CN217087762U

CN217087762U - Voltage detection circuit, vehicle emergency starting power supply and battery clamp

Info

Publication number: CN217087762U
Application number: CN202122748820.7U
Authority: CN
Inventors: 雷云; 张智锋; 林建平
Original assignee: Shenzhen Carku Technology Co Ltd
Current assignee: Shenzhen Carku Technology Co Ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-07-29
Anticipated expiration: 2031-11-10

Abstract

The application provides a voltage detection circuit, emergent start power of vehicle and storage battery presss from both sides, voltage detection circuit includes voltage detection module, processing module and switch module, voltage detection module is connected with the first positive pole and the first negative pole electricity of vehicle storage battery respectively, a voltage for detecting between first positive pole and the first negative pole, and obtain the detected signal according to the voltage between first positive pole and the first negative pole, switch module is connected with processing module and first negative pole electricity respectively, processing module is used for the on-state according to detected signal control switch module. The switch module is electrically connected with the first negative pole and used for controlling a loop where the first negative pole is located, and the voltage detection module is used for detecting a voltage value between the first positive pole and the first negative pole. The processing module can control a loop where the first cathode is located according to the voltage between the first electrode and the second electrode, and automatic logic control is achieved.

Description

Voltage detection circuit, vehicle emergency starting power supply and battery clamp

Technical Field

The application relates to the technical field of circuits, in particular to a voltage detection circuit, a vehicle emergency starting power supply and a battery clamp.

Background

Vehicles have long been one of the important vehicles for humans. At present, the emergent start power supply products of vehicle on the market mostly adopt the anodal switch mode of closed circuit, and the switch module of this kind of switch mode need use more electronic components, has with high costs problem.

SUMMERY OF THE UTILITY MODEL

The application discloses voltage detection circuit can solve with high costs technical problem.

In a first aspect, the present application provides a voltage detection circuit, where the voltage detection circuit includes a voltage detection module, a processing module, a switch module, and a load port, where the load port includes a first positive electrode and a first negative electrode, and the voltage detection module includes an isolation sensing unit; wherein,

the voltage detection module is respectively electrically connected with the first positive electrode and the first negative electrode, and is used for detecting the voltage between the first positive electrode and the first negative electrode and obtaining a detection signal according to the voltage between the first positive electrode and the first negative electrode;

the switch module is electrically connected with the processing module and the first negative electrode respectively;

the processing module is used for controlling the conducting state of the switch module according to the detection signal.

The switch module is electrically connected with the first negative electrode and used for controlling a loop of the first negative electrode, and the voltage detection module is used for detecting a voltage value between the first positive electrode and the first negative electrode. The processing module can control a loop where the first cathode is located according to the voltage between the first electrode and the second electrode, so that automatic logic control is realized.

Optionally, the voltage detection circuit further includes a power supply terminal, the switch module is further configured to be electrically connected to a second negative electrode of the power supply terminal, the first positive electrode is electrically connected to a second positive electrode of the power supply terminal, wherein,

when the switch module is turned on, the first negative electrode can be electrically connected with the second negative electrode through the switch module, so that the power supply end can supply power for the output of the load port.

Optionally, the isolation sensing unit includes a signal transmitting unit and a signal receiving unit, the signal transmitting unit is electrically connected to the first positive electrode and the first negative electrode, and the signal receiving unit is electrically connected to the processing module; wherein,

the signal transmitting unit is used for generating a signal which can be received by the signal receiving unit in a non-electric coupling mode based on the voltages of the first positive pole and the first negative pole, and the signal receiving unit is used for sending the detection signal to the processing module based on the signal received from the signal transmitting unit.

Optionally, the negative electrode of the signal receiving unit and the ground terminal of the processing module are both electrically connected to one end of the switch module, and the negative electrode of the signal transmitting unit and the first negative electrode are electrically connected to the other end of the switch module.

