Simple simulation lithium battery function circuit

Abstract

The invention discloses a simple simulation lithium battery function circuit which comprises a switching power supply circuit module, a power supply voltage stabilizing circuit module, a fan power supply circuit module, an overcurrent detection protection circuit module and a simulation lithium battery charging and discharging circuit module. The switching power supply circuit module is respectively connected with the power supply voltage stabilizing circuit module and the fan power supply circuit module and provides 12V voltage for the power supply voltage stabilizing circuit module and the fan power supply circuit module; the power supply voltage stabilizing circuit module is connected with the over-current detection protection circuit module and the simulation lithium battery charging and discharging circuit module and provides 5V voltage for the over-current detection protection circuit module and the simulation lithium battery charging and discharging circuit module. The fan power supply circuit module is connected with a fan and dissipates heat for a cooling fin integrated on the simulation lithium battery charging and discharging circuit module through the fan. And the over-current detection protection circuit module is connected with the simulation lithium battery charging and discharging circuit module and realizes a charging over-current protection effect.

Description

Technical Field

[0001] The invention relates to the field of electronic devices, and in particular to a simple lithium battery simulation function circuit. Background Art

[0002] Lithium batteries have been used in more and more fields. Their high energy density can ensure that the equipment has a long battery life with a small size and weight. In particular, consumer electronics control panels are equipped with lithium batteries. In order to adapt to the charging and discharging functions of lithium batteries, there are usually special lithium battery charging and discharging chips on the control panels. The time from a lithium battery to a fully charged state is generally long. When producing such control panels, if lithium batteries are used to verify the charging or discharging function of the chip, the production efficiency will be greatly reduced. And if each control panel uses lithium batteries to verify the charging and discharging functions, it is impossible to achieve mass production of the control panel.

[0003] Patent No. ZL201820362483.3 discloses a simulation circuit for lithium battery charging and discharging. Although it can achieve the simulation effect of lithium battery charging and discharging, it does not have an overcurrent protection function. When performing charge and discharge simulation operations, overcurrent is very likely to occur, which affects the safety of the product; at the same time, in the charge and discharge simulation circuit of this structure, each circuit component is expensive, which increases its production cost, and it is necessary to improve it. Summary of the invention

[0004] The object of the present invention is to provide a simple lithium battery simulation function circuit which can effectively improve the control board testing efficiency in view of the above problems.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A simple simulated lithium battery functional circuit comprises a switching power supply circuit module, a power supply voltage stabilizing circuit module, a fan power supply circuit module, an overcurrent detection protection circuit module, and a simulated lithium battery charging and discharging circuit module; the switching power supply circuit module is respectively connected to the power supply voltage stabilizing circuit module and the fan power supply circuit module and provides a 12V voltage to the power supply voltage stabilizing circuit module and the fan power supply circuit module; the power supply voltage stabilizing circuit module is respectively connected to the overcurrent detection protection circuit module and the simulated lithium battery charging and discharging circuit module and provides a 5V voltage to the overcurrent detection protection circuit module and the simulated lithium battery charging and discharging circuit module; the fan power supply circuit module is connected to a fan and dissipates heat for a heat sink integrated on the simulated lithium battery charging and discharging circuit module through the fan; the overcurrent detection protection circuit module is connected to the simulated lithium battery charging and discharging circuit module and realizes a charging overcurrent protection effect.

