in series with a resistor R8 , and the resistor R8 is connected to the driving signal 2 .
[0016] Preferably, the first switch unit includes the field effect transistor MOS1.
[0017] Preferably, the field effect transistor MOS1 is an N-type MOS transistor.
[0018] Preferably, the source of the field effect transistor MOS1 is connected to the port T31, the gate of the field effect transistor MOS1 is connected to the first end of the resistor R5, and the second end of the resistor R5 is connected to the port T31.
[0019] Preferably, the second end of the resistor R5 is also connected in series with a resistor R6, and the resistor R6 is connected to the drive signal 1.
[0020] Preferably, the anti-reverse connection circuit further includes a diode D1 , the second end of the resistor R1 is connected to the input end of the diode D1 , and the output end of the diode D1 is connected to the port T30 .
[0021] Preferably, a transient voltage regulator diode TVS2 is connected in series between the second end of the resistor R7 and the source of the field effect transistor MOS2.
[0022] Preferably, a transient voltage regulator diode TVS1 is connected in series between the second end of the resistor R5 and the source of the field effect transistor MOS1.
[0023] Preferably, when the positive electrode of the external power source is connected to the port T30 and the negative electrode of the external power source is connected to the port T31, the charging unit works normally.
[0024] The present invention also provides a battery charging reverse connection prevention method, which is applied to any of the above-mentioned reverse connection prevention circuits.
[0025] Compared with the prior art, the above technical solution has the following beneficial effects:
[0026] 1. Use simple electronic devices to identify the positive and negative poles of the external power supply. If the positive and negative poles of the external power supply are connected incorrectly, the circuit can be quickly shut down;
[0027] 2. Low manufacturing cost and simple circuit;
[0028] 3. The judgment results are accurate and will not cause damage to electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a flow chart of the anti-reverse connection system in the prior art;
[0030] Figure 2 A reverse connection protection circuit diagram according to an embodiment of the present invention;
[0031] Figure 3 FIG. 4 is a flow chart of a reverse connection protection circuit according to an embodiment of the present invention. DETAILED DESCRIPTION
[0032] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.
[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.
[0034] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.
[0035] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".
[0036] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.
[0037] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.
[0038] See also Figure 1 , is a flow chart of the reverse connection protection system in the prior art. In the battery charging circuit, the detection circuit and the integrated chip are required to judge the positive and negative poles of the external power supply. The detection circuit simulates the input port to detect the voltage range and current variation range. The integrated chip performs logical judgment according to the set critical point and outputs the judgment result and controls the switch to disconnect the circuit.
[0039] See also Figure 2-3 , is a reverse connection protection circuit diagram and a flow chart according to an embodiment of the present invention.
[0040] The invention discloses an anti-reverse connection circuit, which comprises a charging unit, a detection unit, a control unit, a first switch unit and a second switch unit.
[0041] The charging unit includes a battery, a port T30, and a port T31, wherein the port T30 corresponds to the positive electrode of the battery, and the port T31 corresponds to the negative electrode of the battery. When the positive and negative electrodes of the external power supply are connected correctly, the port T30 is connected to the positive electrode of the external power supply, and the port T31 is connected to the negative electrode of the external power supply, the detection unit and the control unit are not turned on, the charging unit works normally, and the external power supply can charge the battery normally; when the positive and negative electrodes of the external power supply are connected incorrectly, that is, the negative electrode of the external power supply is connected to the port T30, and the positive electrode of the external power supply is connected to the port T31, the detection unit and the control unit are both turned on, and the first switch unit and the second switch unit are disconnected, so the charging unit is disconnected, thereby achieving the function of protecting the battery from reverse connection.
[0042] The detection unit includes a transistor T1, a resistor R1, and a resistor R2, wherein the base of the transistor T1 is connected to the first end of the resistor R1, the base of the transistor T1 is also connected to the first end of the resistor R2, the second end of the resistor R2 is connected to the emitter of the transistor T1, the emitter of the transistor T1 is connected to the port T31, and the collector of the transistor T1 is connected to the first end of the resistor R3.