Optionally, the voltage detection module includes a light emitting unit and a light sensing unit, the light emitting unit is electrically connected to the first anode and the first cathode respectively, and the light sensing unit is electrically connected to the processing module; wherein,

the light emitting unit is used for sending an optical signal based on the voltage between the first positive electrode and the first negative electrode;

the photosensitive unit is used for receiving the optical signal and generating the detection signal based on the optical signal.

Optionally, the voltage detection circuit further includes a driving module, the driving module is electrically connected to the processing module and the switch module, respectively, and the processing module is further configured to send a control signal to the driving module to drive the switch module to be turned on.

Optionally, the switch module includes a plurality of NMOS transistors.

Optionally, when the processing module detects that the voltage value between the first positive electrode and the first negative electrode is greater than 0V, the processing module outputs a control signal to turn on the switch module through the control signal.

Optionally, when the processing module detects that the voltage value between the first positive electrode and the first negative electrode is greater than or equal to a preset voltage threshold, the processing module outputs a control signal to turn on the switch module through the control signal.

Optionally, when the processing module detects that the voltage value between the first positive electrode and the first negative electrode decreases, or the decrease rate reaches a preset decrease rate, the processing module outputs a control signal to turn on the switch module through the control signal.

Optionally, the voltage detection circuit further includes a power supply module, the power supply module is electrically connected to the processing module and the second positive electrode respectively, and the power supply module is configured to supply power to the processing module.

In a second aspect, the present application further provides an emergency starting power supply for a vehicle, the emergency starting power supply includes the voltage detection circuit according to the first aspect and a power supply, and the power supply provides voltage/current for the power supply end.

In a third aspect, the present application further provides a battery clamp, which includes a housing and the voltage detection circuit according to the first aspect, wherein at least a part of the voltage detection circuit is disposed in the housing.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for a person skilled in the art to obtain other drawings based on the drawings without any inventive exercise.

Fig. 1 is a schematic diagram of a voltage detection circuit framework according to an embodiment of the present disclosure.

Fig. 2 is a schematic circuit diagram of a voltage detection module according to an embodiment of the present disclosure.

Fig. 3 is a schematic circuit diagram of a voltage detection module according to an embodiment of the present disclosure.

Fig. 4 is a circuit diagram of a switch module and a driving module according to an embodiment of the present disclosure.

Fig. 5 is a schematic diagram of a voltage detection circuit according to an embodiment of the present disclosure.

Fig. 6 is a schematic view of a vehicle emergency starting power supply device according to an embodiment of the present application.

Fig. 7 is a schematic view of a battery clamp according to an embodiment of the present disclosure.

Description of reference numerals: the intelligent battery clamp comprises a detection signal-CAR _ AD, a control signal-Mos _ EN, a voltage detection circuit-1, a voltage detection module-11, an isolation sensing unit-111, a signal transmitting unit-1111, a signal receiving unit-1112, a light emitting unit-112, a light sensing unit-113, a load port-12, a first positive electrode 121, a first negative electrode 122, a processing module-13, a switch module-14, a power supply end-15, a second positive electrode-151, a second negative electrode-152, a driving module-16, a power supply module-17, a vehicle emergency starting power supply 2, a power supply-21, a battery clamp-3, a shell-31 and an intelligent battery clamp-32.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the embodiments in the present application are within the scope of protection of the present application.

Reference to "electrically connected" in embodiments of the present application may include direct electrical connection or indirect electrical connection, and "connected" may include direct connection or indirect connection.

