Anti-reverse connection and disconnection detection circuit for security battery and detection method thereof

Abstract

The application provides a reverse connection and non-connection detection circuit for a security battery and a detection method thereof, which comprises a power supply circuit and a detection protection circuit; the power supply circuit is connected to the positive and negative poles of the security battery to charge and discharge the security battery; and the detection protection circuit is connected in parallel to the positive and negative poles of the security battery to realize reverse connection and non-connection detection of the battery. The application provides a reverse connection and non-connection detection circuit for a security battery and a detection method thereof, which adds a detection circuit outside the power supply circuit, takes the BAT- level of the security battery as a detection standard, can effectively judge the reverse connection and non-connection of the security battery, and prevents the possibility of line backflow during reverse connection through a unidirectional conduction element.

Description

Technical Field

[0001] This invention relates to a reverse connection and disconnection detection circuit for security batteries and a detection method thereof. Background Technology

[0002] LAD is an economical security battery, mainly used for power supply in special situations. Therefore, it needs to be charged and stored when not in use. However, this will affect the user's main circuit voltage. Since the power of the battery charging line is generally between 15W and 160W, which is a large range, the general main circuit cannot meet the stable voltage when the power is turned on for charging. Therefore, a floating buck circuit needs to be built in the battery line to support it.

[0003] Meanwhile, security batteries need to have reverse connection and disconnection protection, so a detection circuit needs to be added to the power supply line. The detection circuit requires an auxiliary power supply, and the detection and protection also need to be achieved by the MCU controlling the on and off of the MOSFET or relay. As a result, the wiring connection of security batteries becomes very complicated and the connection cost is very high, making it difficult to use widely.

[0004] However, the Floating Bucket circuit architecture is simple and inexpensive. It can effectively change the charging voltage when the security battery is charging, reducing the impact on the main circuit voltage. If a simple and practical detection circuit can be built on this basis, it can both protect the security battery and not affect the main circuit voltage when the security battery is charging. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a reverse connection and unconnection detection circuit and detection method for security batteries. The aim is to build a detection and protection circuit on the step-down circuit through circuit design, so that the security battery can realize reverse connection and unconnection detection and protection.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a reverse connection and disconnection detection circuit for a security battery, comprising a power supply line for charging or discharging the security battery and a detection protection line for detecting reverse connection or disconnection of the security battery, wherein the power supply line and the detection protection line are respectively connected to BAT+ and BAT- of the security battery; BAT- is grounded; and a conduction switch is provided in the power supply line.

[0007] The detection and protection circuit includes a protection circuit and a detection circuit. The detection circuit is equipped with a connection unit, a comparison unit, and a control unit. The detection and protection circuit is grounded.

[0008] One end of the control unit is connected to the connection unit to receive voltage signals, and the other end is connected to the control circuit of the conduction switch. The control unit controls the conduction or disconnection of the conduction switch by controlling the control circuit, and finally controls the conduction or disconnection of the power line.

[0009] Furthermore, the protection circuit includes a pressure-reducing unidirectional conducting element, a first resistor, a first transistor, and a second unidirectional conducting element; wherein the first transistor is provided with a first pin, a second pin, and a third pin; the pressure-reducing unidirectional conducting element is connected to BAT+, and is connected in series with the first resistor, and is also connected to the first pin of the first transistor; the second pin of the first transistor is connected to the second unidirectional conducting element, the other end of the second unidirectional conducting element is connected to BAT-, and the third pin of the first transistor is connected outward to the connection unit; the second unidirectional conducting element is used to prevent reverse battery discharge when the security battery is reverse-connected; the detection circuit is connected in parallel on the side of the second unidirectional conducting element closer to BAT-.

[0010] Furthermore, the connection unit includes a second resistor, a third resistor, a second transistor, a fourth resistor, and a fifth resistor; wherein the second transistor is provided with a first pin, a second pin, and a third pin; one end of the second resistor is connected in series with the third resistor to the second pin of the second transistor, and the other end is connected to the protection circuit; the protection circuit is connected between the second resistor and the third resistor, forming a parallel connection with the second resistor; the third pin of the second transistor is connected to the fourth resistor and extends outward to a normally closed opening; the fifth resistor is connected between the first pin and the third pin of the second transistor, and the fifth resistor shares a common ground with the second transistor; when the protection circuit cannot conduct, the current flows from the protection circuit to the second resistor, the third resistor, and the second transistor before being grounded; when the protection circuit conducts, the current flows directly through the third resistor to the second transistor, and then through the third pin of the second transistor to the normally closed opening, at which time the normally closed opening is opened, allowing external electrical loads to be connected.