[0007] Furthermore, the switching power supply circuit module includes a rectifier BD1 and a switching power supply chip U3. The first pin of the rectifier BD1 is connected to one end of the capacitor CX1 and the live wire through the inductor LF1. The second pin of the rectifier BD1 is connected to the other end of the capacitor CX1 and the neutral wire through the inductor LF1. The third pin of the rectifier BD1 is respectively connected to one end of the capacitor EC7, one end of the resistor R25, one end of the capacitor C10, and one end of the transformer coil TR1A. The fourth pin of the rectifier BD1 and the other end of the capacitor EC7 are connected to the live wire. One end is grounded; the other end of the resistor R25 and the other end of the capacitor C10 are connected to one end of the resistor R24, the other end of the resistor R24 ​​is connected to the cathode of the diode D1, the anode of the diode D1 and the other end of the transformer coil TR1A are connected to the SW pin of the switching power supply chip U3, the VDD pin of the switching power supply chip U3 is respectively connected to one end of the capacitor C12, one end of the capacitor EC8, and one end of the resistor R29, the other end of the resistor R29 is connected to one end of the diode D3, and the diode D3 The other end of the resistor R30 is respectively connected to one end of the resistor R30 and one end of the transformer coil TR1B, and the other end of the transformer coil TR1B, the other end of the capacitor C12, and the other end of the capacitor EC8 are all grounded; the other end of the resistor R30 is respectively connected to the FB pin of the switching power supply chip U3, one end of the resistor R31, and one end of the resistor R32, the CS pin of the switching power supply chip U3 is respectively connected to one end of the resistor R33 and one end of the resistor R42, the other end of the resistor R31, the other end of the resistor R32, and the CS pin of the switching power supply chip U3 are respectively connected to one end of the resistor R33 and one end of the resistor R42, The other end, the other end of the resistor R42, and the GND pin of the switching power supply chip U3 are all grounded; one end of the transformer coil TR1C is respectively connected to one end of the resistor R28 and the anode of the diode D2, the other end of the resistor R28 is connected to one end of the capacitor C11, the other end of the capacitor C11 and the cathode of the diode D2 are all connected to one end of the capacitor EC9, the 12V voltage interface, and one end of the resistor R27, the other end of the transformer coil TR1C, the other end of the capacitor EC9, and the other end of the resistor R27 are all grounded.

[0008] Furthermore, the power supply voltage stabilizing circuit module includes a transistor Q8, the collector of the transistor Q8, one end of the resistor R35, one end of the capacitor EC3, and one end of the capacitor C5 are all connected to the 12V voltage interface, the other end of the resistor R35 and the base of the transistor Q8 are all connected to the cathode of the voltage stabilizing diode, the emitter of the transistor Q8 and one end of the capacitor EC4 are all connected to the 5V voltage stabilizing interface, and the anode of the voltage stabilizing diode, the other end of the capacitor EC3, the other end of the capacitor C5, and the other end of the capacitor EC4 are all grounded.

[0009] Furthermore, the fan power supply circuit module includes a step-down chip U5, the VIN pin of the step-down chip U5 is respectively connected to the 12V voltage interface, one end of the capacitor EC5, one end of the resistor R3, and one end of the capacitor C7, the other end of the resistor R3 is connected to the EN pin of the step-down chip U5, and the other end of the capacitor EC5 and the other end of the capacitor C7 are both grounded; the SW pin of the step-down chip U5 is respectively connected to one end of the capacitor C8 and one end of the inductor L1, the other end of the capacitor C8 is connected to the BST pin of the step-down chip U5, the other end of the inductor L1 is respectively connected to one end of the resistor R21, the VCC terminal, one end of the capacitor EC6, and the first pin of the fan connector, the other end of the resistor R21 and the FB pin of the step-down chip U5 are both connected to one end of the resistor R22, the other end of the resistor R22, the other end of the capacitor EC6, the second pin of the fan connector, and the GND pin of the step-down chip U5 are all grounded.

[0010] Furthermore, the overcurrent detection protection circuit module includes a first detection chip U6, a second detection chip U4, an operational amplifier U7A, and an operational amplifier U7B; the V+ pin of the first detection chip U6 and one end of the capacitor C9 are connected to the 5V voltage regulator interface, the other end of the capacitor C9, the REF pin of the first detection chip U6, and the GND pin of the first detection chip U6 are all grounded, the OUT pin of the first detection chip U6 is connected to the positive input port of the operational amplifier U7A, and the IN- pin and IN+ pin of the first detection chip U6 are connected to the simulated lithium battery charging and discharging The second detection chip U4 is connected to the electrical circuit module; the V+ pin of the second detection chip U4 and one end of the capacitor C15 are connected to the 5V voltage regulator interface, the other end of the capacitor C15, the REF pin of the second detection chip U4, and the GND pin of the second detection chip U4 are grounded, the OUT pin of the second detection chip U4 is connected to the positive input port of the operational amplifier U7B, and the IN- pin and IN+ pin of the second detection chip U4 are connected to the analog lithium battery charge and discharge circuit module; the negative input port of the operational amplifier U7A is respectively connected to the negative input port, One end of the resistor R40 and one end of the resistor R41 are connected, the other end of the resistor R40 is connected to the simulated lithium battery charging and discharging circuit module, and the other end of the resistor R41 is grounded; the positive power supply port of the operational amplifier U7A is respectively connected to the 5V voltage regulator interface and one end of the capacitor C14, and the other end of the capacitor C14 and the negative power supply port of the operational amplifier U7A are both grounded; the output port of the operational amplifier U7A is connected to one end of the resistor R39, and the other end of the resistor R39 is respectively connected to one end of the resistor R38 and the base of the transistor Q6, and the other end of the resistor R38 , the emitters of the transistor Q6 are grounded, and the collector of the transistor Q6 is connected to the simulated lithium battery charge and discharge circuit module; the positive power supply port of the operational amplifier U7B is connected to the 5V voltage regulator interface, and the negative power supply port of the operational amplifier U7B is grounded; the output port of the operational amplifier U7B is connected to one end of the resistor R36, and the other end of the resistor R36 is respectively connected to one end of the resistor R37 and the base of the transistor Q7, the other end of the resistor R37 and the emitter of the transistor Q7 are grounded, and the collector of the transistor Q7 is connected to the simulated lithium battery charge and discharge circuit module.

