Isolation type reverse connection prevention circuit and new energy battery

Abstract

The utility model provides an isolation type reverse connection prevention circuit and a new energy battery, the isolation type reverse connection prevention circuit comprises a reverse connection identification circuit, a protection driving circuit and a control circuit, the reverse connection identification circuit comprises a first diode, an optocoupler, a first resistor and a second resistor, the protection driving circuit comprises a third resistor, a fourth resistor, a fifth resistor, a seventh resistor, a third diode, a fourth diode, a first transistor and a second transistor, the control circuit comprises an eighth resistor and a field effect transistor, when a power supply is positively connected, the optocoupler is not conducted, then the protection driving circuit does not work, and power consumption is low; when the power supply is reversely connected, current passes through the reverse connection identification circuit, the optocoupler is conducted, so that the protection driving circuit works, the first transistor is conducted, the short-circuit signal end is pulled to a low level, the MCU identifies the low level and then enables a signal to conduct the second transistor, then the level of the control end of the field-effect tube is pulled down, and the field-effect tube is turned off. And a battery end loop can be quickly cut off.

Description

Technical Field

[0001] The present disclosure relates to the technical field of new energy batteries, and in particular to an isolated anti-reverse connection circuit and a new energy battery. Background Art

[0002] With the development of new energy in recent years, new energy batteries have gradually become popular in daily life, and people have increasingly stringent requirements on the safety functions of new energy batteries. For example, new energy batteries usually need to be designed with reverse connection protection. If this function is not available, serious safety accidents may occur when the battery external power supply is reversed, endangering the safety of users.

[0003] There are many reverse connection protection technologies currently used in the market, and some of them are relatively simple, mainly adding two diodes (D38, D39) at the external interface. When the external power supply is reversed, the diodes directly short-circuit the external power supply. Figure 1 As shown, this circuit is particularly dependent on the short-circuit protection of the external power supply itself. If there is a problem with the short-circuit protection of the external power supply or there is no short-circuit protection, a safety accident may occur.

[0004] To solve the above problems, a Chinese patent with publication number CN203553933U discloses a circuit for battery isolation reverse connection protection, including an MCU controller, an input polarity discrimination circuit, a battery voltage feedback circuit, a reverse isolation MOS tube drive circuit, a reverse isolation MOS tube circuit, a charging MOS tube drive circuit and a charging MOS tube circuit. The input polarity discrimination circuit is connected to the positive electrode of the battery via the reverse isolation MOS tube circuit, the charging MOS tube circuit and the battery voltage feedback circuit in sequence. The input polarity discrimination circuit and the battery voltage feedback circuit respectively feed back feedback signals to the MCU controller, and the MCU controller controls the reverse isolation MOS tube drive circuit and the charging MOS tube drive circuit according to the feedback signals.

[0005] Although the above circuit can achieve isolation reverse connection protection through MOS tube isolation circuit and solve the problem of easy battery damage by driving signal, it has certain power consumption and high cost because of the design of multiple photocouplers.

[0006] How to effectively implement a protection circuit for reverse connection protection and short circuit protection that does not rely on an external power supply and has low power consumption is still a problem that needs to be solved. Utility Model Content

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an isolated anti-reverse connection circuit and a new energy battery with low power consumption and fast reverse connection protection.

[0008] The purpose of this disclosure is achieved through the following technical solutions:

[0009] An isolated anti-reverse connection circuit, comprising:

[0010] A reverse connection identification circuit comprises a first diode, an optical coupler, a first resistor and a second resistor, wherein the positive electrode of the first diode is connected to the negative electrode of a power supply, the negative electrode of the first diode is connected to the positive electrode of the power supply through the first resistor and the second resistor in sequence, the first end of the second resistor is connected to the first end of the optical coupler, and the second end of the second resistor is connected to the second end of the optical coupler;

[0011] A protection driving circuit, comprising a third resistor, a fourth resistor, a fifth resistor, a seventh resistor, a third diode, a fourth diode, a first transistor and a second transistor, wherein the fourth end of the optical coupler is connected to a reference power supply through the third resistor, the third end of the optical coupler is connected to a control end of the first transistor, the third end of the optical coupler is also connected to a negative electrode of a battery through the fourth resistor, the first end of the fifth resistor is connected to a reference power supply, the second end of the fifth resistor is connected to a short-circuit signal end and connected to a first end of the first transistor, the second end of the first transistor is connected to the negative electrode of the battery, the first end of the seventh resistor is connected to a signal enable end, the second end of the seventh resistor is connected to an anode of the third diode, the cathode of the third diode is connected to a first end of the first transistor, the first end of the seventh resistor is also connected to an anode of the fourth diode, the cathode of the fourth diode is connected to a first end of the second transistor, the second end of the second transistor is connected to the negative electrode of the battery, and the control end of the second transistor is connected to an anode of the third diode;

[0012] The control circuit includes an eighth resistor and a field effect tube, wherein the control end of the field effect tube is connected to the cathode of the fourth diode through the eighth resistor, the first end of the field effect tube is connected to the cathode of the battery, and the second end of the field effect tube is connected to the cathode of the power supply.