[0011] Furthermore, the comparison unit includes a third unidirectional conducting element, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, and an amplifier; the amplifier is provided with a second input terminal, a first input terminal, and an output terminal; the output terminal is connected to the control unit, the second input terminal is connected to the sixth resistor, the sixth resistor is connected in series with the third unidirectional conducting element and then connected to the protection circuit; one end of the seventh resistor is connected to the connection unit, and the other end is connected to the sixth resistor and in parallel to the second input terminal of the amplifier; the eighth resistor is connected to the ninth resistor and in parallel to the first input terminal, and the eighth resistor is connected to an external auxiliary positive voltage; the ninth resistor is connected to the connection unit, the output terminal is connected to the control unit, and the seventh resistor, the ninth resistor, and the connection unit share a common ground.

[0012] Furthermore, a third capacitor and a tenth resistor are connected between the output terminal and the first input terminal, and the third capacitor and the tenth resistor are connected in series.

[0013] Furthermore, a fourth capacitor and an external positive voltage are connected in parallel on the amplifier. The fourth capacitor is connected to both sides of the second input terminal and the first input terminal, and a ground is provided between the fourth capacitor and the first input terminal.

[0014] Furthermore, the control unit includes an eleventh resistor, a twelfth resistor, a third transistor, and a thirteenth resistor; wherein the third transistor is provided with a first pin, a second pin, and a third pin; one end of the eleventh resistor is connected to the connection unit, and the other end is connected to the third pin of the third transistor; one end of the twelfth resistor is grounded with the connection unit, and the other end is connected to the third pin of the third transistor, and is connected in parallel with the eleventh resistor; the second pin of the third transistor is connected to the thirteenth resistor, and the connection unit is connected through the thirteenth resistor; a connection port is provided outward between the thirteenth resistor and the second pin of the third transistor.

[0015] Furthermore, the connection port of the third transistor is connected to an MCU, which is connected to the control circuit of the on / off switch in the power supply line, and the MCU controls the on / off switch to be turned on or off.

[0016] Furthermore, the control unit includes a fourteenth resistor, a fifteenth resistor, a fourth unidirectional conducting element, and a fourth transistor; wherein the fourth transistor is provided with a first pin, a second pin, and a third pin; one end of the fourteenth resistor is connected in parallel with the fifteenth resistor to the comparator unit, and the other end is connected in series with the fourth unidirectional conducting element; the control circuit is connected to the on / off switch, and the on / off switch is closed or opened by the conduction or non-conduction of the control circuit; the other end of the fifteenth resistor is connected to the first pin (Q41) of the fourth transistor; the third pin of the fourth transistor is grounded, and the second pin is connected to a normally closed opening.

[0017] Furthermore, the power supply line includes a charging line for charging the security battery and a discharging line for discharging the security battery, wherein,

[0018] The charging circuit is equipped with a first charging capacitor, a second charging capacitor, a switching switch, and a one-way charging element; the first charging capacitor, the second charging capacitor, and the one-way charging element are connected in parallel to each other and are all connected to BAT+ and BAT-, and are connected in series with the switching switch; the switching switch is equipped with a winding coil, and the two ends of the winding coil extend outward to connect to the control circuit, which is connected to the control unit;

[0019] The discharge circuit includes a discharge capacitor, a first discharge transistor, a second discharge transistor, and a sixteenth resistor. The first discharge transistor has a first pin, a second pin, and a third pin, and the second discharge transistor also has a first pin, a second pin, and a third pin. One end of the discharge capacitor is connected to BAT+, and the second pin of the first discharge transistor is connected in parallel to the charging unidirectional conduction element. The second pin of the second discharge transistor is connected to the on / off switch, and the sixteenth resistor is connected to the third pin of the second discharge transistor. The discharge capacitor, the sixteenth resistor, and the first pin of the second discharge transistor share a common ground.

[0020] Furthermore, the switch is a relay, which is controlled according to the electrical signal from the control unit.

[0021] Furthermore, the resistance values ​​of the sixth, seventh, eighth, and ninth resistors are set in a proportional manner, and the ratio setting satisfies the requirement that the security battery is working normally. Specifically, the ratio of the eighth resistor to the ninth resistor is set by setting the voltage of the first input terminal; and the ratio of the sixth resistor to the seventh resistor determines the voltage of the second input terminal.

[0022] Furthermore, the detection method is as follows:

[0023] When the power line is turned on, the amplifier causes different output levels at the output terminal due to the voltage difference between the second input terminal and the first input terminal, resulting in two different situations. At this time, the on / off switch is controlled differently according to the different output levels.

