Voltage sampling circuit and vehicle

Abstract

The utility model provides a voltage sampling circuit and a vehicle, the circuit is applied to the vehicle field, the first and second ends of a switch assembly are respectively electrically connected with the first and second contacts of a contactor to be detected, and the third and fourth ends are respectively electrically connected with one end of a first and second acquisition circuits; the first acquisition circuit and the second acquisition circuit are used for adjusting acquisition channel states between the to-be-detected contactor and the first and second acquisition circuits according to a preset time sequence; the first acquisition circuit and the second acquisition circuit respectively acquire voltage values of the first contact and the second contact when the acquisition channel state is a connection state; the first and second input ends of the processing circuit are electrically connected with the other ends of the first and second acquisition circuits respectively, the third input end is connected with a power supply, the fourth input end is grounded, and the output end is used for outputting the voltage difference of the contactor to be detected according to the voltage values of the first and second contacts. The circuit performs service life detection based on the voltage values of the contacts at the two ends of the contactor to be detected, so that early warning is performed for the failure problem, and safety accidents are avoided.

Description

Technical Field

[0001] The utility model relates to the field of vehicles, and more specifically, to a voltage sampling circuit and a vehicle in the field of vehicles. Background Art

[0002] The battery pack main positive contactor is a switching device used to control the connection between the battery pack and the main positive circuit of the electric vehicle. It controls the high-voltage power system of the electric vehicle. When it works normally, it ensures the safety and reliability of the battery pack during the normal starting, driving and parking of the electric vehicle. It is one of the very important components in electric vehicles.

[0003] However, in order to meet user needs, electric vehicles need to be charged and used frequently, which will cause the contact surface of the battery pack's main positive contactor to be subject to certain wear and corrosion, thereby causing the battery pack to fail to shut down or start, posing a safety hazard. Therefore, life detection of the battery pack's main positive contactor is very necessary. Utility Model Content

[0004] The utility model provides a voltage sampling circuit and a vehicle. The sampling circuit can perform life detection on a contactor to be detected based on the voltage values ​​of contacts at both ends of the contactor to be detected, thereby providing early warning for failure problems of the contactor to be detected and effectively avoiding the occurrence of safety accidents.

[0005] In a first aspect, a voltage sampling circuit is provided, comprising: a switch component, a first acquisition circuit, a second acquisition circuit and a processing circuit, wherein a first end of the switch component is electrically connected to a first contact of the contactor to be detected, a second end of the switch component is electrically connected to a second contact of the contactor to be detected, a third end of the switch component is electrically connected to one end of the first acquisition circuit, and a fourth end of the switch component is electrically connected to one end of the second acquisition circuit, and the switch component is used to adjust a first acquisition channel state between the contactor to be detected and the first acquisition circuit and a second acquisition channel state between the contactor to be detected and the second acquisition circuit according to a preset timing sequence; The first acquisition circuit is used to acquire the voltage value of the first contact when the first acquisition channel state is a connected state; the second acquisition circuit is used to acquire the voltage value of the second contact when the second acquisition channel state is the connected state; the first input end of the processing circuit is electrically connected to the other end of the first acquisition circuit, the second input end of the processing circuit is electrically connected to the other end of the second acquisition circuit, the third input end of the processing circuit is electrically connected to a power access node, the fourth input end of the processing circuit is electrically connected to a ground node, and the output end of the processing circuit is used to output the voltage difference of the contactor to be detected according to the voltage value of the first contact and the voltage value of the second contact.

[0006] Through the above technical solution, the life of the contactor to be detected can be detected based on the voltage values ​​of the contacts at both ends of the contactor to be detected, so as to give an early warning when a failure problem is detected in the contactor to be detected, thereby effectively avoiding the occurrence of safety accidents.

[0007] In combination with the first aspect, in some possible implementations, the switch component includes: a first switch, the first switch includes a first coil, a third contact and a fourth contact, one end of the first coil is electrically connected to the ground node, the other end of the first coil is electrically connected to the first signal input terminal, the third contact is electrically connected to the first contact, and the fourth contact is electrically connected to the first acquisition circuit; and / or, a second switch, the second switch includes a second coil, a fifth contact and a sixth contact, one end of the second coil is electrically connected to the ground node, the other end of the second coil is electrically connected to the second signal input terminal, the fifth contact is electrically connected to the second contact, and the sixth contact is electrically connected to the second acquisition circuit.

