Lithium battery voltage simulation regulator and multi-string lithium battery pack protection board test equipment

Abstract

The utility model discloses a lithium battery voltage simulation regulator, which is applied to a multi-string lithium battery pack protection board test device, and comprises an adjustable voltage-stabilized power supply which is connected with an external alternating-current power supply and rectifies and reduces the voltage of the external alternating-current power supply into a direct-current power supply for output; the voltage regulating circuit is connected with the adjustable voltage-stabilized power supply and is used for enabling the adjustable voltage-stabilized power supply to output first voltage, second voltage or third voltage so as to supply power to the voltmeter; the selection switch is connected with the voltage regulating circuit and is used for selectively outputting the first voltage, the second voltage or the third voltage; the step-down circuit is connected in series between the output end of the voltage regulating circuit and the detection voltage end; and the voltage reduction module is used for reducing the first voltage into the lithium battery pack undervoltage test voltage and then outputting the voltage from the detection voltage end, reducing the second voltage into the lithium battery pack working test voltage and then outputting the voltage from the detection voltage end, and reducing the third voltage into the lithium battery overvoltage test voltage and then outputting the voltage from the detection voltage end. According to the scheme, the testing speed is high, the efficiency is higher, and larger testing current can be supported.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium battery protection boards, in particular to a lithium battery voltage simulation regulator and a multi-string lithium battery pack protection board testing device. Background Art

[0002] Lithium battery protection board is mainly an integrated circuit board that protects rechargeable (generally refers to lithium batteries). The reason why lithium batteries (rechargeable) need protection is determined by their own characteristics. Since the material of the lithium battery itself determines that it cannot be overcharged, over-discharged, over-current, short-circuited, and charged and discharged at ultra-high temperatures, lithium batteries / lithium battery packs always come with protection boards to ensure the safety of lithium batteries / lithium battery packs. Since the performance of the protection board is related to the safe use of lithium batteries, the protection board needs to be tested before leaving the factory to ensure that the performance of the protection board meets the requirements.

[0003] The protection board test instrument of the utility model is made by using the existing technology. The voltage simulation regulator usually includes two power supplies, a step-down power supply and a voltmeter. The two power supplies increase the cost of the test instrument and increase the installation space. The existing multi-string lithium battery protection board test instrument takes a long time to test, has low efficiency, and the maximum test current of the test instrument is only less than 200A, which cannot test the performance of the protection board under a larger current. Utility Model Content

[0004] According to one aspect of the utility model, a lithium battery voltage simulation regulator is provided, which is applied to a multi-string lithium battery pack protection board test device, comprising:

[0005] An adjustable voltage-stabilized power supply, which is connected to an external AC power supply to rectify and step down the external AC power supply into a DC power supply output;

[0006] A voltage regulating circuit, connected to the adjustable regulated power supply, and configured to enable the adjustable regulated power supply to output a first voltage, a second voltage, or a third voltage;

[0007] A selection switch connected to the voltage regulating circuit, used for selecting the output of the first voltage, the second voltage or the third voltage;

[0008] A step-down circuit is connected in series between the output end of the voltage regulating circuit and the detection voltage end, and is used to step down the first voltage to the undervoltage test voltage of the lithium battery pack and output it from the detection voltage end, step down the second voltage to the working test voltage of the lithium battery pack and output it from the detection voltage end, and step down the third voltage to the overvoltage test voltage of the lithium battery and output it from the detection voltage end;

[0009] The first voltage, the second voltage and the third voltage also power a voltmeter for displaying a voltage value of the detection voltage terminal.