[0011] Furthermore, the analog lithium battery charging and discharging circuit module includes an operational amplifier U1A and an operational amplifier U1B, the negative input port of the operational amplifier U1A is respectively connected to the positive input port of the operational amplifier U1B, one end of the resistor R9, and one end of the variable resistor, the other end of the resistor R9 is grounded, and the other end of the variable resistor is respectively connected to the collector of the transistor Q2, one end of the capacitor C3, one end of the capacitor EC2, the IN+ pin of the first detection chip U6, the IN- pin of the second detection chip U4, one end of the resistor R18, one end of the resistor R19, the emitter of the transistor Q5, the emitter of the transistor Q4, and one end of the resistor R17, the other end of the resistor R18 and the other end of the resistor R19 They are all connected to the IN- pin of the first detection chip U6, the IN+ pin of the second detection chip U4, and the first pin of the detection interface, and the second pin of the detection interface, the other end of the capacitor C3, the other end of the capacitor EC1, and the other end of the capacitor EC2 are all grounded; the positive input port of the operational amplifier U1A is respectively connected to one end of the resistor R5, one end of the resistor R6, and one end of the capacitor C2, the other end of the capacitor R6 and the other end of the capacitor C2 are both grounded, the other end of the resistor R5 is respectively connected to one end of the resistor R4 and the positive input port of the operational amplifier U1B, the other end of the resistor R4 is respectively connected to one end of the resistor R40, one end of the resistor R1, one end of the voltage stabilizing source U2, and one end of the capacitor C13, and the stabilizing The other end of the voltage source U2 and the other end of the capacitor C13 are both grounded, and the other end of the resistor R1 is connected to the 5V voltage stabilization interface; the positive power supply port of the operational amplifier U1A is respectively connected to the 5V voltage stabilization interface and one end of the capacitor C1, the emitter of the transistor Q2 is respectively connected to the 12V voltage interface, one end of the capacitor EC1, and one end of the resistor R14, the other end of the capacitor EC1, the other end of the capacitor C1, and the negative power supply port of the operational amplifier U1A are all grounded; the output port of the operational amplifier U1A is respectively connected to the collector of the transistor Q6, the anode of the indicator light LED1, and one end of the resistor R11, the cathode of the indicator light LED1 is connected to one end of the resistor R26, and the other end of the resistor R26 is connected ground; the other end of the resistor R11 is respectively connected to one end of the resistor R12 and the base of the transistor Q1, the emitter of the transistor Q1 and the other end of the resistor R12 are both grounded, the collector of the transistor Q1 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to the other end of the resistor R14 and the base of the transistor Q2; the positive power supply port of the operational amplifier U1B is connected to the 5V voltage stabilizing interface, the negative power supply port of the operational amplifier U1B is grounded, the output port of the operational amplifier U1B is respectively connected to the collector of the transistor Q7, the anode of the indicator light LED3, and one end of the resistor R7, the cathode of the indicator light LED3 is connected to one end of the resistor R34, and the other end of the resistor R34 is grounded;The other end of the resistor R7 is connected to one end of the resistor R8 and the base of the transistor Q3 respectively. The emitter of the transistor Q3 and the other end of the resistor R8 are grounded. The collector of the transistor Q3 is connected to one end of the resistor R20. The other end of the resistor R20 is connected to the other end of the resistor R17, the base of the transistor Q4 and the base of the transistor Q5 respectively. The collector of the transistor Q4 and the collector of the transistor Q5 are grounded. ;

[0012] Furthermore, the transistor Q2, the transistor Q4, and the transistor Q5 are integrated on the same heat sink and are directly cooled by a fan connected to a fan connector.