[0013] In one embodiment, the reverse connection identification circuit further includes a voltage-stabilizing capacitor, an upper half of the voltage-stabilizing capacitor is connected to the first end of the second resistor, and a lower half of the voltage-stabilizing capacitor is connected to the second end of the second resistor.

[0014] In one embodiment, the protection driving circuit further includes a second diode, an anode of the second diode is connected to the second end of the fifth resistor, and a cathode of the second diode is connected to the first end of the first transistor.

[0015] In one embodiment, the protection driving circuit further includes a sixth resistor, and the control end of the second transistor is connected to the negative electrode of the battery through the sixth resistor.

[0016] In one embodiment, the sixth resistor is a variable resistor.

[0017] In one embodiment, the protection driving circuit further includes a voltage regulator diode, wherein an anode of the voltage regulator diode is connected to the second end of the second transistor, and a cathode of the voltage regulator diode is connected to the first end of the second transistor.

[0018] In one of the embodiments, the model of the Zener diode is TL7705.

[0019] In one embodiment, at least one of the first resistor and the second resistor is a variable resistor.

[0020] In one embodiment, the fourth resistor is a variable resistor.

[0021] A new energy battery comprises the isolated anti-reverse connection circuit described in any embodiment.

[0022] Compared with the prior art, the present invention has at least the following advantages:

[0023] When the power supply is connected positively, the current passing through the reverse connection identification circuit of the above-mentioned isolated anti-reverse connection circuit is extremely small, and the optocoupler is not turned on, thereby preventing the protection drive circuit from working and consuming low power. When the power supply is connected reversely, current passes through the reverse connection identification circuit, turning on the optocoupler, causing the protection drive circuit to work, first turning on the first transistor, and the short-circuit signal end is pulled to a low level. After the MCU recognizes the low level, the enable signal turns on the second transistor, and then the control end level of the field effect tube is pulled low, and the field effect tube is turned off. In this way, the battery end loop can be quickly cut off, and the short-circuit protection of the external power supply itself is no longer relied on. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A circuit diagram in the prior art;

[0026] Figure 2 FIG. 4 is a circuit diagram of an isolated anti-reverse connection circuit according to an embodiment.

[0027] : 10, isolated reverse connection circuit; 100, reverse connection identification circuit; 200, protection drive circuit; 300, control circuit; DS1, first diode; DS2, second diode; DS3, third diode; DS4, fourth diode; DZ1, voltage-stabilizing diode; GU1, optocoupler; CP1, voltage-stabilizing capacitor; M1, field-effect transistor; QU1, first transistor; QU2, second transistor; RK1, first resistor; RK2, second resistor; RK3, third resistor; RK4, fourth resistor; RK5, fifth resistor; RK6, sixth resistor; RK7, seventh resistor; RK8, eighth resistor. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0029] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0031] The present invention discloses an isolated anti-reverse connection circuit, including a reverse connection identification circuit, a protection drive circuit and a control circuit. The reverse connection identification circuit includes a first diode, an optical coupler, a first resistor and a second resistor. The positive electrode of the first diode is connected to the negative electrode of a power supply, and the negative electrode of the first diode is connected to the positive electrode of the power supply through the first resistor and the second resistor in sequence. The first end of the second resistor is connected to the first end of the optical coupler, and the second end of the second resistor is connected to the second end of the optical coupler. The protection drive circuit includes a third resistor, a fourth resistor, a fifth resistor, a seventh resistor, a third diode, a fourth diode, a first transistor and a second transistor. The fourth end of the optical coupler is connected to a reference power supply through the third resistor, the third end of the optical coupler is connected to the control end of the first transistor, the third end of the optical coupler is also connected to the negative electrode of a battery through the fourth resistor, and the first end of the fifth resistor is connected to the reference power supply through the third resistor. The reference power supply is terminated, the second end of the fifth resistor is connected to the short-circuit signal end and connected to the first end of the first transistor, the second end of the first transistor is connected to the negative electrode of the battery, the first end of the seventh resistor is connected to the signal enable end, the second end of the seventh resistor is connected to the positive electrode of the third diode, the negative electrode of the third diode is connected to the first end of the first transistor, the first end of the seventh resistor is also connected to the positive electrode of the fourth diode, the negative electrode of the fourth diode is connected to the first end of the second transistor, the second end of the second transistor is connected to the negative electrode of the battery, and the control end of the second transistor is connected to the positive electrode of the third diode; the control circuit includes an eighth resistor and a field effect transistor, the control end of the field effect transistor is connected to the negative electrode of the fourth diode through the eighth resistor, the first end of the field effect transistor is connected to the negative electrode of the battery, and the second end of the field effect transistor is connected to the negative electrode of the power supply.