[0008] Through the above technical solution, the two contact points between the voltage sampling circuit and the contactor to be detected are disconnected by the first switch and the second switch, so as to avoid damage to the amplifier caused by the connection between the voltage sampling circuit and the contactor to be detected after the contactor to be detected is disconnected.

[0009] In combination with the first aspect and the above-mentioned implementation manner, in some possible implementation manners, the first acquisition circuit includes: a first resistor and a second resistor connected in series, wherein one end of the first resistor is electrically connected to the third end of the switch component, the other end of the first resistor is electrically connected to one end of the second resistor, and the other end of the second resistor is electrically connected to the first input end of the processing circuit; the second acquisition circuit includes: a third resistor and a fourth resistor connected in series, wherein one end of the third resistor is electrically connected to the fourth end of the switch component, the other end of the third resistor is electrically connected to one end of the fourth resistor, and the other end of the fourth resistor is electrically connected to the second input end of the processing circuit.

[0010] Through the above technical solution, the first acquisition circuit composed of the first resistor and the second resistor acquires the voltage value of the first contact of the contactor to be detected, and the second acquisition circuit composed of the third resistor and the fourth resistor acquires the voltage value of the second contact of the contactor to be detected, so that when it is detected that the voltage value of the first contact of the contactor to be detected is too high or the voltage value of the second contact is too high, an early warning can be given to avoid malfunction of the contactor to be detected.

[0011] In combination with the first aspect and the above-mentioned implementation manner, in some possible implementation manners, the processing circuit includes: a fifth resistor, one end of the fifth resistor is electrically connected to the connection node between the second resistor and the first input terminal, and the other end of the fifth resistor is electrically connected to the output terminal of the processing circuit; a sixth resistor, one end of the sixth resistor is electrically connected to the connection node between the fourth resistor and the second input terminal, and the other end of the sixth resistor is electrically connected to the ground node; a bidirectional breakdown diode, one end of the bidirectional breakdown diode is electrically connected to the connection node between the second resistor and the first input terminal, and the other end of the bidirectional breakdown diode is electrically connected to the connection node between the fourth resistor and the second input terminal; an amplifier, the in-phase input terminal of the amplifier is the first input terminal, the inverting input terminal of the amplifier is the second input terminal, the power input terminal of the amplifier is the third input terminal, the ground terminal of the amplifier is the fourth input terminal, and the output terminal of the amplifier is the output terminal of the processing circuit.

[0012] Through the above technical solution, after the voltage signals of the contacts at both ends of the contactor to be detected are collected, the voltage signals are amplified to eliminate signal interference, thereby improving the life detection accuracy of the contactor to be detected.

[0013] In combination with the first aspect and the above implementations, in some possible implementations, the amplifying element is an amplifier.

[0014] Through the above technical solution, the collected voltage signal of the contactor to be detected is amplified by the amplifier to ensure that the voltage signal can be correctly processed in the subsequent circuit or device.

[0015] In combination with the first aspect and the above implementations, in some possible implementations, both the first switch and the second switch are relays.

[0016] Through the above technical solution, a relay is added to prevent the amplifier from being subjected to a very large voltage after the contactor to be detected is disconnected, thereby preventing the amplifier from being damaged.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the above-mentioned voltage sampling circuit also includes: a control component, the control component is connected to the output end of the processing circuit, the control component obtains the current remaining life of the contactor to be detected according to the voltage difference of the contactor to be detected by looking up the table; a display component, the display component is connected to the control component, and the display component is used to display the current remaining life.

[0018] Through the above technical solution, the control component obtains the current remaining life of the contactor to be detected by looking up the table according to the voltage difference, and displays the remaining life, which can effectively warn before the contactor to be detected fails to prevent safety accidents.