[0024] When the output level is low, the current flows to the control unit, then to the MCU, and then to the control line or directly to the control line. At this time, the MCU detects a high level and controls the control line. The control line controls the on switch to turn on the on switch, and the power line remains on.

[0025] When the output level is high, the current flows to the control unit, turning on the third or fourth transistor, and no longer flows to the MCU or control circuit. The connected MCU detects a low level, and the control circuit is not conducting, causing the on / off switch to not conduct, thereby disconnecting the power supply line for protection.

[0026] Compared with existing technologies, the present invention provides a detection circuit and method for preventing reverse connection and disconnection of security batteries. By adding a detection circuit outside the power supply line and using the output level as the detection standard, it can not only effectively determine the reverse connection and disconnection status of the security battery, but also reduce the voltage when the battery is charging normally, reducing the impact on the voltage of the user's main circuit. Furthermore, it prevents the possibility of reverse current in the circuit through a unidirectional conducting element. At the same time, the first transistor does not conduct when the security power supply is disconnected or reversed, that is, it does not consume battery power and can achieve zero leakage current. Attached Figure Description

[0027] Figure 1 The diagram shows the architecture of the detection and protection circuit of the present invention.

[0028] Figure 2 A schematic diagram of the power supply circuit of the present invention is shown.

[0029] Figure 3 This diagram illustrates a second embodiment of the detection and protection circuit of the present invention.

[0030] in: Figure 2 The arrows in the diagram indicate the direction of the charging current in the charging line 11 and the direction of the discharging current in the discharging line 12.

[0031] 1. Power supply line; 2. Detection and protection line; 11. Charging line; 12. Discharging line; 21. Protection line; 22. Detection line; 221. Connection unit; 222. Comparison unit; 223. Control unit; 8. Output terminal; 9. First input terminal; 10. Second input terminal;

[0032] BAT+. Positive terminal of the security battery, BAT-. Negative terminal of the security battery, R2. Second resistor, R3. Third resistor, Q2. Second transistor (including Q21. First pin, Q22. Second pin, Q23. Third pin), R4. Fourth resistor, R5. Fifth resistor, D3. Third unidirectional conducting element, R6. Sixth resistor, R7. Seventh resistor, R8. Eighth resistor, R9. Ninth resistor, U1. Amplifier, C3. Third capacitor, R10. Tenth resistor, R11. Eleventh resistor, R12. Twelfth resistor, Q3. Third transistor (including Q31. First pin, Q32. Second pin, Q33. Third pin), R13. Thirteenth resistor, R14. Fourteenth resistor, R15. Fifteenth resistor, D4. Fourth unidirectional conducting element, Q4 The fourth transistor (including Q41. pin 1, Q42. pin 2, Q43. pin 3), C4. fourth capacitor, VCC. external positive voltage, D1. reduced voltage unidirectional conduction element, R1. first resistor, Q1. first transistor (including Q11. pin 1, Q12. pin 2, Q13. pin 3), D2. second unidirectional conduction element, C1. first charging capacitor, C2. second charging capacitor, KY1. conduction switch, D5. charging unidirectional conduction element, C5. discharging capacitor, Q5. first discharging transistor (including Q51. pin 1, Q52. pin 2, Q53. pin 3), Q6. second discharging transistor (including Q61. pin 1, Q62. pin 2, Q63. pin 3), BAT-NC. normally closed open port. Detailed Implementation

[0033] Example 1

[0034] like Figure 1 , Figure 2 The diagram shows a reverse connection and disconnection detection circuit for a security battery. Power line 1 connects the positive terminal BAT+ and the negative terminal BAT- of the security battery. The positive and negative terminals of the security battery are connected to the user load. When the load starts, the security battery discharges; when the load stops, the security battery charges. Therefore, power line 1 includes a charging line 11 and a discharging line 12 to realize the charging and discharging functions. BAT- is grounded. A conduction switch KY1 is provided in power line 1 to control the conduction and shutdown of power line 1.

[0035] In this embodiment, the on switch KY1 is a relay.

[0036] The detection and protection circuit 2 is connected to the positive and negative terminals of the security battery and is connected in parallel with the power supply circuit 1. An MCU and a control circuit connected to the on switch KY1 are connected in series between the detection and protection circuit 2 and the power supply circuit 1.

[0037] The detection and protection line 2 includes a protection line 21 and a detection line 22. The detection line 22 is equipped with a connection unit 221, a comparison unit 222, and a control unit 223. The detection and protection line 2 is grounded. The MCU controls the opening or closing of the on / off switch KY1 by detecting the high or low level of the output level of the detection line 22.