[0013] Compared with the prior art, the present invention has the following advantages and positive effects:

[0014] 1. The circuit components used in the simulation circuit of the present invention are all conventional materials, which are easy to purchase and inexpensive, effectively reducing the production cost of the lithium battery charging and discharging simulation circuit;

[0015] 2. The simulation circuit in the present invention utilizes the characteristics of the operational amplifier comparator to simulate the discharge and charge functions of the lithium battery; when verifying the charge, it utilizes the characteristics of the transistor in the amplification region to make the current passing through larger and wider, and ensure the accuracy of the charging current value; it truly simulates the charging and discharging performance of the lithium battery, greatly shortens the test time of the control board, improves the production efficiency of the control board, and enables it to realize industrial production operations;

[0016] 3. The energy source of the simulated lithium battery in the present invention is a switching power supply circuit module, which can be directly connected to the 220V mains for use, without the need to specifically find a 12V DC power supply, and the switching power supply circuit module itself also has over-temperature and over-voltage protection functions. Once the circuit function is abnormal, the switching power supply circuit module will quickly enter the protection state, and return to the normal state after the abnormality is resolved;

[0017] 4. The analog circuit in the present invention uses a special current detection chip for protection during the charging and discharging process. Once an overcurrent occurs, the output can be quickly disconnected to ensure that the safety of products such as the control board is not affected. At the same time, the switching power supply circuit module in the analog circuit also has an overcurrent protection function, which effectively realizes double overcurrent protection during the test process and further improves the safety of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 is a circuit diagram of a switching power supply circuit module;

[0020] Figure 2 It is a circuit diagram of a power supply voltage stabilizing circuit module;

[0021] Figure 3 A circuit diagram of a fan power supply circuit module;

[0022] Figure 4 is a circuit connection diagram of the first detection chip U6;

[0023] Figure 5 is a circuit connection diagram of the second detection chip U4;

[0024] Figure 6 It is the circuit connection diagram of operational amplifiers U7A and U7B;

[0025] Figure 7 This is a circuit diagram for simulating the lithium battery charging and discharging circuit module. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0027] like Figures 1 to 7As shown, this embodiment discloses a simple simulated lithium battery functional circuit, including a switching power supply circuit module, a power supply voltage stabilizing circuit module, a fan power supply circuit module, an overcurrent detection protection circuit module, and a simulated lithium battery charging and discharging circuit module; the switching power supply circuit module is respectively connected to the power supply voltage stabilizing circuit module and the fan power supply circuit module and provides a 12V voltage to the power supply voltage stabilizing circuit module and the fan power supply circuit module; the power supply voltage stabilizing circuit module is respectively connected to the overcurrent detection protection circuit module and the simulated lithium battery charging and discharging circuit module and provides a 5V voltage to the overcurrent detection protection circuit module and the simulated lithium battery charging and discharging circuit module; the fan power supply circuit module is connected to the fan and dissipates heat for the heat sink integrated on the simulated lithium battery charging and discharging circuit module through the fan; the overcurrent detection protection circuit module is connected to the simulated lithium battery charging and discharging circuit module and realizes the charging overcurrent protection effect.

[0028] like Figure 1 As shown, the switching power supply circuit module can meet the input conditions of 90V~264VAC, and the rated output is 12V1A; U3 is the switching power supply main control PWM chip, with built-in MOS tube; CX1, LF1 form the front-stage EMI circuit; BD1, EC7 are the primary rectifier circuit; D1, R25, C10, R24 form the RCD circuit to absorb the peak voltage generated by the transformer; TR1B, D3, R29, EC8, C12 provide a stable VDD voltage for chip U3 to ensure the normal operation of the chip. R30, R31, R32 are the feedback voltage, and adjusting this resistor can change the output voltage of 12V; R33, R42 are the current limiting resistors of chip U3 (CS pin), which play an overcurrent protection role; D2, EC9, R27 are the secondary rectifier filter circuit, which converts the energy of the secondary TR1C into a stable DC 12V voltage.