[0019] In a second aspect, a vehicle is provided, comprising: the voltage sampling circuit as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the connection relationship of a voltage sampling circuit provided by an embodiment of the utility model;

[0021] Figure 2 The present invention is a contactor life detection circuit diagram according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings to clearly and thoroughly describe the technical solution in the utility model. In the description of the embodiment of the utility model, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiment of the utility model, "multiple" means two or more than two.

[0023] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0024] The main positive contactor of the battery pack serves as a connecting switch device for controlling the battery pack and the main positive circuit of the whole vehicle. Its main function is to control the working state of the battery pack to ensure the safety and reliability of the battery pack when the vehicle is started, running and parked. During the frequent charging and use of electric vehicles by users, the contact surface of the main positive contactor of the battery pack will be subject to certain wear and corrosion. However, there is a lack of life detection for the main positive contactor of the battery pack in the related technology, which makes it impossible to quickly and effectively detect the failure problem of the main positive contactor of the battery pack and give early warning, increasing serious safety hazards such as fire. The utility model designs a voltage sampling circuit, which can perform life detection on the main positive contactor of the battery pack with fewer components. The detection result has good real-time performance and high reliability, so that the failure problem of the main positive contactor of the battery pack can be warned in advance to prevent safety accidents.

[0025] Figure 1It is a schematic diagram of the connection relationship of a voltage sampling circuit provided by an embodiment of the utility model.

[0026] For example, Figure 1 As shown, the voltage sampling circuit 10 includes: a switch component 100 , a first acquisition circuit 200 , a second acquisition circuit 300 and a processing circuit 400 .

[0027] The first end of the switch component 100 is electrically connected to the first contact KEY1(+) of the contactor KEY1 to be detected, the second end of the switch component 100 is electrically connected to the second contact KEY1(-) of the contactor KEY1 to be detected, the third end of the switch component 100 is electrically connected to one end of the first acquisition circuit 200, and the fourth end of the switch component 100 is electrically connected to one end of the second acquisition circuit 300. The switch component 100 is used to adjust the first acquisition channel state between the contactor KEY1 to be detected and the first acquisition circuit 200 and the second acquisition channel state between the contactor KEY1 to be detected and the second acquisition circuit 300 according to a preset timing sequence; the first acquisition circuit 2 ... The voltage value of the first contact KEY1 (+) is collected when the second collection channel state is the connection state; the second collection circuit 300 is used to collect the voltage value of the second contact KEY1 (-) when the second collection channel state is the connection state; the first input end of the processing circuit 400 is electrically connected to the other end of the first collection circuit 200, the second input end of the processing circuit 400 is electrically connected to the other end of the second collection circuit 300, the third input end of the processing circuit 400 is electrically connected to the power access node, the fourth input end of the processing circuit 400 is electrically connected to the ground node, and the output end of the processing circuit 400 is used to output the voltage difference of the contactor KEY1 to be detected according to the voltage value of the first contact KEY1 (+) and the voltage value of the second contact KEY1 (-).

[0028] The preset timing may be set by those skilled in the art according to the actual acquisition situation of the voltage sampling circuit, or may be obtained through a limited number of computer simulations, which is not specifically limited here.

[0029] Specifically, the main positive contactor of the battery pack serves as a connecting switch device that controls the battery pack and the main positive circuit of the vehicle. It is the hub that enables the vehicle to run normally. Therefore, in order to ensure the driving safety of users, the utility model mainly performs life detection on the contactor to be detected KEY1 based on collecting the voltage values ​​of the contacts at both ends of the main positive contactor of the battery pack, that is, the contactor to be detected KEY1, so as to provide early warning of failure problems of the contactor to be detected KEY1 according to the voltage values ​​of the contacts at both ends of the contactor to be detected KEY1.

[0030] Further, in some embodiments, the first acquisition circuit 200 includes: a first resistor and a second resistor connected in series, wherein one end of the first resistor is electrically connected to the third end of the switch component 100, the other end of the first resistor is electrically connected to one end of the second resistor, and the other end of the second resistor is electrically connected to the first input end of the processing circuit 400; the second acquisition circuit 300 includes: a third resistor and a fourth resistor connected in series, wherein one end of the third resistor is electrically connected to the fourth end of the switch component 100, the other end of the third resistor is electrically connected to one end of the fourth resistor, and the other end of the fourth resistor is electrically connected to the second input end of the processing circuit 400.