[0038] One end of the control unit 223 is connected to the comparator unit 222 to receive voltage signals, and the other end is connected to the on switch KY1 via the MCU. The control unit 223 controls the power line 1 to be turned on or off by controlling the on switch KY1 to be turned on or off.

[0039] The protection circuit 21 includes a pressure-reducing unidirectional conducting element D1, a first resistor R1, a first transistor Q1, and a second unidirectional conducting element D2. The first transistor Q1 has a first pin Q11, a second pin Q12, and a third pin Q13. The pressure-reducing unidirectional conducting element D1 is connected to BAT+, and is also connected in series with the first resistor R1 and to the first pin Q11 of the first transistor Q1. The second pin Q12 of the first transistor Q1 is connected to the second unidirectional conducting element D2, and the other end of the second unidirectional conducting element D2 is connected to BAT-. The third pin of the first transistor Q1 is connected outward to the connection unit 221. The second unidirectional conducting element D2 is used to prevent reverse battery discharge when the security battery is reverse-connected. The detection circuit 22 is connected in parallel to the end of the second unidirectional conducting element D2 near BAT-.

[0040] Connection unit 221 includes a second resistor R2, a third resistor R3, a second transistor Q2, a fourth resistor R4, and a fifth resistor R5. The second transistor Q2 has a first pin Q21, a second pin Q22, and a third pin Q23. One end of the second resistor R2 is connected in series with the third resistor R3 to the second pin Q22 of the second transistor Q2, and the other end is connected to the protection circuit 21. The protection circuit 21 connects the second resistor R2 and the third resistor R3, forming a parallel connection with the second resistor R2. The third pin Q23 of the second transistor Q2 is connected to the fourth resistor R4 and extends outwards to the normally closed opening. The fifth resistor R5 is connected between the first pin Q21 and the third pin Q23 of the second transistor Q2. The fifth resistor R5 and the second transistor Q2 share a common ground. When the voltage is low, the protection circuit 21 cannot flow. The current flows from the protection circuit 21 to the second resistor R2, the third resistor R3 and the second transistor Q2 and then to the ground. When the voltage is high, the protection circuit 21 is connected. The current flows directly through the third resistor R3 to the second transistor Q2, and then through the third pin Q23 of the second transistor Q2 to the normally closed open port BAT-NC. The normally closed open port BAT-NC is then open, and the external electrical load is connected.

[0041] The comparator unit 222 includes a third unidirectional conducting element D3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and an amplifier U1. The amplifier U1 has a second input terminal 10, a first input terminal 9, and an output terminal 8. The second input terminal 10 is connected to the sixth resistor R6, which is connected in series with the third unidirectional conducting element D3 and connected to the protection circuit 21. One end of the seventh resistor R7 is connected to the connection unit 221, and the other end is connected to the sixth resistor R6 and in parallel to the second input terminal 10 of the amplifier U1. The eighth resistor R8 and the ninth resistor R9 are connected in parallel to the first input terminal 9, and the eighth resistor R8 is connected to an external auxiliary positive voltage. The ninth resistor R9 is connected to the connection unit 221, and the output terminal 8 is connected to the control unit 223. The seventh resistor R7, the ninth resistor R9, and the connection unit 221 share a common ground.

[0042] The control unit 223 includes an eleventh resistor R11, a twelfth resistor R12, a third transistor Q3, and a thirteenth resistor R13. The third transistor has a first pin Q31, a second pin Q32, and a third pin Q33. One end of the eleventh resistor R11 is connected to the comparator unit 222, and the other end is connected to the third pin Q33 of the third transistor Q3. One end of the twelfth resistor R12 is grounded with the connection unit 221, and the other end is connected to the third pin Q33 of the third transistor Q3, and is connected in parallel with the eleventh resistor R11. The second pin Q32 of the third transistor Q3 is connected to the thirteenth resistor R13, and is connected to the connection unit 222 through the thirteenth resistor R13. A connection port for connecting to the MCU is provided between the thirteenth resistor R13 and the second pin Q32 of the third transistor Q3. The MCU connects to the control circuit, and then connects to the on / off switch KY1 in the power supply line 1. The MCU directly controls the control circuit, and thus controls the on / off switch KY1.

[0043] Power line 1 includes a charging line 11 for charging the security battery and a discharging line 12 for discharging the security battery, wherein,

[0044] The charging line 11 is equipped with a first charging capacitor C1, a second charging capacitor C2, and a one-way charging conduction element D5; the first charging capacitor C1, the second charging capacitor C2, and the one-way charging conduction element D5 are connected in parallel to each other and are all connected to BAT+ and BAT-, and are connected in series with the on switch KY1. The on switch KY1 is equipped with a winding coil, and the two ends of the winding coil extend outward to connect to the control line, which is connected to the control unit 223.

