Protection circuit for preventing reverse connection of battery by using detection optocoupler

Abstract

The utility model discloses a protection circuit for preventing reverse connection of a battery by using a detection optocoupler, which comprises an input module, a judgment module, an optocoupler module and a signal output module, and is characterized in that the judgment module is used for judging the current direction of the input module and controlling a switch of the optocoupler module; the optocoupler module is used for determining signal output of the signal output module, and the input module, the judgment module, the optocoupler module and the signal output module are electrically connected in sequence; the signal output module is electrically connected with a control module, and the signal output module outputs a signal to the control module; when the judgment module controls the opening of the optocoupler module, the signal output module outputs a low-level signal to the control module, so that an optocoupler is used as a signal transmission medium, the control logic output by the MCU microprocessor to the charger is triggered based on the change of different levels, a safety protection mechanism during the reverse connection of the battery is effectively realized, and the safety of the battery is improved. Compared with a traditional MOS tube control scheme, the device has the advantages of lower cost, lower power consumption and smaller size.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery charging protection, and specifically relates to a protection circuit for preventing battery reverse connection by using a detection optocoupler. Background Art

[0002] With the continuous development of new energy, people's application of electric energy is becoming more and more extensive, and the requirements for battery charge and discharge management are also becoming more and more stringent. Correspondingly, the charging safety of batteries is becoming increasingly important. In order to improve the safety of batteries during charging, a corresponding protection circuit for preventing battery reverse connection is required.

[0003] Taking a car as an example, when the power source of the car is exhausted and cannot start, if there is an emergency starting power source, the car battery can be powered by using the emergency power source to start the car. Usually, the clips of the emergency starting power source need to be connected to the positive and negative electrodes of the car battery respectively, and then the emergency power source is turned on to supply power; if there is no emergency starting power source, jumper cables can be used to start the car with the help of the battery of another vehicle. Usually, the red jumper cable clip at one end is clamped on the positive electrode (+) of the battery of the vehicle without power, the red jumper cable clip at the other end is clamped on the positive electrode (+) of the battery of the vehicle with power, the black jumper cable clip at one end is clamped on the negative electrode (-) of the battery of the vehicle with power, and the black jumper cable clip at the other end is clamped on the body metal part of the vehicle without power to avoid sparks. When using these two methods, it is easy for the operator to reverse the connection of the emergency power source and the battery because the car is old and it is difficult to see the marks clearly or due to carelessness in connecting the wrong marks, resulting in danger.

[0004] Traditional reverse connection circuits use MOS transistors or diodes to prevent battery reverse connection. When using a diode to prevent battery reverse connection, the diode is easily broken down because the reverse connection current is large. When using a MOS transistor, a MOS transistor with a larger power needs to be selected when the power of the circuit is large, which will cause the circuit to generate more heat and have a larger volume. The circuit of the utility model proposes another scheme with lower power consumption compared with the traditional use of MOS transistors. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a protection circuit for preventing battery reverse connection by using a detection optocoupler to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the utility model provides the following technical solutions:

[0007] A protection circuit for preventing battery reverse connection by using a detection optocoupler includes an input module, a judgment module, an optocoupler module and a signal output module.

[0008] The judgment module is used to judge the current direction of the input module and control the switch of the optocoupler module; the optocoupler module is used to determine the signal output of the signal output module, and the input module, judgment module, optocoupler module and signal output module are electrically connected in sequence; the signal output module is electrically connected to a control module;

[0009] When the judgment module controls the optocoupler module to turn on, the signal output module outputs a low-level signal to the control module.

[0010] In a further technical solution, the input module includes a connection terminal and a resistor R99. The first end of the connection terminal is electrically connected to the input end of the judgment module, the second end of the connection terminal is electrically connected to the output end of the judgment module, the output end of the judgment module is grounded, one end of the resistor R99 is electrically connected to the first end of the connection terminal, the other end of the resistor R99 is electrically connected to the input end of the judgment module, and a resistor R140 is connected in parallel with the resistor R99.

[0011] In a further technical solution, the judgment module includes a triode. The first end of the connection terminal is electrically connected to the b-pole of the triode, the second end of the connection terminal is electrically connected to the e-pole of the triode, the c-pole of the triode is electrically connected to the optocoupler module; the e-end of the triode is grounded.