[0031] Further, in some embodiments, the processing circuit 400 includes: a fifth resistor, one end of the fifth resistor is electrically connected to the connection node between the second resistor and the first input terminal, and the other end of the fifth resistor is electrically connected to the output terminal of the processing circuit 400; a sixth resistor, one end of the sixth resistor is electrically connected to the connection node between the fourth resistor and the second input terminal, and the other end of the sixth resistor is electrically connected to the ground node; a bidirectional breakdown diode, one end of the bidirectional breakdown diode is electrically connected to the connection node between the second resistor and the first input terminal, and the other end of the bidirectional breakdown diode is electrically connected to the connection node between the fourth resistor and the second input terminal; an amplifier, the in-phase input terminal of the amplifier is the first input terminal, the inverting input terminal of the amplifier is the second input terminal, the power input terminal of the amplifier is the third input terminal, the ground terminal of the amplifier is the fourth input terminal, and the output terminal of the amplifier is the output terminal of the processing circuit 400.

[0032] Specifically, if Figure 1 As shown, the voltage sampling circuit 10 mainly includes a switch component 100, a first acquisition circuit 200, a second acquisition circuit 300 and a processing circuit 400, wherein the first acquisition circuit 200 mainly includes a first resistor R1 and a second resistor R2 connected in series, one end of the first resistor R1 is electrically connected to the third end of the switch component 100, the other end of the first resistor R1 is electrically connected to one end of the second resistor R2, the other end of the second resistor R2 is electrically connected to the first input terminal U1(+) of the processing circuit 400, and the first end of the switch component 100 is electrically connected to the first contact KEY1(+) of the contactor KEY1 to be detected, so that the voltage value of the first contact KEY1(+) of the contactor KEY1 to be detected is collected according to the designed first acquisition circuit 200.

[0033] The second acquisition circuit 300 mainly includes a third resistor R3 and a fourth resistor R4 connected in series, wherein one end of the third resistor R3 is electrically connected to the fourth end of the switch component 100, the other end of the third resistor R3 is electrically connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is electrically connected to the second input terminal U1(-) of the processing circuit 400, and the second end of the switch component 100 is electrically connected to the first contact KEY1(-) of the contactor KEY1 to be detected, so that the designed second acquisition circuit 300 collects the voltage value of the second contact KEY1(-) of the contactor KEY1 to be detected.

[0034] The processing circuit 400 mainly includes a fifth resistor R6, a sixth resistor R5, a bidirectional breakdown diode D1 and an amplifier U1. It should be noted that the sizes of the first resistor to the sixth resistor of the utility model are determined by the input voltage. At the same time, in order to calculate the voltage difference between the contact points at both ends of the contactor KEY1 to be detected and make the voltage difference tend to be stable, the utility model adopts the amplifier U1 to perform corresponding calculations. Preferably, the amplifier U1 of the utility model can select an amplifier.

[0035] Among them, one end of the fifth resistor R6 is electrically connected to the connection node between the second resistor R2 and the in-phase input terminal of the amplifier U1, that is, the first input terminal U1(+), and the other end of the fifth resistor R6 is electrically connected to the output terminal ADC_IN1 of the processing circuit 400; one end of the sixth resistor R5 is electrically connected to the connection node between the fourth resistor R4 and the inverting input terminal of the amplifier U1, that is, the second input terminal U1(-), and the other end of the sixth resistor R5 is electrically connected to the ground node; one end of the bidirectional breakdown diode D1 is electrically connected to the connection node between the second resistor R2 and the first input terminal U1(+), and the other end of the bidirectional breakdown diode D1 is electrically connected to the connection node between the fourth resistor R4 and the second input terminal U1(-); the power input terminal of the amplifier U1 is the third input terminal, the ground terminal of the amplifier U1 is the fourth input terminal, and the output terminal of the amplifier U1 is the output terminal ADC_IN1 of the processing circuit 400.