[0043] The transistor T1 is a PNP transistor. A PNP transistor is a transistor composed of two P-type semiconductors with one N-type semiconductor sandwiched between them, and current flows from the emitter to the collector. When the positive electrode of the external power supply is connected to the port T31, the resistor R1 and the resistor R2 are turned on instantly, and due to the voltage difference between the two ends of the resistor R2, the transistor T1 is turned on, that is, the detection unit is turned on.
[0044] The control unit includes a transistor T2, a resistor R3 and a resistor R4, wherein the second end of the resistor R3 is connected to the base of the transistor T2, the second end of the resistor R3 is also connected to the first end of the resistor R4, and the second end of the resistor R4 is connected to the emitter of the transistor T2.
[0045] The transistor T2 is an NPN transistor. An NPN transistor is a transistor composed of two N-type semiconductors with one P-type semiconductor sandwiched between them. Current flows in from the collector and the base and flows out from the emitter. Its main functions are current amplification and switching. After the detection unit is turned on, since the resistor R4 connects the emitter of the transistor T2 and the base of the transistor T2, the voltage difference between the two ends of the resistor R4 turns on the transistor T2, that is, the control unit is turned on.
[0046] The second switch unit includes a field effect transistor MOS2. The field effect transistor MOS2 is an N-type MOS transistor. A transistor with a metal-oxide-semiconductor structure is referred to as a MOS transistor. The N-type MOS transistor uses a low-doped P-type silicon material as a substrate, and manufactures two highly doped N-type regions on it. Two electrodes are led out respectively as a source and a drain. A very thin silicon dioxide insulating layer is covered on the surface of the P-type substrate, and an electrode is led out as a gate. The gate of this field effect transistor is insulated from the P-type semiconductor substrate, the drain and the source. When the voltage difference between the gate and the source is zero, that is, V GS = 0, there is no current flowing between the drain and the source, that is, I DS =0, the MOS tube is in the cut-off state. When V GS >V th When V th is the turn-on voltage, and current flows between the drain and source.
[0047] When the control unit is turned on, the gate of the field effect transistor MOS2 and the source of the field effect transistor MOS2 are short-circuited, and the field effect transistor MOS2 is turned off. The source of the field effect transistor MOS2 is connected to the emitter of the transistor T2, the drain of the field effect transistor MOS2 is connected to the drain of the field effect transistor MOS1, the gate of the field effect transistor MOS2 is connected to the first end of the resistor R7, and the second end of the resistor R7 is connected to the emitter of the transistor T2; the second end of the resistor R7 is also connected in series with the resistor R8, and the resistor R8 is connected to the drive signal 2.
[0048] The first switch unit includes a field effect transistor MOS1, which is also an N-type MOS transistor. The source of the field effect transistor MOS1 is connected to the port T31, the gate of the field effect transistor MOS1 is connected to the first end of the resistor R5, the second end of the resistor R5 is connected to the port T31, the gate of the field effect transistor MOS1 is connected to the first end of the resistor R5, and the second end of the resistor R5 is connected to the port T31; the second end of the resistor R5 is also connected in series with a resistor R6, and the resistor R6 is connected to the drive signal 1.
[0049] A transient voltage stabilizing diode TVS2 is also connected in series between the second end of the resistor R7 and the source of the field effect transistor MOS2, and a transient voltage stabilizing diode TVS1 is also connected in series between the second end of the resistor R5 and the source of the field effect transistor MOS1. The transient voltage stabilizing diode plays a role of transient protection in the circuit. Through its ability to withstand transient voltage in both forward and reverse directions, it can effectively protect other components in the circuit from being damaged by excessive transient voltage, thus protecting the circuit from normal operation.
[0050] The anti-reverse connection circuit further includes a diode D1, the second end of the resistor R1 is connected to the input end of the diode D1, and the output end of the diode D1 is connected to the port T30. The diode D1 is used to reduce leakage current in the circuit when the resistor R1 and the resistor R2 are turned on.