[0032] When the power supply is connected positively, the current passing through the reverse connection identification circuit of the above-mentioned isolated anti-reverse connection circuit is extremely small, and the optocoupler is not turned on, thereby preventing the protection drive circuit from working and consuming low power. When the power supply is connected reversely, current passes through the reverse connection identification circuit, turning on the optocoupler, causing the protection drive circuit to work, first turning on the first transistor, and the short-circuit signal end is pulled to a low level. After the MCU recognizes the low level, the enable signal turns on the second transistor, and then the control end level of the field effect tube is pulled low, and the field effect tube is turned off. In this way, the battery end loop can be quickly cut off, and the short-circuit protection of the external power supply itself is no longer relied on.

[0033] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0034] like Figure 2 As shown, an isolated anti-reverse connection circuit 10 according to an embodiment includes a reverse connection identification circuit 100 , a protection driving circuit 200 and a control circuit 300 .

[0035] The reverse connection identification circuit 100 includes a first diode DS1, an optical coupler GU1, a first resistor RK1 and a second resistor RK2, wherein the anode of the first diode DS1 is connected to the cathode of the power supply, the cathode of the first diode DS1 is connected to the cathode of the power supply through the first resistor RK1 and the second resistor RK2 in sequence, the first end of the second resistor RK2 is connected to the first end of the optical coupler GU1, and the second end of the second resistor RK2 is connected to the second end of the optical coupler GU1;

[0036] The protection driving circuit 200 includes a third resistor RK3, a fourth resistor RK4, a fifth resistor RK5, a seventh resistor RK7, a third diode DS3, a fourth diode DS4, a first transistor QU1 and a second transistor QU2. The fourth end of the optical coupler GU1 is connected to the reference power supply through the third resistor RK3, the third end of the optical coupler GU1 is connected to the control end of the first transistor QU1, the third end of the optical coupler GU1 is also connected to the negative electrode of the battery through the fourth resistor RK4, the first end of the fifth resistor RK5 is connected to the reference power supply, the second end of the fifth resistor RK5 is connected to the short-circuit signal end SHORT and connected to the first end of the first transistor QU1, wherein when SHORT is at a high level, it indicates that the power supply is normal, otherwise, it indicates that The power supply is reversed, the second end of the first transistor QU1 is connected to the negative electrode of the battery, the first end of the seventh resistor RK7 is connected to the signal enable end, specifically, the signal enable end is ON_DSG1, which is used to enable the signal when the power supply is short-circuited and the MCU recognizes that SHORT is at a low level, the second end of the seventh resistor RK7 is connected to the positive electrode of the third diode DS3, the negative electrode of the third diode DS3 is connected to the first end of the first transistor QU1, the first end of the seventh resistor RK7 is also connected to the positive electrode of the fourth diode DS4, the negative electrode of the fourth diode DS4 is connected to the first end of the second transistor QU2, the second end of the second transistor QU2 is connected to the negative electrode of the battery, and the control end of the second transistor QU2 is connected to the positive electrode of the third diode DS3;

[0037] The control circuit 300 includes an eighth resistor RK8 and a field effect transistor M1. The control end of the field effect transistor M1 is connected to the cathode of the fourth diode DS4 through the eighth resistor RK8. The first end of the field effect transistor M1 is connected to the cathode of the battery. The second end of the field effect transistor M1 is connected to the cathode of the power supply.