[0036] It can be understood that, in some cases, the first input terminal U1(+) and the second input terminal U1(-) of the amplifier U1 will be connected to the power supply, and two voltage reference points will appear at this time, thereby ensuring that the total power supply voltage of the amplifier U1 is in the effective range, so that the amplifier U1 can operate normally. In the present utility model, in order to realize the functions of voltage follower amplification, integration, differentiation, etc., the first input terminal U1(+) can be connected to the power supply, for example, the voltage value of the third input terminal can be 4.5V, and the fourth input terminal U1(-) is grounded. At the same time, after the voltage values ​​of the contact points at both ends of the contactor KEY1 to be detected are collected by the first acquisition circuit 200 and the second acquisition circuit 300, the amplifier U1 obtains the voltage difference of the contactor KEY1 to be detected according to the voltage values ​​of the contact points at both ends, and amplifies the voltage difference. In order to meet the detection effect, the present utility model can determine the voltage difference amplification factor of the contactor KEY1 to be detected according to R6 / (R1+R2), and at the same time satisfy R1+R2=R3+R4, R6=R5, which is simple to calculate and can thus achieve the characteristics of impedance matching.

[0037] It should be noted that the voltage difference amplification factor used in the present invention can be obtained by those skilled in the art based on historical data from multiple tests, or by a limited number of computer simulations. Preferably, the voltage difference amplification factor of the present invention is set to R6 / (R1+R2), and its specific calculation method can adopt the amplification factor calculation method of the amplifier U1 in the relevant technology, which will not be described in detail here.

[0038] Further, in some embodiments, the switch assembly 100 includes: a first switch, the first switch includes a first coil, a third contact and a fourth contact, one end of the first coil is electrically connected to the ground node, the other end of the first coil is electrically connected to the first signal input terminal, the third contact is electrically connected to the first contact, and the fourth contact is electrically connected to the first acquisition circuit; and / or, a second switch, the second switch includes a second coil, a fifth contact and a sixth contact, one end of the second coil is electrically connected to the ground node, the other end of the second coil is electrically connected to the second signal input terminal, the fifth contact is electrically connected to the second contact, and the sixth contact is electrically connected to the second acquisition circuit.

[0039] Specifically, Figure 2As shown, in order to prevent the first input terminal U1(+) and the second input terminal U1(-) of the amplifier U1 from being subjected to a very large common mode voltage after the contactor KEY1 to be detected is disconnected, thereby causing damage to the amplifier U1, the embodiment of the utility model can add a switch component 100 (such as a relay) to the input end of the voltage sampling circuit 10, so that the first acquisition channel state between the contactor KEY1 to be detected and the first acquisition circuit 200 and the second acquisition channel state between the contactor KEY1 to be detected and the second acquisition circuit 300 can be adjusted according to a preset timing, which mainly includes a first switch KEY2 and / or a second switch KEY3, wherein the first switch KEY2 includes a first coil, a third contact KEY2(-) and a fourth contact KEY2(+), one end of the first coil is electrically connected to the ground node, and the other end thereof is electrically connected to the first signal input end, the third contact KEY2(-) is electrically connected to the first contact KEY1(+), and the fourth contact KEY2(+) is electrically connected to the first acquisition circuit 200.

[0040] The second switch KEY3 includes a second coil, a fifth contact KEY3(+) and a sixth contact KEY3(-), one end of the second coil is electrically connected to the ground node, and the other end thereof is electrically connected to the second signal input terminal, the fifth contact KEY3(+) is electrically connected to the second contact KEY1(-), and the sixth contact KEY3(-) is electrically connected to the second acquisition circuit 300. Therefore, when the state of the first acquisition channel between the contactor KEY1 to be detected and the first acquisition circuit 200 is adjusted to be in a connected state based on the first switch KEY2 according to a preset timing, the first acquisition circuit 200 acquires the voltage value of the first contact KEY1(+), and / or when the state of the second acquisition channel between the contactor KEY1 to be detected and the second acquisition circuit 300 is adjusted to be in a connected state based on the second switch KEY3 according to a preset timing, the second acquisition circuit 300 acquires the voltage value of the second contact KEY1(-), thereby preventing the amplifier U1 from being damaged.