Referring to fig. 1, fig. 1 is a schematic diagram of a voltage detection circuit 1 according to an embodiment of the present disclosure. The voltage detection circuit 1 comprises a voltage detection module 11, a processing module 13, a switch module 14 and a load port 12, wherein the load port 12 comprises a first positive electrode 121 and a first negative electrode 122, and the voltage detection module 11 comprises an isolation sensing unit 111; the voltage detection module 11 is electrically connected to the first positive electrode 121 and the first negative electrode 122, and is configured to detect a voltage between the first positive electrode 121 and the first negative electrode 122, and obtain a detection signal CAR _ AD according to the voltage between the first positive electrode 121 and the first negative electrode 122; the switch module 14 is electrically connected to the processing module 13 and the first cathode 122, respectively; the processing module 13 is configured to control the conducting state of the switch module 14 according to the detection signal CAR _ AD.

In the related art, if the circuit where the first positive electrode 121 is located is closed through a switch to achieve the purpose of closing the power end to output to the load port 12, such a switching manner may require a large cost for electronic components; or, the circuit where the first cathode 122 is located is closed through a switch, so as to close the power end to output to the load port 12, and this switching manner causes that the processing module 13 cannot directly detect the voltage between the first anode 121 and the first cathode 122, so that corresponding logic control cannot be implemented.

It can be understood that, in the present embodiment, the switch module 14 is electrically connected to the first negative electrode 122 for controlling a loop of the first negative electrode 122, and the voltage detection module 11 is configured to detect a voltage value between the first positive electrode 121 and the first negative electrode 122. The processing module 13 may control a loop where the first cathode 122 is located according to a voltage between the first electrode and the second electrode, so as to implement automatic logic control.

In a possible implementation manner, referring to fig. 1 again, the voltage detection circuit 1 further includes a power supply terminal 15, the switch module 14 is further configured to be electrically connected to the second negative electrode 152 of the power supply terminal 15, and the first positive electrode 121 is electrically connected to the second positive electrode 151 of the power supply terminal 15, wherein when the switch module 14 is turned on, the first negative electrode 122 can be electrically connected to the second negative electrode 152 through the switch module 14, so that the power supply terminal 15 can supply power to the output of the load port 12.

Specifically, the switch module 14 is electrically connected to the first negative electrode 122 and the second negative electrode 152, so that on-off control between the first negative electrode 122 and the second negative electrode 152 is realized. When the switch module 14 is turned off, the first negative electrode 122 and the second negative electrode 152 are not conducted, so that the power source terminal 15 cannot supply power to the load port 12, and the effect of cutting off the power source terminal 15 from supplying power to the load port 12 is achieved; when the processing module 13 controls the switch module 14 to turn on, the first negative electrode 122 and the second negative electrode 152 are conducted, so that the power end 15 supplies power to the load port 12.

In a possible implementation manner, please refer to fig. 2, and fig. 2 is a schematic diagram of a voltage detection module framework according to an implementation manner of the present application. The isolated sensing unit 111 comprises a signal transmitting unit 1111 and a signal receiving unit 1112, the signal transmitting unit 1111 is electrically connected with the first anode 121 and the first cathode 122, the signal receiving unit 1112 is electrically connected with the processing module 13; wherein the signal transmitting unit 1111 is configured to generate a signal capable of being received by the signal receiving unit 1112 through non-electrical coupling based on the voltages of the first positive electrode 121 and the first negative electrode 122, and the signal receiving unit 1112 is configured to send the detection signal to the processing module 13 based on the signal received from the signal transmitting unit 1111.

In particular, since the signal transmitting unit 1111 can generate a signal that can be received by the signal receiving unit 1112 in a non-electrical coupling manner based on the voltages of the first positive pole 121 and the first negative pole 122, the processing module 13 can still detect the voltage value between the first positive pole 121 and the first negative pole 122 through the voltage detecting module 11 when the switch module 14 is turned off.

For example, the non-electrical coupling manner may include optical coupling, acoustic coupling, electromagnetic induction coupling, etc., or other coupling manners that do not require the signal transmitting unit 1111 and the signal receiving unit 1112 to be electrically connected in common ground, which is within the protection scope of the embodiments of the present application.