[0029] The specific structure of the switching power supply circuit module includes a rectifier BD1 and a switching power supply chip U3. The first pin of the rectifier BD1 is connected to one end of the capacitor CX1 and the live wire through the inductor LF1. The second pin of the rectifier BD1 is connected to the other end of the capacitor CX1 and the neutral wire through the inductor LF1. The third pin of the rectifier BD1 is respectively connected to one end of the capacitor EC7, one end of the resistor R25, one end of the capacitor C10, and one end of the transformer coil TR1A. The fourth pin of the rectifier BD1 and the other end of the capacitor EC7 are connected to the live wire. One end is grounded; the other end of the resistor R25 and the other end of the capacitor C10 are connected to one end of the resistor R24, the other end of the resistor R24 ​​is connected to the cathode of the diode D1, the anode of the diode D1 and the other end of the transformer coil TR1A are connected to the SW pin of the switching power supply chip U3, the VDD pin of the switching power supply chip U3 is respectively connected to one end of the capacitor C12, one end of the capacitor EC8, and one end of the resistor R29, the other end of the resistor R29 is connected to one end of the diode D3, and the diode D3 The other end of the resistor R30 is respectively connected to one end of the resistor R30 and one end of the transformer coil TR1B, and the other end of the transformer coil TR1B, the other end of the capacitor C12, and the other end of the capacitor EC8 are all grounded; the other end of the resistor R30 is respectively connected to the FB pin of the switching power supply chip U3, one end of the resistor R31, and one end of the resistor R32, the CS pin of the switching power supply chip U3 is respectively connected to one end of the resistor R33 and one end of the resistor R42, the other end of the resistor R31, the other end of the resistor R32, and the CS pin of the switching power supply chip U3 are respectively connected to one end of the resistor R33 and one end of the resistor R42, The other end, the other end of the resistor R42, and the GND pin of the switching power supply chip U3 are all grounded; one end of the transformer coil TR1C is respectively connected to one end of the resistor R28 and the anode of the diode D2, the other end of the resistor R28 is connected to one end of the capacitor C11, the other end of the capacitor C11 and the cathode of the diode D2 are all connected to one end of the capacitor EC9, the 12V voltage interface, and one end of the resistor R27, the other end of the transformer coil TR1C, the other end of the capacitor EC9, and the other end of the resistor R27 are all grounded.

[0030] like Figure 2 As shown, the power supply voltage stabilizing circuit module converts the 12V voltage output by the switching power supply circuit module into a stable 5V voltage after passing through Q8 and the voltage stabilizing diode. This 5V voltage is mainly used to power the operational amplifier LMV358, the current detection chip INA199 and the TL431 voltage stabilizing circuit, so the required current is not large. The use of this transistor voltage stabilizing circuit can meet the design needs while reducing the design cost.

[0031] The specific structure of the power supply voltage stabilization circuit module includes transistor Q8, the collector of the transistor Q8, one end of the resistor R35, one end of the capacitor EC3, and one end of the capacitor C5 are all connected to the 12V voltage interface, the other end of the resistor R35 and the base of the transistor Q8 are all connected to the cathode of the voltage stabilizing diode, the emitter of the transistor Q8 and one end of the capacitor EC4 are all connected to the 5V voltage stabilizing interface, and the anode of the voltage stabilizing diode, the other end of the capacitor EC3, the other end of the capacitor C5, and the other end of the capacitor EC4 are all grounded.

[0032] like Figure 3 As shown, the fan power supply circuit module converts the 12V voltage output by the switching power supply circuit module into another 5V800mA circuit through chip U5. This 5V voltage is mainly used to power the fan. The fan blows towards the heat sink of the transistor (TIP147), thereby reducing the temperature of the transistor and ensuring the normal operation of the circuit. By adjusting the resistors R21 and R22, the 5V voltage can be output stably.

[0033] The specific structure of the fan power supply circuit module includes a buck chip U5, the VIN pin of the buck chip U5 is respectively connected to the 12V voltage interface, one end of the capacitor EC5, one end of the resistor R3, and one end of the capacitor C7, the other end of the resistor R3 is connected to the EN pin of the buck chip U5, and the other end of the capacitor EC5 and the other end of the capacitor C7 are both grounded; the SW pin of the buck chip U5 is respectively connected to one end of the capacitor C8 and one end of the inductor L1, the other end of the capacitor C8 is connected to the BST pin of the buck chip U5, the other end of the inductor L1 is respectively connected to one end of the resistor R21, the VCC terminal, one end of the capacitor EC6, and the first pin of the fan connector, the other end of the resistor R21 and the FB pin of the buck chip U5 are both connected to one end of the resistor R22, the other end of the resistor R22, the other end of the capacitor EC6, the second pin of the fan connector, and the GND pin of the buck chip U5 are all grounded.