[0038] Specifically, when the power supply is connected forwardly, the power supply current flows from the positive electrode of the power supply through the negative electrode of the power supply. At this time, the resistance of the first diode DS1 is infinite, the optocoupler GU1 is not turned on, and the protection drive circuit 200 does not work; when the power supply is connected reversely, the current passes through the first diode DS1, the first resistor RK1 to the optocoupler GU1 in sequence, and the first and second ends of the optocoupler GU1 have current passing through, thereby turning on the third and fourth ends of the optocoupler GU1. The current of the reference power supply passes through the third resistor RK3, the optocoupler GU1 and the fourth resistor RK4 in sequence and is connected to the negative electrode of the battery. The current passes through the control end of the first transistor QU1, pulling the control end to a high level. , thereby turning on the first transistor QU1, and the current of the other reference power supply passes through the fifth resistor RK5 and the first transistor QU1 in sequence and is connected to the negative electrode of the battery. The level of the short-circuit signal terminal SHORT is pulled low. After the control unit (MCU) recognizes the low level, it enables the ON_DSG1 signal to the protection drive circuit 200, and the current passes through the seventh resistor RK7 and the fourth diode DS4 in sequence. The control end level of the second transistor QU2 is pulled low, and then it is turned on to the negative electrode of the battery. At the same time, the level of the control end of the field effect tube M1 is pulled low, and then the field effect tube M1 is turned off to prevent the external power supply from damaging the battery BMS.

[0039] In this embodiment, the first and second ends of the optical coupler GU1 constitute an internal diode, and the third and fourth ends constitute a photo-controlled thyristor; the first transistor QU1 and the second transistor QU2 are respectively an NPN-type triode and a PNP-type triode, the first end of the first transistor QU1 is a collector, the second end is an emitter, and the control end is a base, the first end of the second transistor QU2 is an emitter, the second end is a collector, and the control end is a base; the field effect transistor M1 is an NMOS transistor, the control end of the field effect transistor M1 is a gate, the first end is a source, and the second end is a drain. The following embodiments can be explained.

[0040] In one embodiment, the reverse connection identification circuit 100 further includes a voltage-stabilizing capacitor CP1, the upper half of which is connected to the first end of the second resistor RK2, and the lower half of which is connected to the second end of the second resistor RK2. In this embodiment, the first resistor RK1 is connected in series with the voltage-stabilizing capacitor CP1, and the second resistor RK2 is connected in parallel with the voltage-stabilizing capacitor CP1, so that filtering can be performed to reduce interference from excessive signals; on the other hand, the voltage-stabilizing capacitor CP1 can stabilize the voltage at the first end of the second resistor RK2, reducing the possibility of sudden voltage changes.

[0041] In one embodiment, the protection driving circuit 200 further includes a second diode DS2, and the fifth resistor RK5 is connected to the first end of the first transistor QU1 through the second diode DS2. Specifically, the anode of the second diode DS2 is connected to the second end of the fifth resistor RK5, and the cathode of the second diode DS2 is connected to the first end of the first transistor QU1. The second diode DS2 can prevent the current in the reference voltage from flowing back, so that the current flows through the negative electrode of the battery after passing through the fifth resistor RK5, the second diode DS2 and the first transistor QU1 in sequence and does not flow in the reverse direction, thereby avoiding damage to the first transistor QU1 due to current backflow.

[0042] In one embodiment, the protection driving circuit 200 further includes a sixth resistor RK6, and the control end of the second transistor QU2 is connected to the negative electrode of the battery through the sixth resistor RK6. Further, the sixth resistor RK6 can divide the control end of the second transistor QU2 to provide a conduction condition for the second transistor QU2, and further ensure that the field effect transistor M1 is turned off when the second transistor QU2 is turned on.

[0043] In one embodiment, the sixth resistor RK6 is a variable resistor. Further, when the sixth resistor RK6 is a variable resistor, the conduction condition of the second transistor QU2 can be adjusted by adjusting the resistance of the sixth resistor RK6 to adapt to more types of second transistors QU2.

[0044] In one embodiment, the protection driving circuit 200 further includes a voltage stabilizing diode DZ1, wherein the positive electrode of the voltage stabilizing diode DZ1 is connected to the second end of the second transistor QU2, and the negative electrode of the voltage stabilizing diode DZ1 is connected to the first end of the second transistor QU2. Furthermore, the voltage stabilizing diode DZ1 stabilizes the field effect transistor M1, thereby preventing the gate-source voltage (Vgs) of the field effect transistor M1 from being too large and thus damaging the field effect transistor M1.

[0045] In one embodiment, the model of the Zener diode DZ1 is TL7705. In other embodiments, the model of the Zener diode DZ1 is one of 1N4728, SMA4728A, and SMC5338B.

[0046] In one embodiment, at least one of the first resistor RK1 and the second resistor RK2 is a variable resistor. Furthermore, the resistance of the first resistor RK1 or the second resistor RK2 can be adjusted to control the current flowing from the negative electrode of the power supply through the positive electrode of the power supply, thereby reducing the possibility of damaging the circuit due to excessive current.