[0010] In some embodiments, the voltage regulating circuit includes a resistor R0, an optocoupler G1, a voltage stabilizing circuit, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a potentiometer W;

[0011] One end of the resistor R0 is connected to the positive electrode of the adjustable voltage-stabilized power supply, and the other end is connected to the first end of the optical coupler G1;

[0012] The second end of the optical coupler G1 is connected to the voltage stabilizing circuit, and the third end and the fourth end of the optical coupler G1 are connected to the adjustable voltage stabilizing power supply;

[0013] The voltage stabilizing circuit is connected to the negative electrode of the adjustable voltage stabilizing power supply;

[0014] The resistor R1 and the resistor R2 are connected in series and then in parallel at both ends of the adjustable voltage-stabilized power supply, and the connecting end of the resistor R1 and the resistor R2 is also connected to the voltage-stabilizing circuit;

[0015] One end of the resistor R3 is connected to the connection end of the resistor R1 and the resistor R2, and the other end is connected to the movable end of the potentiometer W;

[0016] The first fixed end of the potentiometer W is connected to the positive electrode of the adjustable voltage-stabilized power supply, and the other end is connected to the negative electrode of the adjustable voltage-stabilized power supply via a resistor R4.

[0017] In some embodiments, the voltage stabilizing circuit is a voltage stabilizing chip;

[0018] The second end of the optical coupler G1 is connected to the cathode of the voltage stabilizing chip, and the anode of the voltage stabilizing chip is connected to the negative electrode of the adjustable voltage stabilizing power supply;

[0019] The connection end of the resistor R1 and the resistor R2 is also connected to the reference electrode of the voltage stabilizing chip.

[0020] In some embodiments, the selection switch includes a common terminal, a first branch terminal, a second branch terminal, and a third branch terminal;

[0021] The common end is connected to the other end of the resistor R3;

[0022] The first branch end is connected to the negative electrode of the adjustable voltage-stabilized power supply;

[0023] The second branch end is suspended;

[0024] The third branch end is connected to one end of the resistor R4.

[0025] In some embodiments, when the common terminal of the selection switch is connected to the first branch terminal, the voltage regulating circuit outputs the first voltage;

[0026] When the common end of the selection switch is connected to the second branch end, the voltage regulating circuit outputs the second voltage;

[0027] When the common end of the selection switch is connected to the third branch end, the voltage regulating circuit outputs the third voltage.

[0028] In some embodiments, the step-down circuit is a step-down chip;

[0029] The cathode of the step-down chip is connected to the positive electrode of the output end of the voltage regulating circuit, and the anode of the step-down chip is connected to the positive electrode of the detection voltage end;

[0030] The cathode of the buck chip is connected to its reference electrode;

[0031] After the first voltage, the second voltage or the third voltage of the step-down chip is reduced by a fixed value, it is output to the detection voltage terminal.

[0032] In some embodiments, the positive electrode of the voltmeter is connected to the output end of the voltage regulating circuit;

[0033] The detection input terminal of the voltmeter is connected to the positive electrode of the detection voltage terminal;

[0034] The first voltage, the second voltage and the third voltage are all within the power supply voltage range of the voltmeter to supply power to it.

[0035] According to a second aspect of the present invention, a multi-string lithium battery pack protection board testing device is provided, comprising:

[0036] Multiple lithium battery voltage analog regulators as described in any one of the above items;

[0037] The multi-way connector is used to connect with the protection board to connect the protection board to the test equipment, so that the protection board is connected with the lithium battery voltage simulation regulator, and then the protection board is tested.

[0038] In some embodiments, it further comprises:

[0039] The lithium battery pack is connected to the protection board through a voltage acquisition multi-way connector;

[0040] A discharge load group, connected to the lithium battery group, including multiple parallel load branches;

[0041] The main electronic switch is used to control the on-off of the series main circuit, that is, to turn on or off the discharge current of the lithium battery group through the discharge load group and the protection board.

[0042] In some embodiments, each of the load branches includes a discharge resistor and a relay switch connected in series, and a plurality of the load branches are connected in parallel and connected to the main electronic switch.