[0045] The discharge circuit 12 is equipped with a discharge capacitor C5, a first discharge transistor Q5, and a second discharge transistor Q6. The first discharge transistor Q5 has a first pin Q51, a second pin Q52, and a third pin Q53, and the second discharge transistor Q6 has a first pin Q61, a second pin Q62, and a third pin Q63. One end of the discharge capacitor C5 is connected to the positive terminal of the charging circuit 11, and the other end is connected to the first pin Q51 of the first discharge transistor Q5 and the first pin Q61 of the second discharge transistor Q6. The first discharge transistor Q5 and the second discharge transistor Q6 are connected in parallel to the negative terminal of the charging circuit 11. The second pin Q52 of the first discharge transistor Q5 is connected to one end of the charging unidirectional conduction element D5 of the charging circuit 11 and is connected in parallel with the charging unidirectional conduction element D5. The second pin Q62 of the second discharge transistor Q6 is connected to one end of the on switch KY1 and is also connected to BAT-.

[0046] In this embodiment, the circuit principle of the detection circuit is as follows:

[0047] When power supply line 1 is turned on, the voltages at the second input terminal 10 and the first input terminal 9 are different, resulting in different output levels at the output terminal 8 of amplifier U1. This leads to two different situations, and therefore the switching switch KY1 can be either on or off.

[0048] When output terminal 8 is low, the third transistor Q3 is not turned on. At this time, the current flows from the external auxiliary positive voltage through the thirteenth resistor R13 to the MCU. The MCU detects the high level. The MCU connects to the control circuit and then controls the on switch KY1 to turn on. At this time, the security battery is connected normally and there is no abnormality.

[0049] When output terminal 8 is high, the third transistor Q3 is turned on. At this time, the MCU detects a low level and controls the on switch KY1 to turn off through the control circuit. At this time, the security battery connection circuit is abnormal, and there is a situation of reverse connection or no connection. At the same time, the protection circuit 21 is equipped with a second unidirectional conduction element D2, which can prevent the security battery from backflowing when the security battery is reverse connected. At the same time, if the voltage to ground of BAT- rises, the security battery is reverse connected; otherwise, it is not connected.

[0050] When the switch KY1 is closed, the first transistor Q1 in the protection circuit 21 is not turned on, which causes the entire detection and protection circuit 2 to be non-conductive. Therefore, when the power supply circuit 1 is not turned on, the security battery will not be consumed, and leakage current can be eliminated.

[0051] Therefore, in this embodiment, the detection method is as follows: the output level of the MCU detection amplifier U1 is used. When the output level is high, it indicates that the security battery is in normal use. When the output level is low, it indicates that the security battery is abnormal. The on / off switch KY1 is then turned off to disconnect the power line 1.

[0052] When the specific parameters of each component are as follows, and all transistors are MOSFETs, the amplifier is an operational amplifier of model U301C, and the safety battery voltage is 36V:

[0053] The main circuit output voltage is V+, which is 41.5V. The external auxiliary positive voltage is 3.3V. The resistance of the sixth resistor R6 is 200KΩ, the resistance of the seventh resistor R7 is 10KΩ, the resistance of the eighth resistor R8 is 22KΩ, the resistance of the ninth resistor R9 is 10KΩ, and the resistance of the first resistor R1 is 30KΩ. The specific operating parameters are as follows:

[0054] The voltage V9 at the first input terminal of operational amplifier U1 is set as follows:

[0055]

[0056] 1. The security battery is working normally:

[0057] V + Connect to the positive terminal BAT+ of the security battery.

[0058] V + =V BAT+ =41.5v

[0059] Also, the battery voltage V BAT =36V>31.5V

[0060] At this time V BAT -≤V + -V BAT =41.5-31.5=10V

[0061] Therefore, the voltage to ground of BAT- is no higher than 10V;

[0062] At this time, the voltage V at the second input terminal 10 10 for:

[0063]

[0064] V9>V 10 At this time, the output terminal 8 of the operational amplifier U1 is at a low level, the third transistor Q3 is not conducting, the current flows from the outside to the MCU, the MCU detects the high level, the current flows to the control circuit, conducts the winding coil, and then turns on the switch KY1, the power line 1 remains on, and the safety battery is connected in the correct direction.

[0065] 2. When the battery is not connected:

[0066] V + When outputting externally, the unidirectional conducting element D1 is reduced to zero, and BAT- is charged through the first resistor R1 and the first transistor Q1.