In a possible implementation manner, please refer to fig. 3, and fig. 3 is a schematic circuit diagram of a voltage detection module according to an embodiment of the present disclosure. The negative electrode of the signal receiving unit 1112 and the ground terminal of the processing module 13 are both electrically connected to one end of the switch module 14, and the negative electrode of the signal transmitting unit 1111 and the first negative electrode 122 are electrically connected to the other end of the switch module 14.

In a possible embodiment, the negative pole of the signal receiving unit 1112, the ground terminal of the processing module 13, and the second negative pole 152 are all electrically connected to one end of the switch module 14, and at this time, the second negative pole 152 provides a ground terminal for the signal receiving unit 1112 and the processing module 13; the negative electrode of the signal transmitting unit 1111 and the first negative electrode 122 are electrically connected to the other end of the switch module 14.

In this embodiment, please refer to fig. 3 again. The voltage detection module 11 includes a light emitting unit 112 and a light sensing unit 113, the light emitting unit 112 is electrically connected to the first positive electrode 121 and the first negative electrode 122, respectively, and the light sensing unit 113 is electrically connected to the processing module 13; wherein the light emitting unit 112 is configured to transmit an optical signal based on a voltage between the first positive electrode 121 and the first negative electrode 122; the light sensing unit 113 is configured to receive the light signal and generate the detection signal CAR _ AD based on the light signal.

Specifically, the light emitting unit 112 serves as the signal emitting unit 1111, and the light sensing unit serves as the signal receiving unit 1112. When the forward current or voltage is applied to the two ends of the light emitting unit 112, the light emitting unit 112 normally works to emit light, and it can be understood that the light intensity of the light emitted from the light emitting unit 112 is positively correlated to the magnitude of the forward current or voltage applied to the two ends of the light emitting unit 112, that is, the greater the forward current or voltage is applied to the two ends of the light emitting unit 112, the greater the light intensity of the light emitted from the light emitting unit 112 is.

When the photosensitive unit 113 receives light, the internal resistance of the photosensitive unit 113 decreases, and the degree of the decrease of the internal resistance is in positive correlation with the light intensity of the received light, that is, the larger the light intensity of the received light by the photosensitive unit 113 is, the smaller the internal resistance of the photosensitive unit 113 is.

In the present embodiment, as shown in fig. 2, the voltage detection module 11 further includes a voltage dividing resistor, and the light sensing unit 113 and the voltage dividing resistor are grounded in series. The smaller the internal resistance of the photosensitive cell 113 is, the larger the voltage value of the end of the photosensitive cell 113 electrically connected to the voltage dividing resistor is, so that the larger the voltage value of the detection signal CAR _ AD generated at the end of the photosensitive cell 113 is, that is, the voltage value of the detection signal CAR _ AD is inversely related to the internal resistance of the photosensitive cell 113.

It can be understood that, in the present embodiment, even when the first negative electrode 122 and the second negative electrode 152 are not turned on, that is, the switch module 14 is turned off, the voltage value between the first positive electrode 121 and the first negative electrode 122 can be coupled to the processing module 13 through the voltage detection module 11 by the light emitting unit 112 and the light receiving unit 113. In other possible implementations, the circuit of the voltage detection module 11 is not limited in the embodiments of the present application.

In one possible embodiment, the light emitting unit 112 may include a light emitting diode, and the light sensing unit 113 may include a photodiode.

In a possible implementation manner, please refer to fig. 1 again, the voltage detection circuit 1 further includes a driving module 16, the driving module 16 is electrically connected to the processing module 13 and the switch module 14, respectively, and the processing module 13 is further configured to send a control signal Mos _ EN to the driving module 16 to drive the switch module 14 to be turned on.

It should be noted that, in the circuit, the switch module 14 may adopt a transistor or a relay as one of main electronic components, in order to implement automatic logic control, the voltage detection circuit 1 further includes the driving module 16, and when the processing module 13 further sends a control signal Mos _ EN to the driving module 16, the driving module 16 may be configured to drive the switch module 14 to be turned on.