[0043] The beneficial effects of the utility model: the lithium battery voltage simulation regulator and multi-string lithium battery protection board test equipment of the utility model can quickly select three voltage levels for testing through a selection switch, and the voltage test is faster and more efficient; the voltage simulation regulator can simultaneously provide the test voltage and the voltage for the voltmeter, reducing the cost and installation location of a power supply, and the test equipment is equipped with multiple parallel load branches, which can combine more test current values, and can support current testing in the range of 50A-2500A, meeting the performance test requirements of the protection board at more current levels. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A circuit diagram of a lithium battery voltage analog regulator according to some embodiments of the present invention;

[0045] Figure 2 A schematic diagram of a circuit for connecting multiple lithium battery voltage analog regulators in some embodiments of the utility model;

[0046] Figure 3 A circuit diagram of a multi-string lithium battery pack protection board testing device according to some embodiments of the present invention;

[0047] Figure 4 This is a circuit diagram of relay coils and contacts of a multi-string lithium battery pack protection board testing device in some embodiments of the present invention. DETAILED DESCRIPTION

[0048] The utility model is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0049] It should be noted that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0050] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0052] In the above description, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0053] like Figures 1 to 4As shown, the present embodiment discloses a multi-string lithium battery pack protection board test device, including a multi-channel lithium battery voltage simulation regulator, a lithium battery pack, a discharge load group, a multi-channel connector, a voltage acquisition multi-channel connector, a main electronic switch, a test voltmeter, and a test ammeter, wherein the multi-channel connector is used to connect to the protection board to connect the protection board to the test equipment so that the protection board lithium battery voltage simulation regulator is connected; the lithium battery voltage simulation regulator is used to test the voltage protection function of the protection board (including protection under the working voltage of the lithium battery, undervoltage protection, and overvoltage protection); the voltage acquisition multi-channel connector is used to connect the lithium battery pack to the protection board, and the circuit composed of the lithium battery pack and the discharge load group is used to test the current protection function of the protection board; the main electronic switch is used to turn on the discharge current of the lithium battery pack through the discharge load group and the protection board; the test voltmeter and the test ammeter are used to display the test voltage value and the test current value during the test.

[0054] like Figure 1 As shown, specifically, the lithium battery voltage analog regulator includes an adjustable regulated power supply, a voltage regulating circuit, a selection switch K, a step-down circuit and a voltmeter. The adjustable regulated power supply is connected to an external AC power supply (which can be a 220V AC power supply of the mains) to step down and rectify the external AC power supply into a DC power supply output.

[0055] like Figure 1 As shown, the voltage regulating circuit is connected to the adjustable regulated power supply and is used to regulate the voltage output by the adjustable regulated power supply so that the adjustable regulated power supply outputs a first voltage, a second voltage or a third voltage. In this embodiment, the first voltage can be set to 4.5V, the second voltage can be any voltage value between 4.5V and 6.8V, and the third voltage can be set to 7.0V.

[0056] like Figure 1 As shown, specifically, the voltage regulating circuit includes a resistor R0, an optical coupler G1, a voltage stabilizing circuit, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a potentiometer W; one end of the resistor R0 is connected to the positive electrode of the adjustable voltage-stabilized power supply, and the other end is connected to the first end of the optical coupler G1; the second end of the optical coupler G1 is connected to the voltage stabilizing circuit, and the third and fourth ends of the optical coupler G1 are connected to the adjustable voltage-stabilized power supply; the voltage stabilizing circuit is connected to the negative electrode of the adjustable voltage-stabilized power supply; the resistor R1 and the resistor R2 are connected in series and then in parallel at both ends of the adjustable voltage-stabilized power supply, and the connection end of the resistor R1 and the resistor R2 is also connected to the voltage stabilizing circuit; one end of the resistor R3 is connected to the connection end of the resistor R1 and the resistor R2, and the other end is connected to the movable end of the potentiometer W; the first fixed end of the potentiometer W is connected to the positive electrode of the adjustable voltage-stabilized power supply, and the other end is connected to the negative electrode of the adjustable voltage-stabilized power supply through the resistor R4.

[0057] like Figure 1As shown, more specifically, the voltage stabilizing circuit can be a voltage stabilizing chip IC1, and the voltage stabilizing chip can adopt TL431. The second end of the optocoupler G1 is connected to the cathode K of the voltage stabilizing chip IC1, and the anode A of the voltage stabilizing chip IC1 is connected to the negative electrode of the adjustable regulated power supply; the connection end of the resistor R1 and the resistor R2 is also connected to the reference electrode R of the voltage stabilizing chip IC1.