[0041] Specifically, a relay is an electrical component that realizes time control through a mechanical timing device. It is composed of a timing mechanism, a contact group and an electromagnet. Its principle is to perform corresponding work based on the attraction and release of the electromagnet. Among them, the timing mechanism controls the on and off of the circuit by setting a time interval and controlling the opening and closing of the contacts. In the utility model, the time interval can be set to 500ms. If the first contact KEY1(+) and the second contact KEY1(-) of the contactor KEY1 to be detected attract the relay, an instruction to attract the first switch KEY2 and the second switch KEY3 to attract the relay is received after 500ms; if the first contact KEY1(+) and the second contact KEY1(-) of the contactor KEY1 to be detected are controlled to be disconnected, 500ms before the first contact KEY1(+) and the second contact KEY1(-) of the contactor KEY1 to be detected are disconnected, the first switch KEY2 and the second switch KEY3 need to be controlled to be disconnected first, thereby avoiding that after the contactor KEY1 to be detected is disconnected, the voltage sampling circuit 10 is still connected to the contact ends of the contactor KEY1 to be detected, causing damage to the amplifier U1.

[0042] Furthermore, in some embodiments, the voltage sampling circuit 10 further includes: a control component, which is connected to the output end of the processing circuit 400, and the control component obtains the current remaining life of the contactor to be detected by looking up the table according to the voltage difference of the contactor to be detected; and a display component, which is connected to the control component and is used to display the current remaining life.

[0043] Among them, the control component of the utility model is an MCU (Micro Controller Unit), and the display component can be a vehicle-mounted display, an LED (Light Emitting Diode) lamp, and other related components with display functions, which are not specifically limited here.

[0044] Specifically, the utility model collects the voltage value of the first contact KEY1(+) of the contactor KEY1 to be detected by the first acquisition circuit 200 when the first acquisition channel state is the connected state, and collects the voltage value of the second contact KEY1(-) of the contactor KEY1 to be detected by the second acquisition circuit 300 when the second acquisition channel state is the connected state, and then generates a voltage difference between the first contact KEY1(+) and the second contact KEY1(-) through the amplifier U1, and after being amplified by the amplifier U1 according to the amplification factor, the voltage difference is output to the control component through the output terminal ADC_IN1 of the processing circuit 400, and the control component obtains the current remaining life of the contactor KEY1 to be detected by looking up the table according to the voltage difference, and displays the current remaining life of the contactor KEY1 to be detected to the user through the display component, so that the user can understand the current remaining life of the contactor KEY1 to be detected, so that an early warning can be given before the contactor KEY1 to be detected fails to prevent the occurrence of safety accidents.

[0045] It should be noted that the utility model has generated a mapping relationship table between the voltage difference between the two ends of the contactor KEY1 to be detected and the corresponding current remaining life based on historical test data. Therefore, after obtaining the voltage difference between the first contact KEY1 (+) and the second contact KEY1 (-) of the contactor KEY1 to be detected, the utility model can directly look up the table according to the voltage difference to obtain the corresponding current remaining life of the contactor KEY1 to be detected.

[0046] In summary, the voltage sampling circuit of the embodiment of the utility model includes a first and a second end of the switch assembly electrically connected to the first contact and the second contact of the contactor to be detected, respectively, and a third end and a fourth end electrically connected to one end of the first and second acquisition circuits, respectively, for adjusting the acquisition channel state between the contactor to be detected and the first and second acquisition circuits according to a preset timing; the first and second acquisition circuits respectively acquire the voltage values ​​of the first and second contacts when the acquisition channel state is a connection state; the first and second input ends of the processing circuit are electrically connected to the other ends of the first and second acquisition circuits, respectively, the third input end is connected to the power supply, the fourth input end is grounded, and the output end is used to output the voltage difference of the contactor to be detected according to the voltage values ​​of the first and second contacts. The circuit performs life detection based on the voltage values ​​of the contacts at both ends of the contactor to be detected, thereby providing an early warning for the failure problem of the contactor to be detected and avoiding safety accidents.

[0047] This embodiment also provides a vehicle, which includes the voltage sampling circuit of the above embodiment. Since the vehicle has the above voltage sampling circuit, it can perform life detection on the contactor to be detected based on the voltage values ​​of the contacts at both ends of the contactor to be detected, thereby providing early warning for the failure of the contactor to be detected, effectively avoiding the occurrence of safety accidents.