In one possible embodiment, the switching module 14 includes one or more field effect transistors (MOSFETs, MOS).

In one possible embodiment, the switch module 14 includes one or more NMOS transistors. In a possible implementation manner, please refer to fig. 4, and fig. 4 is a circuit schematic diagram of a switch module and a driving module according to an embodiment of the present disclosure. The switch module 14 includes a plurality of NMOS transistors.

It should be noted that in the circuit diagrams provided in the present application, nodes represented by the same reference numerals are electrically connected together, for example, GND, BAT +, and the like. In each drawing, CAR + is the first positive electrode 121, CAR-is the first negative electrode 122, BAT + is the second positive electrode 151, and GND is the second negative electrode 152, which will not be described in detail below.

Specifically, since the current at a moment when the vehicle is powered on is large, in this embodiment, the switch module 14 includes a plurality of NMOS transistors connected in parallel, so that the power-on current is dispersed in the plurality of NMOS transistors connected in parallel, thereby preventing the electronic components in the switch module 14 from being damaged by the excessive power-on current.

In the present embodiment, the switch module 14 employs an NMOS transistor, which is different from a PMOS transistor in that the NMOS transistor has a small on-resistance and is easy to manufacture. It can be understood that the switch module 14 employs NMOS transistors, which can further reduce the material cost of the voltage detection circuit 1.

In a possible implementation, in the case that the processing module 13 detects that the voltage value between the first positive pole 121 and the first negative pole 122 is greater than 0V, the processing module 13 outputs a control signal Mos _ EN to turn on the switching module 14 through the control signal Mos _ EN.

In this way, when the processing module 13 can detect that the voltage value between the first positive electrode 121 and the first negative electrode 122 of the load port 12 is greater than 0V, that is, when the load port 12 is connected to a load device (such as a vehicle battery), two ends of the load device provide voltage to the first positive electrode 121 and the first negative electrode 122 to drive the light emitting unit 112 to emit light, so that the light sensing unit 113 sends a corresponding detection signal CAR _ AD to the processing module 13. At this time, the processing module 13 may control the switch module 14 to be turned on, so that the power source terminal 15 outputs power to the load port 12, thereby supplying power to the load device connected to the load port 12.

In a possible implementation, in the case that the processing module 13 detects that the voltage value between the first positive electrode 121 and the first negative electrode 122 is greater than or equal to a preset voltage threshold, the processing module 13 outputs a control signal Mos _ EN to turn on the switching module 14 through the control signal Mos _ EN.

In this way, when the processing module 13 detects that the voltage value between the first positive electrode 121 and the first negative electrode 122 is greater than or equal to the preset voltage threshold, the processing module 13 controls the switch module 14 to turn on, so that the power source terminal 15 outputs power to the load port 12, thereby supplying power to the load port 12. The preset voltage threshold may be set based on an operating voltage of a load device to which the load port 12 is connected, for example, the preset voltage threshold may be 7V, 8V, 9V, 9.5V, or 10V. When the load equipment is a vehicle storage battery, the load equipment is allowed to output power to the load equipment connected with the load port 12 by the power supply end 15 when reaching a preset voltage threshold value, so that the vehicle can be ensured to normally work by utilizing the storage battery of the vehicle after being started.

It is understood that, in other possible embodiments, the preset voltage threshold may vary according to actual conditions, and the variation of the preset voltage threshold may be static or dynamic. The logic of the processing module 13 for controlling the driving module 16 may also be different, and the present application is not limited thereto.

In a possible implementation, in the case that the processing module 13 detects that the voltage value between the first positive electrode 121 and the first negative electrode 122 decreases, or the decrease rate reaches a preset decrease rate, the processing module 13 outputs a control signal Mos _ EN to enable the switching module 14 through the control signal Mos _ EN.