[0058] like Figure 1 As shown, the selection switch K is connected to the voltage regulating circuit and is used to select the output of the first voltage, the second voltage or the third voltage; the selection switch K can be a toggle switch with three gears, and the selection switch K includes a common end, a first branch end, a second branch end and a third branch end; the common end is connected to the other end of the resistor R3; the first branch end is connected to the negative electrode of the adjustable voltage-stabilized power supply; the second branch end is suspended; and the third branch end is connected to one end of the resistor R4. The selection switch K will only connect one of the branches at the same time to output different voltages, as follows:

[0059] When the common terminal of the selection switch K is connected to the first branch terminal, the voltage regulating circuit outputs a first voltage, that is, the output voltage value is fixed to a first voltage of 4.5V;

[0060] When the common end of the selection switch K is connected to the second branch end, the voltage regulating circuit outputs a second voltage. The value of the second voltage can be adjusted by adjusting the movable end of the potentiometer W. The range of the second voltage is between 4.5V and 6.8V.

[0061] When the common terminal of the selection switch K is connected to the third branch terminal, the voltage regulating circuit outputs a third voltage, that is, the output voltage value is fixed to a third voltage of 7.0V.

[0062] The voltage range output by the lithium battery voltage simulation regulator needs to be less than the lowest voltage of the lithium battery and greater than the highest voltage range of the lithium battery. The voltage of existing iron-lithium batteries, ternary lithium batteries, etc. is in the range of 2.0V-4.5V. The aforementioned first voltage, second voltage and third voltage are greater than or equal to the voltage range of existing lithium batteries. Therefore, it is also necessary to use a step-down circuit to step down the first voltage, second voltage and third voltage before outputting them to the detection voltage end for testing.

[0063] like Figure 1As shown, the step-down circuit is connected in series between the output end of the voltage regulating circuit and the detection voltage end, and is used to step down the first voltage to the undervoltage test voltage of the lithium battery pack and output it from the detection voltage end, step down the second voltage to the working test voltage of the lithium battery pack and output it from the detection voltage end, and step down the third voltage to the overvoltage test voltage of the lithium battery and output it from the detection voltage end. The step-down circuit is a step-down chip IC2, and the step-down chip can be TL431; the cathode K of the step-down chip IC2 is connected to the positive electrode of the output end of the voltage regulating circuit, the anode A of the step-down chip IC2 is connected to the positive electrode of the detection voltage end, and the cathode K of the step-down chip IC2 is connected to the reference electrode R of the step-down chip IC2. The anode A of the step-down chip IC2 is also connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the negative electrode of the adjustable voltage-stabilized power supply.

[0064] After the first voltage, the second voltage or the third voltage is reduced by a fixed value through the step-down chip IC2, it is output to the detection voltage terminal. The step-down chip IC2 reduces the fixed value to 2.5V.

[0065] When the common end of the selection switch K is connected to the first branch end, the voltage regulating circuit outputs a first voltage (4.5V). After the first voltage is stepped down by 2.5V through the step-down chip IC2, the output voltage is the undervoltage test voltage (2.0V) of the lithium battery pack, thereby realizing the undervoltage protection function test of the protection board.

[0066] When the common end of the selection switch K is connected to the second branch end, the voltage regulating circuit outputs a second voltage (between 4.5V and 6.8V). After the second voltage is stepped down by 2.5V by the step-down chip IC2, the output voltage is the working test voltage of the lithium battery pack (between 2.0V and 4.3V), which can be adjusted within the working voltage range of the lithium battery, thereby realizing the protection function test of the protection board under the normal working voltage of the lithium battery.

[0067] When the common end of the selection switch K is connected to the third branch end, the voltage regulating circuit outputs the third voltage (7.0V). After the third voltage is stepped down by 2.5V by the step-down chip IC2, the output voltage is the lithium battery overvoltage test voltage, thereby realizing the overvoltage protection function test of the protection board.