[0051] The battery in the anti-reverse connection circuit is a 12V battery.
[0052] The present invention also provides a battery charging reverse connection prevention method, which can be applied to any of the above-mentioned reverse connection prevention circuits. Using the battery charging reverse connection prevention method of the present invention, the positive and negative poles of the external power supply can be identified by simple electronic devices. If the positive and negative poles of the external power supply are found to be connected incorrectly, the circuit can be quickly shut down. If the connection is correct, the battery can be charged normally. Moreover, the judgment result of this method is accurate and will not cause damage to the electronic devices.
[0053] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A reverse connection protection circuit, characterized in that: The device comprises a charging unit, a detection unit, a control unit, a first switch unit and a second switch unit, The charging unit includes a battery, a port T30, and a port T31, wherein the port T30 corresponds to the positive electrode of the battery, and the port T31 corresponds to the negative electrode of the battery. When the negative pole of the external power source is connected to the port T30 and the positive pole of the external power source is connected to the port T31, the detection unit and the control unit are both turned on, the first switch unit and the second switch unit are turned off, and the charging unit is turned off.
2. The anti-reverse connection circuit according to claim 1, characterized in that: The detection unit includes a transistor T1, a resistor R1, and a resistor R2. The transistor T1 is a PNP transistor. The base of the transistor T1 is connected to the first end of the resistor R1, and the base of the transistor T1 is also connected to the first end of the resistor R2. The second end of the resistor R2 is connected to the emitter of the transistor T1. The emitter of the transistor T1 is connected to port T31, and the collector of the transistor T1 is connected to the first end of the resistor R3.
3. The anti-reverse connection circuit according to claim 1, characterized in that: The control unit includes a transistor T2, a resistor R3 and a resistor R4. The transistor T2 is an NPN transistor. The second end of the resistor R3 is connected to the base of the transistor T2 , the second end of the resistor R3 is also connected to the first end of the resistor R4 , and the second end of the resistor R4 is connected to the emitter of the transistor T2 .
4. The anti-reverse connection circuit according to claim 1, characterized in that: The second switch unit includes a field effect transistor MOS2, The field effect transistor MOS2 is an N-type MOS tube. The source of the field effect transistor MOS2 is connected to the emitter of the transistor T2, the drain of the field effect transistor MOS2 is connected to the drain of the field effect transistor MOS1, the gate of the field effect transistor MOS2 is connected to the first end of the resistor R7, and the second end of the resistor R7 is connected to the emitter of the transistor T2; The second end of the resistor R7 is connected in series with the resistor R8 , and the resistor R8 is connected to the driving signal 2 .
5. The anti-reverse connection circuit according to claim 1, characterized in that: The first switch unit includes the field effect transistor MOS1, The field effect transistor MOS1 is an N-type MOS tube. The source of the field effect transistor MOS1 is connected to the port T31, the gate of the field effect transistor MOS1 is connected to the first end of the resistor R5, and the second end of the resistor R5 is connected to the port T31; The second end of the resistor R5 is connected in series with the resistor R6, and the resistor R6 is connected to the driving signal 1.
6. The anti-reverse connection circuit according to claim 1, characterized in that: Also includes diode D1, The second end of the resistor R1 is connected to the input end of the diode D1 , and the output end of the diode D1 is connected to the port T30 .
7. The anti-reverse connection circuit according to claim 1, characterized in that: A transient voltage regulator diode TVS2 is connected in series between the second end of the resistor R7 and the source of the field effect transistor MOS2, and a transient voltage regulator diode TVS1 is connected in series between the second end of the resistor R5 and the source of the field effect transistor MOS1.
8. The anti-reverse connection circuit according to claim 1, characterized in that: When the positive electrode of the external power source is connected to the port T30 and the negative electrode of the external power source is connected to the port T31, the charging unit works normally.
9. A method for preventing reverse connection of battery charging, characterized in that: Applicable to the anti-reverse connection circuit as described in any one of claims 1-8.