[0012] In a further technical solution, the optocoupler module includes an optocoupler. The c-pole of the triode is electrically connected to the second end of the optocoupler, the first end of the optocoupler is electrically connected to a first external power supply, the third end of the optocoupler is grounded, and one end of the fourth end of the optocoupler is electrically connected to the signal output module.

[0013] In a further technical solution, the signal output module includes a second external power supply and a resistor R79. The second external power supply is electrically connected to the resistor R79, the resistor R79 is electrically connected to the fourth end of the optocoupler, and the resistor R79 is electrically connected to the output end of the signal output module.

[0014] In a further technical solution, the control module is electrically connected to a reminder module.

[0015] In a further technical solution, the e-pole of the triode is electrically connected to a third resistor R110, the third resistor R110 is electrically connected to a first diode D36, and the anode of the first diode D36 is electrically connected to the third resistor R110.

[0016] In a further technical solution, the triode and the third resistor R110 are connected in parallel and electrically connected to a zener diode D32, and the cathode of the zener diode D32 is electrically connected to one end of the resistor R99 and the resistor R140.

[0017] Advantages of the present utility model:

[0018] The present utility model uses an optocoupler as a signal transmission medium, and based on the changes in different levels, triggers the control logic of the MCU microprocessor for the output of the charger, effectively realizing a safety protection mechanism when the battery is reversely connected. This device has lower costs, power consumption, and a smaller volume compared to the traditional MOS transistor control scheme.

[0019] Other features and advantages of the present utility model will be described in detail in the following specific implementation section. Brief Description of the Drawings

[0020] Figure 1 : Circuit diagram of the detection unit of the present utility model.

[0021] Reference numerals in the drawings: 1. Input module; 2. Judgment module; 3. Optocoupler module; 4. Signal output module; Specific Implementation Manner

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model.

[0023] Please refer to Figure 1 ;

[0024] The present utility model discloses a protection circuit for preventing battery reverse connection by detecting an optocoupler. This circuit has lower costs, power consumption, and a smaller volume compared to the traditional MOS transistor scheme for preventing battery reverse connection. This circuit can be applied to any circuit that needs to prevent reverse connection. In this embodiment, taking an automobile as an example, when the power source of the automobile is exhausted and cannot start, if there is an emergency starting power source, the emergency power source can be used to supply power to the automobile battery to start the automobile. Usually, the clips of the emergency starting power source need to be connected to the positive and negative electrodes of the automobile battery respectively, and then the emergency power source is turned on to supply power; it is easy for the operator to connect the wrong mark due to the old age of the automobile and difficulty in seeing the mark clearly or carelessness, resulting in the reverse connection of the emergency power source and the battery, and then causing danger.

[0025] In an embodiment, a protection circuit for preventing battery reverse connection using a detection optocoupler is disclosed, including an input module 1, a judgment module 2 electrically connected to the input module 1, and an optocoupler module 3 electrically connected to the judgment module 2. The judgment module 2 is used to judge the current direction of the input module 1 and to control the switch of the optocoupler module 3; it also includes a signal output module 4 for outputting signals, and the signal output module 4 is also electrically connected to a control module; the optocoupler module 3 is used to determine the signal output of the signal output module 4. The control module includes an MCU microprocessor, which judges whether the polarity of the input power supply is correct through the protection circuit, and thus sends a high or low level signal to the MCU microprocessor to control the main switch of the device. More specifically, the signal output module 4 can output a high level signal or a low level signal according to the switch of the optocoupler module 3. When the optocoupler module 3 is turned on, the signal output module 4 conducts a low level signal, and the MCU microprocessor can turn on the switch controlling the external power supply when receiving the low level signal. When the optocoupler module 3 is turned off, the signal output module 4 conducts a high level signal, and the MCU microprocessor can turn off the switch controlling the external power supply when receiving the high level signal. It should be noted that the MCU microprocessor is also electrically connected to a reminder module. When the signal output module 4 conducts a high level signal, the MCU microprocessor can remind the operator that the emergency power supply and the battery are connected wrongly while turning off the switch controlling the external power supply when receiving the high level signal.