[0068] The lithium battery voltage simulation regulator of this embodiment can quickly switch the output of the lithium battery pack undervoltage test voltage and the lithium battery overvoltage test voltage through the selection switch, quickly complete the test of the overvoltage protection and undervoltage protection functions, and then switch to the working voltage gear. The potentiometer W can be used to adjust and test several working voltage values ​​(in some scenarios, the test of the adjustable working voltage can even be omitted). The whole process only takes tens of seconds. When the existing test instrument performs a voltage test on the protection board, the voltage must slowly rise from undervoltage to working voltage and then to overvoltage. It is impossible to directly switch the voltage gear. The whole process is very time-consuming. It takes several minutes or even more than ten minutes to test a protection board. The test is time-consuming and inefficient. Compared with the prior art, the solution of this embodiment provides a voltage switching function to quickly test undervoltage and overvoltage protection, and can also switch to an adjustable working voltage gear. The specific working voltage value is tested through the potentiometer W, and the operation and control functions of the protection board can be quickly tested. It is efficient and saves test time.

[0069] like Figure 1 As shown, in order to facilitate the user to intuitively see the value of the working test voltage when adjusting the potentiometer W, a voltmeter for displaying the voltage value output by the detection voltage terminal is also provided. The voltmeter is a digital voltmeter, and its working voltage is above 4.5V. If the positive pole (V+) of the voltmeter is directly connected to the detection voltage terminal, when the output test voltage is 2.0V, the voltmeter cannot work. If another power supply is configured to power the voltmeter, the cost and installation position will be increased. Therefore, the positive pole of the voltmeter is connected to the output end of the voltage regulation circuit (that is, connected to the cathode K of the buck chip IC2), so that the voltmeter is powered by the voltage output by the voltage regulation circuit that has not been stepped down by the buck chip IC2, that is, the voltmeter is powered by the first voltage, the second voltage and the third voltage that have not been stepped down by the buck chip IC2, and the first voltage, the second voltage and the third voltage are all within the power supply voltage range of the voltmeter. The detection input terminal Vin of the voltmeter is connected to the positive pole of the detection voltage terminal, so that the voltage value of the detection voltage terminal is detected.

[0070] The lithium battery voltage simulation regulator of this embodiment is only provided with an adjustable regulated power supply, which outputs two different voltages through the cooperation of the voltage regulating circuit and the voltage step-down circuit. Taking the undervoltage branch as an example, the voltage has two output levels of 2.0V and 4.5V, of which 2.0V is used for the undervoltage function test of the protection board, and 4.5V is used for the power supply of the voltmeter. In the undervoltage level with the lowest voltage, the voltage can meet the power supply of the voltmeter, and in other levels, it can naturally meet the power supply of the voltmeter. Through such a setting, costs can be saved, the installation position of the circuit board can be saved, and it is conducive to the miniaturization of the circuit board.

[0071] In this embodiment, the circuit connection of the multi-channel lithium battery voltage analog regulator is as follows: Figure 2As shown, the detection voltage terminals of the multi-channel lithium battery voltage analog regulator are V1~Vn+1, the detection voltage terminals V1~Vn+1 are connected to the detection input terminal Vin of the voltmeter, and the negative pole of the voltmeter is connected to the V0 terminal of the test voltmeter. When the detection voltage terminal Vn of any channel is connected to the test point of the test voltmeter, the test voltmeter can read the total voltage between the Vn terminal and the V0 terminal.

[0072] The multi-string lithium battery pack protection board test equipment is preferably equipped with ten lithium battery voltage simulation regulators as described above, that is, it can support the test of the protection board of ten strings or less of lithium battery packs.

[0073] like Figure 3 As shown, when the protection board (i.e., the circuit board under test) is connected to the test equipment, the lithium battery pack, the protection board, the main electronic switch, and the discharge load group are connected in series. The lithium battery pack is used to discharge the discharge load group. The discharge load group includes multiple load branches connected in parallel at both ends of the lithium battery pack. After the multiple load branches are connected in parallel, they are connected to the main electronic switch. Each load branch includes a discharge resistor and relay switches J1~J10 connected in series.