[0048] The above contents are only specific implementation methods of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A voltage sampling circuit, characterized in that: include: A switch component, a first acquisition circuit, a second acquisition circuit and a processing circuit, wherein: The first end of the switch component is electrically connected to the first contact of the contactor to be detected, the second end of the switch component is electrically connected to the second contact of the contactor to be detected, the third end of the switch component is electrically connected to one end of the first acquisition circuit, and the fourth end of the switch component is electrically connected to one end of the second acquisition circuit. The switch component is used to adjust the first acquisition channel state between the contactor to be detected and the first acquisition circuit and the second acquisition channel state between the contactor to be detected and the second acquisition circuit according to a preset timing sequence; The first acquisition circuit is used for acquiring the voltage value of the first contact when the first acquisition channel is in a connected state; The second acquisition circuit is used for acquiring the voltage value of the second contact when the state of the second acquisition channel is the connection state; The first input end of the processing circuit is electrically connected to the other end of the first acquisition circuit, the second input end of the processing circuit is electrically connected to the other end of the second acquisition circuit, the third input end of the processing circuit is electrically connected to a power access node, the fourth input end of the processing circuit is electrically connected to a ground node, and the output end of the processing circuit is used to output the voltage difference of the contactor to be detected according to the voltage value of the first contact and the voltage value of the second contact.

2. The voltage sampling circuit according to claim 1, characterized in that: The switch assembly comprises: a first switch, wherein the first switch comprises a first coil, a third contact and a fourth contact, wherein one end of the first coil is electrically connected to the ground node, the other end of the first coil is electrically connected to the first signal input end, the third contact is electrically connected to the first contact, and the fourth contact is electrically connected to the first acquisition circuit; And / or, a second switch, the second switch includes a second coil, a fifth contact and a sixth contact, one end of the second coil is electrically connected to the ground node, the other end of the second coil is electrically connected to the second signal input end, the fifth contact is electrically connected to the second contact, and the sixth contact is electrically connected to the second acquisition circuit.

3. The voltage sampling circuit according to claim 1, characterized in that: The first acquisition circuit includes: A first resistor and a second resistor are connected in series, wherein One end of the first resistor is electrically connected to the third end of the switch component, the other end of the first resistor is electrically connected to one end of the second resistor, and the other end of the second resistor is electrically connected to the first input end of the processing circuit; The second acquisition circuit includes: A third resistor and a fourth resistor connected in series, wherein, One end of the third resistor is electrically connected to the fourth end of the switch component, the other end of the third resistor is electrically connected to one end of the fourth resistor, and the other end of the fourth resistor is electrically connected to the second input end of the processing circuit.

4. The voltage sampling circuit according to claim 1, characterized in that: The processing circuit comprises: a fifth resistor, one end of the fifth resistor being electrically connected to a connection node between the second resistor and the first input terminal, and the other end of the fifth resistor being electrically connected to an output terminal of the processing circuit; a sixth resistor, one end of the sixth resistor being electrically connected to a connection node between the fourth resistor and the second input terminal, and the other end of the sixth resistor being electrically connected to the ground node; a bidirectional breakdown diode, one end of which is electrically connected to a connection node between the second resistor and the first input terminal, and the other end of which is electrically connected to a connection node between the fourth resistor and the second input terminal; The amplifier has a non-inverting input terminal as the first input terminal, an inverting input terminal as the second input terminal, a power input terminal as the third input terminal, a ground terminal as the fourth input terminal, and an output terminal as the output terminal of the processing circuit.

5. The voltage sampling circuit according to claim 4, characterized in that: The amplifying element is an amplifier.

6. The voltage sampling circuit according to claim 2, characterized in that: The first switch and the second switch are both relays.

7. The voltage sampling circuit according to claim 1, characterized in that: Also includes: A control component, the control component is connected to the output end of the processing circuit, and the control component obtains the current remaining life of the contactor to be detected by looking up a table according to the voltage difference of the contactor to be detected; A display component is connected to the control component, and the display component is used to display the current remaining life.

8. A vehicle, characterized in that: include: The voltage sampling circuit according to any one of claims 1 to 7.

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