In this way, when the voltage value between the first positive electrode 121 and the first negative electrode 122 decreases, or the decrease rate reaches a preset decrease rate, indicating that the vehicle has a power failure, the vehicle may be performing an ignition operation, and at this time, the processing module 13 controls the switch module 14 to turn on, so that the power supply terminal 15 supplies power to the load port 12, thereby supplying power to the connected vehicle and supplying power to start the vehicle. In this way, the processing module 13 allows the vehicle to be supplied with electric energy when detecting that the vehicle is on fire, so that the intellectualization of power supply is realized, and the electricity is saved.

In a possible implementation manner, when the voltage value between the first positive electrode 121 and the first negative electrode 122 is smaller than the voltage value of the power source terminal, the processing module 13 sends the control signal to the driving module 16 to drive the switching module 14 to turn on. In this way, the load device connected to the first positive electrode 121 and the first negative electrode 122 can be prevented from flowing backward to the power source of the power source terminal 15.

In a possible implementation manner, please refer to fig. 1 again, the voltage detection circuit 1 further includes a power supply module 17, the power supply module 17 is electrically connected to the processing module 13 and the second positive electrode 151, respectively, and the power supply module 17 is configured to supply power to the processing module 13.

For example, the current or voltage supplied by the power supply terminal 15 is generally large, and the processing module 13 and the like cannot be directly supplied with power, so that the power supply module 17 is required to perform voltage regulation processing on the current or voltage supplied by the power supply terminal 15. In this embodiment, the power supply module 17 is electrically connected to the second positive electrode 151, and the voltage value provided by the second positive electrode 151 is reduced to 5V by the power supply module 17 and transmitted to the processing module 13, so that the processing module 13 operates normally. As another example, the current or voltage provided by the power supply terminal 15 may be unstable, and the power supply module may perform a voltage stabilization process on the current or voltage provided by the power supply terminal 15 to provide the stable current or voltage to the processing module 13. Furthermore, the power supply module 17 may be a combination of the two examples.

It is understood that, in other possible embodiments, the arrangement of the power supply module 17 is not limited in this application as long as the normal operation of the processing module 13 is not affected, for example, a power supply is additionally provided to supply power to the processing module 13.

In a possible implementation manner, please refer to fig. 5, and fig. 5 is a schematic diagram of a voltage detection circuit according to an embodiment of the present disclosure. It should be noted that the electronic components and the electrical connection mode shown in fig. 5 are only one embodiment provided in the present application, and do not represent that the present application limits the circuit configuration of the voltage detection circuit 1.

The isolation sensing unit 111 is a U3, the current limiting resistor is a R15, and the anti-reverse diode is a D4. When CAR + and CAR-are connected to the load device in the forward direction, the light-emitting unit 112 in U3 is turned on, and when the voltage between CAR + and CAR-is higher, the light intensity of the light-emitting unit 112 in the U3 is higher, the light-receiving unit 113 is better in conduction, and the internal resistance is lower. After the voltage division of the light sensing units 113 and R14, the detection signal CAR _ AD voltage signal is output, and the detection signal CAR _ AD voltage is proportional to the CAR + voltage value. The processing module 13 can determine the voltage value of the load device by detecting the voltage of the detection signal CAR _ AD. The processing module 13 outputs different control logics according to voltage values of different load devices, and is configured to output the control signal MOS _ EN signal, so that the switch module 14 at the negative end of the loop is turned on or turned off.

In one possible implementation, the processing module 13 may include one or more of a driver board, a microprocessor, other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component. The driving board may include a Central Processing Unit (CPU), other general purpose processors, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, and the like.

Fig. 6 is a schematic view of a vehicle emergency starting power supply device according to an embodiment of the present application. The vehicle emergency starting power supply 2 comprises the voltage detection circuit 1 and the power supply 21 as described above, and the power supply 21 provides voltage or current for the power supply terminal 15. Specifically, the voltage detection circuit 1 refers to the above description, and is not described herein again.