[0067]

[0068] At this time, the voltage V output from the second input terminal 10 10 for:

[0069]

[0070] V9 < V 10 At this time, the output terminal 8 of the operational amplifier U301C outputs a high level, and the third transistor Q3 is turned on; the MCU is connected to the second pin Q32 of the third transistor Q3, and receives a low level. The current no longer flows to the control circuit conduction switch KY1, which is turned off, the power line 1 is no longer turned on, the entire circuit is disconnected, and the security power supply no longer works.

[0071] 3. When the battery is reversed:

[0072] At this time, the voltage between BAT- and GND is the output V+ plus the battery voltage V. BAT ;

[0073] V BAT- =V + +V BAT =41.5 + 31.5 = 73V;

[0074] At this time, the voltage V output from the second input terminal 10 10 for:

[0075]

[0076] When V9 < V10, the output of terminal 8 of operational amplifier U301C is high, and the third transistor Q3 is turned on. The MCU is connected to the second pin Q32 of the third transistor Q3 and receives a low level. The current no longer flows to the control circuit, the winding coil of switch KY1 is no longer conducting, switch KY1 is turned off, power line 1 is no longer conducting, the entire circuit is disconnected, and the security power supply no longer works.

[0077] Example 2

[0078] like Figure 2 , Figure 3The circuit shown is a reverse connection and disconnection detection circuit for a security battery, including a power line 1 and a detection and protection circuit 2. The detection and protection circuit 2 is provided with a protection line 21 and a detection line 22. The detection line 22 includes a connection unit 221, a comparison unit 222, and a control unit 223. The connection structure of the power line 1, the protection line 21, the connection unit 221, and the comparison unit 222 is consistent with that in Embodiment 1. The control unit 223 includes a fourteenth resistor R14, a fifteenth resistor R15, a fourth unidirectional conducting element D4, and a fourth transistor Q4. The fourth transistor Q4 is provided with... It has a first pin Q41, a second pin Q42, and a third pin Q43; one end of the fourteenth resistor R14 is connected in parallel with the fifteenth resistor R15 to the comparator unit 222, and the other end is connected in series with the fourth unidirectional conducting element D4, and is connected to the on switch KY1 through the control line. When the control line is on, the on switch KY1 is turned on, and when the control line is closed, the on switch KY1 is turned off; the other end of the fifteenth resistor R15 is connected to the first pin Q41 of the fourth transistor Q4; the third pin Q43 of the fourth transistor Q4 is grounded, and the second pin Q42 is connected to the normally closed open BAT-NC.

[0079] The circuit principle is as follows:

[0080] When the output terminal 8 is at a low level, the first pin Q41 of the fourth transistor Q4 receives a low level and cannot be turned on. The current flows through the fourteenth resistor R14 and the fourth unidirectional conducting element to the control circuit connected to the conduction switch KY1. The control circuit turns on the winding coil, turns on the conduction switch KY1, keeps the power line 1 on, and keeps the safety battery working normally.

[0081] When the output terminal 8 is at a high level, the first pin Q41 of the fourth transistor Q4 receives a high level and is turned on. The current flows through the fourth transistor Q4 to the normally closed open BAT-NC. Therefore, the control circuit connected to the winding coil in the on switch KY1 is disconnected, and then the on switch KY1 is disconnected, the power line 1 is disconnected, and the security battery is turned off.

[0082] In this embodiment, except for the fourth transistor, all other transistors are MOSFETs, and the fourth transistor is a bipolar transistor. The detection method is as follows:

[0083] When power line 1 is turned on, the voltage difference between the second input terminal 10 and the first input terminal 9 of amplifier U1 causes the output level of the output terminal 8 to be different, resulting in two different situations. At this time, the different output levels control the conduction switch KY1 of power line 1 differently.

[0084] When the output level is low, it indicates that the circuit of the security battery is normal and there is no abnormality. The low-level current flows to the conduction switch KY1, keeping the conduction switch KY1 closed, and the security battery works normally.