[0034] like Figure 4 , Figure 5 , Figure 6 As shown, U4 and U6 are the same type of current detection chip (INA199), which has a bidirectional current detection function; IN+ and IN- are connected to the two ends of the current sampling resistor respectively. VREF is a 2.5V voltage generated by 5V voltage after being stabilized by TL431; the built-in op amp of INA199 has a fixed amplification factor (50 times). After the voltage of IN+ and IN- is fixedly amplified by 50 times, it enters the + pole of op amp U7 and is compared with the voltage divider value of VREF R40 and R41.

[0035] For example: when simulating the discharge of a lithium battery, IN+ and IN- are connected to pins 4 and 5 of chip U6 respectively. Chip U6 outputs a fixed voltage that is amplified 50 times and then connected to pin 3 of chip U7. When the discharge current increases, the voltage difference between IN+ and IN- increases, and the output of pin 6 of U6 also increases. When the voltage is higher than the voltage divider value of VREF, pin 1 of chip U7 outputs a high voltage, and transistor Q6 is turned on, which in turn turns off Q1 and finally Q2. In this way, the discharge process of a lithium battery can be simulated.

[0036] Similarly, when the simulated lithium battery is charged, the direction of the current is reversed, that is, IN+ and IN- are connected to pins 5 and 4 of chip U4 respectively. U4 also outputs an amplified voltage of 50 times the voltage, which is then connected to pin 5 of chip U7. During the simulated charging process, the charging current becomes larger and larger, and the voltage at pin 5 also becomes larger and larger. When the voltage is higher than the voltage divider value of VREF, chip U7 outputs a high voltage, then Q7 is turned on, Q3 is turned off, and then Q4 and Q5 are turned off to prevent the charging current from being too large, thus playing a role of overcurrent protection.

[0037] The specific structure of the overcurrent detection protection circuit module includes a first detection chip U6, a second detection chip U4, an operational amplifier U7A, and an operational amplifier U7B; the V+ pin of the first detection chip U6 and one end of the capacitor C9 are connected to the 5V voltage regulator interface, the other end of the capacitor C9, the REF pin of the first detection chip U6, and the GND pin of the first detection chip U6 are all grounded, the OUT pin of the first detection chip U6 is connected to the positive input port of the operational amplifier U7A, and the IN- pin and IN+ pin of the first detection chip U6 are connected to the simulated lithium battery charging and discharging The second detection chip U4 is connected to the electrical circuit module; the V+ pin of the second detection chip U4 and one end of the capacitor C15 are connected to the 5V voltage regulator interface, the other end of the capacitor C15, the REF pin of the second detection chip U4, and the GND pin of the second detection chip U4 are grounded, the OUT pin of the second detection chip U4 is connected to the positive input port of the operational amplifier U7B, and the IN- pin and IN+ pin of the second detection chip U4 are connected to the analog lithium battery charge and discharge circuit module; the negative input port of the operational amplifier U7A is respectively connected to the negative input port, One end of the resistor R40 and one end of the resistor R41 are connected, the other end of the resistor R40 is connected to the simulated lithium battery charging and discharging circuit module, and the other end of the resistor R41 is grounded; the positive power supply port of the operational amplifier U7A is respectively connected to the 5V voltage regulator interface and one end of the capacitor C14, and the other end of the capacitor C14 and the negative power supply port of the operational amplifier U7A are both grounded; the output port of the operational amplifier U7A is connected to one end of the resistor R39, and the other end of the resistor R39 is respectively connected to one end of the resistor R38 and the base of the transistor Q6, and the other end of the resistor R38 , the emitters of the transistor Q6 are grounded, and the collector of the transistor Q6 is connected to the simulated lithium battery charge and discharge circuit module; the positive power supply port of the operational amplifier U7B is connected to the 5V voltage regulator interface, and the negative power supply port of the operational amplifier U7B is grounded; the output port of the operational amplifier U7B is connected to one end of the resistor R36, and the other end of the resistor R36 is respectively connected to one end of the resistor R37 and the base of the transistor Q7, the other end of the resistor R37 and the emitter of the transistor Q7 are grounded, and the collector of the transistor Q7 is connected to the simulated lithium battery charge and discharge circuit module.