Fig. 6 and 7 are combined, and fig. 7 is a schematic view of a battery clamp 3 according to an embodiment of the present disclosure. The battery clamp 3 includes a housing 31 and the voltage detection circuit 1 as described above, and the voltage detection circuit 1 is at least partially disposed in the housing 31.

Specifically, the battery clamp 3 further includes two clamps 32, one of the two clamps 32 is an anode clamp for clamping an anode of a load device (such as an automobile battery), and the other is a cathode clamp for clamping a cathode of the load device. It is understood that the battery clamp 3 may have other structures in other possible embodiments, and the present application is not limited thereto.

The principle and the embodiment of the present application are explained herein by applying specific examples, and the above description of the embodiment is only used to help understand the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A voltage detection circuit is characterized by comprising a voltage detection module, a processing module, a switch module and a load port, wherein the load port comprises a first positive pole and a first negative pole, and the voltage detection module comprises an isolation sensing unit; wherein,

2. The voltage detection circuit of claim 1, wherein the voltage detection circuit further comprises a power supply terminal, the switch module is further configured to be electrically connected to a second negative terminal of the power supply terminal, the first positive terminal is electrically connected to a second positive terminal of the power supply terminal, wherein,

3. The voltage detection circuit of claim 1, wherein the isolation sensing unit comprises a signal transmitting unit and a signal receiving unit, the signal transmitting unit is electrically connected with the first positive pole and the first negative pole, and the signal receiving unit is electrically connected with the processing module; wherein,

the signal transmitting unit is used for generating a signal which can be received by the signal receiving unit in a non-electric coupling mode based on the voltages of the first positive pole and the first negative pole;

the signal receiving unit is used for sending the detection signal to the processing module based on the signal received from the signal transmitting unit.

4. The voltage detection circuit of claim 3, wherein a negative electrode of the signal receiving unit and a ground terminal of the processing module are electrically connected to one end of the switch module, and a negative electrode of the signal transmitting unit and the first negative electrode are electrically connected to the other end of the switch module.

5. The voltage detection circuit of claim 1, wherein the voltage detection module comprises a light emitting unit and a light sensing unit, the light emitting unit is electrically connected to the first positive electrode and the first negative electrode, respectively, and the light sensing unit is electrically connected to the processing module; wherein,

6. The voltage detection circuit of claim 1, wherein the switch module comprises a plurality of NMOS transistors.

7. The voltage detection circuit of claim 1, wherein the processing module outputs a control signal to turn on the switch module by the control signal when the processing module detects that the voltage value between the first positive pole and the first negative pole is greater than 0V.

8. The voltage detection circuit of claim 1, wherein the processing module outputs a control signal to turn on the switch module by the control signal when the processing module detects that the voltage value between the first positive electrode and the first negative electrode is greater than or equal to a preset voltage threshold value.

9. The voltage detection circuit of claim 1, wherein in a case where the processing module detects that the voltage value between the first positive electrode and the first negative electrode decreases, or the rate of decrease reaches a preset rate of decrease, the processing module outputs a control signal to turn on the switching module by the control signal.

10. The voltage detection circuit of claim 1, further comprising a driving module electrically connected to the processing module and the switch module, respectively, wherein the processing module is further configured to send a control signal to the driving module to drive the switch module to turn on.

11. The voltage detection circuit of claim 2, further comprising a power module electrically connected to the processing module and the second positive electrode, respectively, the power module configured to supply power to the processing module.

12. A vehicle emergency starting power supply comprising a voltage detection circuit according to any one of claims 1 to 11 and a power supply, the voltage detection circuit comprising a power supply terminal, the power supply supplying a voltage or a current to the power supply terminal.

13. A battery clamp, characterized in that it comprises a housing and a voltage detection circuit according to any one of claims 1 to 11, which is at least partially arranged in the housing.