[0085] When the output level is high, it indicates that the security battery connection circuit is abnormal, and there is a situation of reverse connection or no connection. At this time, the output terminal 8 is at a high level, and the high-level current conducts the fourth transistor Q4 and no longer flows to the conduction switch KY1. The conduction switch KY1 is opened, realizing the disconnection protection of the security battery.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A reverse connection and disconnection detection circuit for security batteries, characterized in that, It includes a power line (1) for charging or discharging the security battery and a detection protection line (2) for detecting whether the security battery is reverse connected or not connected. The power line (1) and the detection protection line (2) are respectively connected to BAT+ and BAT- of the security battery, and BAT- is grounded. A conduction switch (KY1) is provided in the power line (1). The detection protection line (2) includes a protection line (21) and a detection line (22). The detection line (22) is provided with a connection unit (221), a comparison unit (222), and a control unit (223). The detection protection line (2) is grounded. One end of the control unit (223) is connected to the comparison unit (222) to receive voltage signals, and the other end is connected to the control circuit of the on switch (KY1); the control unit (223) controls the control circuit, thereby controlling the on or off of the on switch (KY1), and finally controlling the on or off of the power supply line (1); The comparison unit (222) includes a third unidirectional conducting element (D3), a sixth resistor (R6), a seventh resistor (R7), an eighth resistor (R8), a ninth resistor (R9), and an amplifier (U1); the amplifier (U1) is provided with a second input terminal (10), a first input terminal (9), and an output terminal (8); the output terminal (8) is connected to the control unit (223), the second input terminal (10) is connected to the sixth resistor (R6), and the sixth resistor (R6) is connected in series with the third unidirectional conducting element (D3) and then connected to the protection circuit (21); the seventh resistor (R9) is connected to the third unidirectional conducting element (D3), the sixth resistor (R6) is connected in series with the third unidirectional conducting element (D3), and then connected to the protection circuit (21); the seventh resistor (R9) is connected in series with ... the seventh resistor (R7), the eighth resistor (R8), the ninth resistor (R9), and the ninth resistor (R9). One end of resistor (R7) is connected to the connection unit (221), and the other end is connected to the sixth resistor (R6) and in parallel to the second input terminal (10) of the amplifier (U1); the eighth resistor (R8) and the ninth resistor (R9) are connected to the first input terminal (9), and the eighth resistor (R8) is connected to an external auxiliary positive voltage; the ninth resistor (R9) is connected to the connection unit (221), and the output terminal (8) is connected to the control unit (223); the seventh resistor (R7), the ninth resistor (R9), and the connection unit (221) share a common ground. The control unit (223) includes an eleventh resistor (R11), a twelfth resistor (R12), a third transistor (Q3), and a thirteenth resistor (R13). The third transistor (Q3) has a first pin (Q31), a second pin (Q32), and a third pin (Q33). One end of the eleventh resistor (R11) is connected to the comparator unit (222), and the other end is connected to the third pin (Q33) of the third transistor (Q3). One end of the twelfth resistor (R12) is grounded with the connection unit (221), and the other end is connected to the third pin (Q33) of the third transistor (Q3), and is connected in parallel with the eleventh resistor (R11). The second pin (Q32) of the third transistor (Q3) is connected to the thirteenth resistor (R13), and an external auxiliary positive voltage is connected through the thirteenth resistor (R13). A connection port is provided outward between the thirteenth resistor (R13) and the second pin (Q32) of the third transistor (Q3).

2. The reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The protection circuit (21) includes a pressure-reducing unidirectional conducting element (D1), a first resistor (R1), a first transistor (Q1), and a second unidirectional conducting element (D2); wherein the first transistor (Q1) is provided with a first pin (Q11), a second pin (Q12), and a third pin (Q13); the pressure-reducing unidirectional conducting element (D1) is connected to BAT+, and is connected in series with the first resistor (R1), and is also connected to the first pin (Q11) of the first transistor (Q1); the second pin (Q12) of the first transistor (Q1) is connected to the second unidirectional conducting element (D2), and the other end of the second unidirectional conducting element (D2) is connected to BAT-; the third pin (Q13) of the first transistor (Q1) is connected outward to the connection unit (221); the second unidirectional conducting element (D2) is used to prevent reverse battery discharge when the security battery is reverse connected; the detection circuit (22) is connected in parallel to the side of the second unidirectional conducting element (D2) near BAT-.

3. The reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The connection unit (221) includes a second resistor (R2), a third resistor (R3), a second transistor (Q2), a fourth resistor (R4), and a fifth resistor (R5). The second transistor (Q2) has a first pin (Q21), a second pin (Q22), and a third pin (Q23). One end of the second resistor (R2) is connected in series with the third resistor (R3) to the second pin (Q22) of the second transistor (Q2), and the other end is connected to the protection line (21). The protection line (21) is connected between the second resistor (R2) and the third resistor (R3), forming a parallel connection with the second resistor (R2). The third pin (Q23) of the second transistor (Q2) is connected to the fourth resistor (R4) and extends outward to the normally closed open port (BAT-NC). The fifth resistor (R5) is connected between the first pin (Q21) and the third pin (Q23) of the second transistor (Q2), and the fifth resistor (R5) shares a common ground with the second transistor (Q2).