[0038] like Figure 7 As shown, the 5V voltage generates a stable 2.5V voltage after passing through U2 (TL431), and then is divided by R4, R5, and R6 and connected to the 6th and 3rd pins of U1 (LMV358) respectively;

[0039] When simulating lithium battery discharge, U1A op amp works, U1B op amp does not work, R11, R12, R13, R14, Q1, Q2 form a discharge circuit. After power-on, the voltage of pin 3 of U1A is high, and the voltage of pin 2 is low, so U1A outputs a high voltage at this time; because pin 5 of U1B is low and pin 6 is high, U1B outputs a low voltage; when U1A outputs high, LED1 lights up green, Q1 transistor is turned on, and then Q2 is turned on, and the voltage of EC2 increases; when the voltage of pin 2 and pin 3 of U1A is equal, J1 outputs a stable simulated lithium battery voltage; due to the existence of resistor R5, the voltage of pin 6 of op amp U1B must be greater than the voltage of pin 3 of op amp U1A, so when simulating the discharge function, pin 7 of U1B will not output a high voltage.

[0040] When simulating lithium battery charging, U1A op amp does not work, U1B op amp works, R7, R8, R17, R20, Q3, Q4 form a charging circuit. When being charged, U1B's 5-pin input is high, greater than U1B's 6-pin, U1B's 7-pin outputs a high voltage, LED3 red light will light up, Q3 will turn on, and then Q4 will turn on; when discharging, transistor Q4 works in the amplification area, so the same model Q5 is connected in parallel to dissipate heat; and Q2, Q4, Q5 are integrated on a heat sink for heat dissipation, and a 5V fan blows directly on the heat sink to reduce the temperature of the transistor to ensure stable charging or discharging status.

[0041] The specific structure of the simulated lithium battery charging and discharging circuit module includes an operational amplifier U1A and an operational amplifier U1B. The negative input port of the operational amplifier U1A is respectively connected to the positive input port of the operational amplifier U1B, one end of the resistor R9, and one end of the variable resistor. The other end of the resistor R9 is grounded. The other end of the variable resistor is respectively connected to the collector of the transistor Q2, one end of the capacitor C3, one end of the capacitor EC2, the IN+ pin of the first detection chip U6, the IN- pin of the second detection chip U4, one end of the resistor R18, one end of the resistor R19, the emitter of the transistor Q5, the emitter of the transistor Q4, and one end of the resistor R17. The other end of the resistor R18 and the other end of the resistor R19 are connected to the collector of the transistor Q2, one end of the capacitor C3, one end of the capacitor EC2, the IN+ pin of the first detection chip U6, the IN- pin of the second detection chip U4, one end of the resistor R18, one end of the resistor R19, the emitter of the transistor Q5, the emitter of the transistor Q4, and one end of the resistor R17. They are all connected to the IN- pin of the first detection chip U6, the IN+ pin of the second detection chip U4, and the first pin of the detection interface, and the second pin of the detection interface, the other end of the capacitor C3, the other end of the capacitor EC1, and the other end of the capacitor EC2 are all grounded; the positive input port of the operational amplifier U1A is respectively connected to one end of the resistor R5, one end of the resistor R6, and one end of the capacitor C2, the other end of the capacitor R6 and the other end of the capacitor C2 are both grounded, the other end of the resistor R5 is respectively connected to one end of the resistor R4 and the positive input port of the operational amplifier U1B, the other end of the resistor R4 is respectively connected to one end of the resistor R40, one end of the resistor R1, one end of the voltage stabilizing source U2, and one end of the capacitor C13, and the stabilizing The other end of the voltage source U2 and the other end of the capacitor C13 are both grounded, and the other end of the resistor R1 is connected to the 5V voltage stabilization interface; the positive power supply port of the operational amplifier U1A is respectively connected to the 5V voltage stabilization interface and one end of the capacitor C1, the emitter of the transistor Q2 is respectively connected to the 12V voltage interface, one end of the capacitor EC1, and one end of the resistor R14, the other end of the capacitor EC1, the other end of the capacitor C1, and the negative power supply port of the operational amplifier U1A are all grounded; the output port of the operational amplifier U1A is respectively connected to the collector of the transistor Q6, the anode of the indicator light LED1, and one end of the resistor R11, the cathode of the indicator light LED1 is connected to one end of the resistor R26, and the other end of the resistor R26 is connected ground; the other end of the resistor R11 is respectively connected to one end of the resistor R12 and the base of the transistor Q1, the emitter of the transistor Q1 and the other end of the resistor R12 are both grounded, the collector of the transistor Q1 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to the other end of the resistor R14 and the base of the transistor Q2; the positive power supply port of the operational amplifier U1B is connected to the 5V voltage stabilizing interface, the negative power supply port of the operational amplifier U1B is grounded, the output port of the operational amplifier U1B is respectively connected to the collector of the transistor Q7, the anode of the indicator light LED3, and one end of the resistor R7, the cathode of the indicator light LED3 is connected to one end of the resistor R34, and the other end of the resistor R34 is grounded;The other end of the resistor R7 is connected to one end of the resistor R8 and the base of the transistor Q3 respectively. The emitter of the transistor Q3 and the other end of the resistor R8 are grounded. The collector of the transistor Q3 is connected to one end of the resistor R20. The other end of the resistor R20 is connected to the other end of the resistor R17, the base of the transistor Q4 and the base of the transistor Q5 respectively. The collector of the transistor Q4 and the collector of the transistor Q5 are grounded. ;