[0026] The working principle of the present utility model is as follows: when the input module 1 is correctly connected to the external power supply, the judgment module 2 can enable the optocoupler module 3 according to the current direction of the input module 1, and then determine that the signal output module 4 can input a high level signal into the MCU microprocessor. When the MCU microprocessor receives the high level signal, it can turn on the switch controlling the external power supply, so that the external power supply starts normal power supply, and the external power supply can charge the vehicle-mounted battery during normal power supply; on the contrary, when the input module 1 is reversely connected to the external power supply, the judgment module 2 can turn off the optocoupler module 3 according to the current direction of the input module 1, and then make the signal output module 4 generate a low level signal and input it into the MCU microprocessor. When the MCU microprocessor receives the low level signal, it can turn off the switch controlling the external power supply, so that the external power supply cannot supply power to the vehicle-mounted battery, thus playing a role in preventing reverse connection protection. At the same time, the MCU microprocessor can control the reminder module to emit sound or light to remind the operator that the emergency power supply and the battery are connected wrongly.

[0027] Specifically, the input module 1 includes a connection terminal and a resistor R99, the judgment module 2 includes a triode, the optocoupler module 3 includes an optocoupler, and the signal output module 4 includes a second external power supply and a resistor R79. The second terminal of the connection terminal and the e terminal of the triode form a first node, and the first node is grounded. The first terminal of the connection terminal is electrically connected to the b pole of the triode, and a resistor R99 is connected in series between the first terminal of the connection terminal and the b pole of the triode. The resistance value of the resistor R99 is 6.2K, and a resistor R140 with the same resistance value is connected in parallel with the resistor R99. A third resistor R110 is connected in series between the e terminal of the triode and the first node. The third resistor R110 is electrically connected to a first diode D36. The first diode D36 is located between the first node and the ground point, and the anode of the first diode D36 is electrically connected to the first node; the resistor R99, the resistor R140 and the triode form a second node. The triode and the third resistor are connected in parallel with a zener diode D32. The anode of the zener diode D32 is electrically connected to the first node. By connecting the zener diode D32 in parallel with the triode and the third resistor R110, the zener diode D32 can protect the triode from being damaged; the c terminal of the triode is electrically connected to the second terminal of the optocoupler. The first terminal of the optocoupler is electrically connected to a first external power supply. In this embodiment, the voltage of the first external power supply is preferably +5V, and a resistor R78 is connected in series at the first terminal of the optocoupler. The third terminal of the optocoupler is grounded. One end of the fourth terminal of the optocoupler is electrically connected to a second external power supply, and the voltage of the second external power supply is +3.3V. A resistor R81 is connected in series between the other end of the fourth terminal of the optocoupler and the output terminal of the signal output module 4. A third node is formed between the resistor 81 and the output terminal of the output module 4. A capacitor C50 is electrically connected between the third node and the third terminal of the optocoupler. The third node is externally connected to a diode D22 and a third external power supply of 3.3V in sequence, and the anode of the diode D22 is electrically connected to the capacitor C50.

[0028] The specific working principle is as follows: When the second terminal of the connection terminal is electrically connected to the positive pole of the external power supply and the first terminal of the connection terminal is electrically connected to the negative pole of the external power supply, the first terminal of the connection terminal is connected to a negative voltage, so the b pole of the triode is at a low level. At this time, the triode is in a cut-off state. The voltage of the first external power supply is 5V, and the first external power supply is electrically connected to the first terminal of the optocoupler. Because the b pole of the triode is at a low level and not conducting, that is, the triode is cut off, an effective circuit cannot be formed among the first external power supply, the first terminal of the optocoupler, the second terminal of the optocoupler, the C-E pole of the triode, and the first node. As a result, no current passes between the first terminal and the second terminal of the optocoupler, that is, the optocoupler is not conducting, and the third terminal and the fourth terminal of the optocoupler are open-circuited; the fourth terminal of the optocoupler connected to the second external power supply is at a high level of 3.3V. Therefore, a high-level signal of 3.3V is output from the fourth terminal of the optocoupler, that is, the output terminal of the output module 4 outputs a high-level signal to the electrically connected MCU microprocessor. When the MCU microprocessor receives the high-level signal, it can turn on the switch controlling the external power supply, enabling the external power supply to start normal power supply, and the normal power supply of the external power supply can charge the vehicle-mounted battery;