[0074] When the contacts of the relay switch of one branch are closed, the contacts of the relay switches of other branches are opened, that is, the test current supported by the entire discharge load group is the current passing through the closed branch; when the contacts of the relay switches of multiple branches are closed, the test current supported by the entire discharge load group is the sum of the currents passing through multiple branches, thereby realizing multiple gears of test current to perform current protection test on the protection board.

[0075] The current passing through each load branch can be the same or different. As one example, there are ten load branches, of which four have a current of 400A, four have a current of 200A, one has a current of 100A, and one has a current of 50A. Different current settings can be achieved by adaptively adjusting the resistance of the discharge resistors of each branch. If the contacts of the relay switches J1~J10 of the ten branches are closed, the maximum test current can reach more than 2500A, which is much higher than the current that the existing test instruments can support. It can achieve the current protection performance of the protection board under the working conditions of a larger current.

[0076] like Figure 4 As shown, relay switches J1~J10 are connected in parallel at both ends of the power supply. The power supply can adopt a 12V power supply. The opening and closing of the contacts of each relay switch can be controlled by setting a toggle switch. The required test current gear can be combined by closing the corresponding one or more switches according to the needs.

[0077] like Figure 3As shown, the main electronic switch is used to control the on and off of the series main circuit, that is, to turn on or off the discharge current of the lithium battery pack through the discharge load group and the protection board. The main electronic switch is a resettable button switch. When the button is pressed during the test, the main electronic switch is closed, the main circuit can be connected, and the lithium battery pack can discharge the discharge load group and the protection board, and then the protection board is tested for normal current operation and multi-speed current protection. If only the contacts of the relay switch are closed but the main electronic switch is not closed, the lithium battery pack cannot supply power; the test current is greater than the number of closed relay switches, which can be set before the test or increased or decreased after pressing the button (the main electronic switch is closed). After the test is completed, release the button, the main electronic switch is disconnected, and the current of the lithium battery pack through the discharge load group and the protection board is turned off. The main electronic switch can also be other components that can control the on and off of the circuit, and this embodiment does not limit its specific structure.

[0078] like Figure 3 As shown, a current sensor is also connected to the series main circuit to collect the current value on the main circuit, which can then be displayed by a test ammeter.

[0079] The lithium battery voltage simulation regulator and multi-string lithium battery protection board test equipment of the utility model can quickly select three voltage levels for testing through a selection switch, and the voltage test is faster and more efficient; the voltage simulation regulator can provide the test voltage and the voltage for the voltmeter at the same time, reducing the cost and installation location of a power supply. In addition, the test equipment is equipped with multiple parallel load branches, which can combine more test current values, support current testing in the range of 50A-2500A, and meet the performance test requirements of the protection board under more current conditions.

[0080] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A lithium battery voltage analog regulator, applied to a multi-string lithium battery pack protection board test device, characterized in that: include: An adjustable voltage-stabilized power supply, which is connected to an external AC power supply to rectify and step down the external AC power supply into a DC power supply output; A voltage regulating circuit, connected to the adjustable regulated power supply, and configured to enable the adjustable regulated power supply to output a first voltage, a second voltage, or a third voltage; A selection switch connected to the voltage regulating circuit, used for selecting the output of the first voltage, the second voltage or the third voltage; A step-down circuit is connected in series between the output end of the voltage regulating circuit and the detection voltage end, and is used to step down the first voltage to the undervoltage test voltage of the lithium battery pack and output it from the detection voltage end, step down the second voltage to the working test voltage of the lithium battery pack and output it from the detection voltage end, and step down the third voltage to the overvoltage test voltage of the lithium battery and output it from the detection voltage end; The first voltage, the second voltage and the third voltage also power a voltmeter for displaying a voltage value of the detection voltage terminal.