[0047] In one embodiment, the fourth resistor RK4 is a variable resistor. Further, when the fourth resistor RK4 is a variable resistor, the conduction condition of the first transistor QU1 can be adjusted by adjusting the resistance of the fourth resistor RK4 to adapt to more models of the first transistor QU1.

[0048] The present disclosure further provides a new energy battery, comprising the isolated anti-reverse connection circuit 10 of any embodiment.

[0049] Compared with the prior art, the present invention has at least the following advantages:

[0050] When the power supply of the above-mentioned isolated anti-reverse connection circuit 10 is positively connected, the current passing through the reverse connection identification circuit 100 is extremely small, and the optocoupler GU1 is not turned on, thereby protecting the drive circuit 200 from working, and the power consumption is low; when the power supply is reversely connected, current passes through the reverse connection identification circuit 100, turning on the optocoupler GU1, so that the protection drive circuit 200 works, first turning on the first transistor QU1, and the short-circuit signal terminal SHORT is pulled to a low level. After the MCU recognizes the low level, the enable signal turns on the second transistor QU2, and then the control terminal level of the field effect transistor M1 is pulled low, and the field effect transistor M1 is turned off. In this way, the battery end loop can be quickly cut off, and no longer rely on the short-circuit protection of the external power supply itself.

[0051] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. An isolated anti-reverse connection circuit, characterized in that: include: A reverse connection identification circuit comprises a first diode, an optical coupler, a first resistor and a second resistor, wherein the positive electrode of the first diode is connected to the negative electrode of a power supply, the negative electrode of the first diode is connected to the positive electrode of the power supply through the first resistor and the second resistor in sequence, the first end of the second resistor is connected to the first end of the optical coupler, and the second end of the second resistor is connected to the second end of the optical coupler; A protection driving circuit, comprising a third resistor, a fourth resistor, a fifth resistor, a seventh resistor, a third diode, a fourth diode, a first transistor and a second transistor, wherein the fourth end of the optical coupler is connected to a reference power supply through the third resistor, the third end of the optical coupler is connected to a control end of the first transistor, the third end of the optical coupler is also connected to a negative electrode of a battery through the fourth resistor, the first end of the fifth resistor is connected to a reference power supply, the second end of the fifth resistor is connected to a short-circuit signal end and connected to a first end of the first transistor, the second end of the first transistor is connected to the negative electrode of the battery, the first end of the seventh resistor is connected to a signal enable end, the second end of the seventh resistor is connected to an anode of the third diode, the cathode of the third diode is connected to a first end of the first transistor, the first end of the seventh resistor is also connected to an anode of the fourth diode, the cathode of the fourth diode is connected to a first end of the second transistor, the second end of the second transistor is connected to the negative electrode of the battery, and the control end of the second transistor is connected to an anode of the third diode; The control circuit includes an eighth resistor and a field effect tube, wherein the control end of the field effect tube is connected to the cathode of the fourth diode through the eighth resistor, the first end of the field effect tube is connected to the cathode of the battery, and the second end of the field effect tube is connected to the cathode of the power supply.

2. The isolated anti-reverse connection circuit according to claim 1, characterized in that: The reverse connection identification circuit further includes a voltage stabilizing capacitor, an upper end of the voltage stabilizing capacitor is connected to the first end of the second resistor, and a lower end of the voltage stabilizing capacitor is connected to the second end of the second resistor.

3. The isolated anti-reverse connection circuit according to claim 1, characterized in that: The protection driving circuit further includes a second diode, an anode of the second diode is connected to the second end of the fifth resistor, and a cathode of the second diode is connected to the first end of the first transistor.

4. The isolated anti-reverse connection circuit according to claim 1, characterized in that: The protection driving circuit further includes a sixth resistor, and the control end of the second transistor is connected to the negative electrode of the battery through the sixth resistor.

5. The isolated anti-reverse connection circuit according to claim 4, characterized in that: The sixth resistor is a variable resistor.

6. The isolated anti-reverse connection circuit according to claim 1, characterized in that: The protection driving circuit further includes a voltage regulator diode, wherein an anode of the voltage regulator diode is connected to the second end of the second transistor, and a cathode of the voltage regulator diode is connected to the first end of the second transistor.

7. The isolated anti-reverse connection circuit according to claim 6, characterized in that: The model of the voltage stabilizing diode is TL7705.

8. The isolated anti-reverse connection circuit according to claim 1, characterized in that: At least one of the first resistor and the second resistor is a variable resistor.

9. The isolated anti-reverse connection circuit according to claim 1, characterized in that: The fourth resistor is a variable resistor.

10. A new energy battery, characterized in that: The invention comprises the isolated anti-reverse connection circuit as described in any one of claims 1 to 9.

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