4. The reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, A third capacitor (C3) and a tenth resistor (R10) are connected between the output terminal (8) and the first input terminal (9), and the third capacitor (C3) and the tenth resistor (R10) are connected in series.

5. A reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The amplifier (U1) has a fourth capacitor (C4) and an external positive voltage (VCC) connected in parallel. The fourth capacitor (C4) is connected to both sides of the second input terminal (10) and the first input terminal (9). The fourth capacitor (C4) and the first input terminal (9) are grounded.

6. The reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The third transistor (Q3) is connected to an external connection port connected to an MCU. The MCU is connected to the control circuit of the on switch (KY1) in the power line (1), and the MCU controls the on switch (KY1) to be turned on or off.

7. A reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The control unit (223) includes a fourteenth resistor (R14), a fifteenth resistor (R15), a fourth unidirectional conducting element (D4), and a fourth transistor (Q4); wherein the fourth transistor (Q4) is provided with a first pin (Q41), a second pin (Q42), and a third pin (Q43); one end of the fourteenth resistor (R14) is connected in parallel with the fifteenth resistor (R15) to the comparator unit (222), and the other end is connected in series with the fourth unidirectional conducting element (D4). The control circuit is connected to the on switch (KY1), and the on switch (KY1) is closed or opened by the conduction or non-conduction of the control circuit; the other end of the fifteenth resistor (R15) is connected to the first pin (Q41) of the fourth transistor (Q4); the third pin (Q43) of the fourth transistor (Q4) is grounded, and the second pin (Q42) is connected to a normally closed open port (BAT-NC).

8. A reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The power supply line (1) includes a charging line (11) for charging the security battery and a discharging line (12) for discharging the security battery, wherein, The charging line (11) is provided with a first charging capacitor (C1), a second charging capacitor (C2), a switching switch (KY1), and a one-way charging element (D5); the first charging capacitor (C1), the second charging capacitor (C2), and the one-way charging element (D5) are connected in parallel to each other, and are all connected to BAT+ and BAT-, and are connected in series with the switching switch (KY1); the switching switch (KY1) is provided with a winding coil, and the two ends of the winding coil extend outward to connect to the control line, and the control line is connected to the control unit (223). The discharge circuit (12) is provided with a discharge capacitor (C5), a first discharge transistor (Q5), a second discharge transistor (Q6), and a sixteenth resistor (R16); wherein the first discharge transistor (Q5) is provided with a first pin (Q51), a second pin (Q52), and a third pin (Q53), and the second discharge transistor (Q6) is provided with a first pin (Q61), a second pin (Q62), and a third pin (Q63); one end of the discharge capacitor (C5) is connected to BAT+, the second pin (Q52) of the first discharge transistor (Q5) is connected in parallel to the charging unidirectional conduction element (D5); the second pin (Q62) of the second discharge transistor (Q6) is connected to the conduction switch (KY1), the sixteenth resistor (R16) is connected to the third pin (Q63) of the second discharge transistor (Q6), and the discharge capacitor (C5), the sixteenth resistor (R16), and the first pin (Q61) of the second discharge transistor (Q6) share a common ground.

9. A reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The on / off switch (KY1) is a relay, which is controlled according to the electrical signal of the control unit (223).

10. A reverse connection and disconnection detection circuit for a security battery according to claim 1, characterized in that, The sixth resistor (R6) and the seventh resistor (R7), the eighth resistor (R8) and the ninth resistor (R9) are all set with resistance values ​​in proportion. The ratio of the eighth resistor (R8) and the ninth resistor (R9) is set by setting the voltage of the first input terminal (9). The ratio of the sixth resistor (R6) and the seventh resistor (R7) determines the voltage of the second input terminal (10).

11. A detection method for a reverse connection and disconnection detection circuit for a security battery, as described in any one of claims 1-10, characterized in that, The detection method is as follows: When the power line (1) is turned on, the amplifier (U1) will have different output levels at the output terminal (8) due to the voltage difference between the second input terminal (10) and the first input terminal (9). There are two different situations. At this time, the different output levels will control the on switch (KY1) differently. When the output terminal (8) is at a low level, the current flows to the control unit (223), then to the MCU and then to the control line or directly to the control line. At this time, the MCU detects a high level and controls the control line. The control line controls the on switch (KY1) to turn on the on switch (KY1), and the power line (1) remains on. When the output level is high, the current flows to the control unit (223), turns on the third transistor (Q3) or the fourth transistor (Q4), and no longer flows to the MCU or control line. The connected MCU detects the low level, and the control line is not turned on, causing the on switch (KY1) to not turn on, thereby disconnecting the power line (1) for protection.

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