[0029] On the contrary, when the second terminal of the connection terminal is connected to the negative pole of the external power supply and the first terminal of the connection terminal is connected to the positive pole of the external power supply, that is, when the protection circuit is reversely connected to the external power supply, the first terminal of the connection terminal is connected to a positive voltage, so the b pole of the triode is at a high level. At this time, the triode is in a conducting state. The voltage of the first external power supply is 5V, and the first external power supply is electrically connected to the first terminal of the optocoupler. The first external power supply, the optocoupler, and the C-E pole of the triode are grounded to form a path, enabling the optocoupler to conduct and emit light, and making the third terminal and the fourth terminal of the optocoupler conduct. At this time, a path is formed among the 3.3V of the second external power supply, the third terminal of the optocoupler, the fourth terminal of the optocoupler, and the ground terminal, causing a low level to be generated at the output terminal of the output module 4 and input into the MCU microprocessor. When the MCU microprocessor receives the low-level signal, it can turn off the switch controlling the external power supply, preventing the external power supply from supplying power to the vehicle-mounted battery, thereby playing a role in reverse connection protection. At the same time, the MCU microprocessor can control the reminder module to emit a sound or light to remind the operator that the emergency power supply and the battery are connected wrongly.

[0030] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present utility model. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0031] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims

1. A battery reverse connection protection circuit using a detection optocoupler, comprising an input module (1), a judgment module (2), an optocoupler module (3) and a signal output module (4), characterized in that : The input module (1), the judgment module (2), the optocoupler module (3) and the signal output module (4) are electrically connected in sequence; the judgment module (2) is used to judge the current direction of the input module and to control the switch of the optocoupler module (3); the optocoupler module (3) is used to determine the signal output of the signal output module (4), and the signal output module (4) is electrically connected to a control module; When the judgment module (2) controls the optocoupler module (3) to turn on, the signal output module (4) outputs a low-level signal to the control module.

2. The anti-battery reverse connection protection circuit using a detection optocoupler according to claim 1, characterized in that, The input module (1) includes a connection terminal and a resistor R99. The first end of the connection terminal is electrically connected to the input end of the judgment module (2), the second end of the connection terminal is electrically connected to the output end of the judgment module (2), the output end of the judgment module (2) is grounded, one end of the resistor R99 is electrically connected to the first end of the connection terminal, the other end of the resistor R99 is electrically connected to the input end of the judgment module (2), and a resistor R140 is connected in parallel with the resistor R99.

3. The anti-battery reverse connection protection circuit using a detection optocoupler according to claim 2, characterized in that, The judgment module (2) includes a triode. The first end of the connection terminal is electrically connected to the b-pole of the triode, the second end of the connection terminal is electrically connected to the e-pole of the triode, the c-pole of the triode is electrically connected to the optocoupler module (3); the e-end of the triode is grounded.

4. A battery reverse connection protection circuit using a detection optocoupler according to claim 3, characterized in that The optocoupler module (3) includes an optocoupler. The c-pole of the triode is electrically connected to the second end of the optocoupler, the first end of the optocoupler is electrically connected to a first external power supply, the third end of the optocoupler is grounded, and one end of the fourth end of the optocoupler is electrically connected to the signal output module (4).

5. The anti-battery reverse connection protection circuit using a detection optocoupler according to claim 4, characterized in that, The signal output module (4) includes a second external power supply and a resistor R79. The second external power supply is electrically connected to the resistor R79, the resistor R79 is electrically connected to the fourth end of the optocoupler, and the resistor R79 is electrically connected to the output end of the signal output module (4).

6. The anti-battery reverse connection protection circuit using a detection optocoupler according to claim 1, wherein The control module is electrically connected to a reminder module.

7. A battery reverse connection protection circuit using a detection optocoupler according to claim 3, characterized in that, The e-pole of the triode is electrically connected to a third resistor R110, the third resistor R110 is electrically connected to a first diode D36, and the anode of the first diode D36 is electrically connected to the third resistor R110.

8. A battery reverse connection protection circuit using a detection optocoupler according to claim 7, characterized in that, The triode and the third resistor R110 are connected in parallel and electrically connected to a zener diode D32. The cathode of the zener diode D32 is electrically connected to one end of the resistor R99 and the resistor R140.

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