2. The lithium battery voltage analog regulator according to claim 1, characterized in that: The voltage regulating circuit includes a resistor R0, an optical coupler G1, a voltage stabilizing circuit, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a potentiometer W; One end of the resistor R0 is connected to the positive electrode of the adjustable voltage-stabilized power supply, and the other end is connected to the first end of the optical coupler G1; The second end of the optical coupler G1 is connected to the voltage stabilizing circuit, and the third end and the fourth end of the optical coupler G1 are connected to the adjustable voltage stabilizing power supply; The voltage stabilizing circuit is connected to the negative electrode of the adjustable voltage stabilizing power supply; The resistor R1 and the resistor R2 are connected in series and then in parallel at both ends of the adjustable voltage-stabilized power supply, and the connecting end of the resistor R1 and the resistor R2 is also connected to the voltage-stabilizing circuit; One end of the resistor R3 is connected to the connection end of the resistor R1 and the resistor R2, and the other end is connected to the movable end of the potentiometer W; The first fixed end of the potentiometer W is connected to the positive electrode of the adjustable voltage-stabilized power supply, and the other end is connected to the negative electrode of the adjustable voltage-stabilized power supply via a resistor R4.

3. The lithium battery voltage analog regulator according to claim 2, characterized in that: The voltage stabilizing circuit is a voltage stabilizing chip; The second end of the optical coupler G1 is connected to the cathode of the voltage stabilizing chip, and the anode of the voltage stabilizing chip is connected to the negative electrode of the adjustable voltage stabilizing power supply; The connection end of the resistor R1 and the resistor R2 is also connected to the reference electrode of the voltage stabilizing chip.

4. The lithium battery voltage analog regulator according to claim 3, characterized in that: The selection switch includes a common terminal, a first branch terminal, a second branch terminal and a third branch terminal; The common end is connected to the other end of the resistor R3; The first branch end is connected to the negative electrode of the adjustable voltage-stabilized power supply; The second branch end is suspended; The third branch end is connected to one end of the resistor R4.

5. The lithium battery voltage analog regulator according to claim 4, characterized in that: When the common end of the selection switch is connected to the first branch end, the voltage regulating circuit outputs the first voltage; When the common end of the selection switch is connected to the second branch end, the voltage regulating circuit outputs the second voltage; When the common end of the selection switch is connected to the third branch end, the voltage regulating circuit outputs the third voltage.

6. The lithium battery voltage analog regulator according to claim 5, characterized in that: The step-down circuit is a step-down chip; The cathode of the step-down chip is connected to the positive electrode of the output end of the voltage regulating circuit, and the anode of the step-down chip is connected to the positive electrode of the detection voltage end; The cathode of the step-down chip is connected to its reference electrode; After the first voltage, the second voltage or the third voltage of the step-down chip is reduced by a fixed value, it is output to the detection voltage terminal.

7. The lithium battery voltage analog regulator according to claim 6, characterized in that: The positive electrode of the voltmeter is connected to the output end of the voltage regulating circuit; The detection input terminal of the voltmeter is connected to the positive electrode of the detection voltage terminal; The first voltage, the second voltage and the third voltage are all within the power supply voltage range of the voltmeter to supply power to it.

8. A multi-string lithium battery protection board testing device, characterized in that: include: A multi-channel lithium battery voltage analog regulator as described in any one of claims 1 to 7; The multi-way connector is used to connect with the protection board to connect the protection board to the test equipment, so that the protection board is connected with the lithium battery voltage simulation regulator, and then the protection board is tested.

9. The multi-string lithium battery protection board testing device according to claim 8, characterized in that: Also includes: The lithium battery pack is connected to the protection board through a voltage acquisition multi-way connector; A discharge load group, connected to the lithium battery group, including multiple parallel load branches; The main electronic switch is used to turn on or off the discharge current of the lithium battery pack through the discharge load group and the protection board.

10. The multi-string lithium battery protection board testing device according to claim 9, characterized in that: Each of the load branches includes a discharge resistor and a relay switch connected in series, and a plurality of the load branches are connected in parallel and then connected to the main electronic switch.

Images