[0042] The transistor Q2, the transistor Q4 and the transistor Q5 are integrated on the same heat sink and are directly cooled by a fan connected to a fan connector.

[0043] The analog circuit has the following beneficial effects:

[0044] 1. The circuit components used in the simulation circuit of the present invention are all conventional materials, which are easy to purchase and inexpensive, effectively reducing the production cost of the lithium battery charging and discharging simulation circuit;

[0045] 2. The simulation circuit in the present invention utilizes the characteristics of the operational amplifier comparator to simulate the discharge and charge functions of the lithium battery; when verifying the charge, it utilizes the characteristics of the transistor in the amplification region to make the current passing through larger and wider, and ensure the accuracy of the charging current value; it truly simulates the charging and discharging performance of the lithium battery, greatly shortens the test time of the control board, improves the production efficiency of the control board, and enables it to realize industrial production operations;

[0046] 3. The energy source of the simulated lithium battery in the present invention is a switching power supply circuit module, which can be directly connected to the 220V mains for use, without the need to specifically find a 12V DC power supply, and the switching power supply circuit module itself also has over-temperature and over-voltage protection functions. Once the circuit function is abnormal, the switching power supply circuit module will quickly enter the protection state, and return to the normal state after the abnormality is resolved;

[0047] 4. The analog circuit in the present invention uses a special current detection chip for protection during the charging and discharging process. Once an overcurrent occurs, the output can be quickly disconnected to ensure that the safety of products such as the control board is not affected. At the same time, the switching power supply circuit module in the analog circuit also has an overcurrent protection function, which effectively realizes double overcurrent protection during the test process and further improves the safety of the product.

Claims

1. A simple circuit simulating lithium battery function, characterized in that: The simple simulated lithium battery functional circuit includes a switching power supply circuit module, a power supply voltage stabilizing circuit module, a fan power supply circuit module, an overcurrent detection protection circuit module, and a simulated lithium battery charging and discharging circuit module; the switching power supply circuit module is respectively connected to the power supply voltage stabilizing circuit module and the fan power supply circuit module and provides a 12V voltage to the power supply voltage stabilizing circuit module and the fan power supply circuit module; the power supply voltage stabilizing circuit module is respectively connected to the overcurrent detection protection circuit module and the simulated lithium battery charging and discharging circuit module and provides a 5V voltage to the overcurrent detection protection circuit module and the simulated lithium battery charging and discharging circuit module; the fan power supply circuit module is connected to the fan and dissipates heat for the heat sink integrated on the simulated lithium battery charging and discharging circuit module through the fan; the overcurrent detection protection circuit module is connected to the simulated lithium battery charging and discharging circuit module and realizes the charging overcurrent protection effect.

2. The simple lithium battery simulation function circuit as claimed in claim 1, characterized in that: The switching power supply circuit module includes a rectifier BD1 and a switching power supply chip U3. The first pin of the rectifier BD1 is connected to one end of the capacitor CX1 and the live wire through the inductor LF1. The second pin of the rectifier BD1 is connected to the other end of the capacitor CX1 and the neutral wire through the inductor LF1. The third pin of the rectifier BD1 is respectively connected to one end of the capacitor EC7, one end of the resistor R25, one end of the capacitor C10, and one end of the transformer coil TR1A. The fourth pin of the rectifier BD1 and the other end of the capacitor EC7 are both grounded. The other end of the resistor R25 and the other end of the capacitor C10 are both connected to one end of the resistor R24. The other end of the resistor R24 ​​is connected to the cathode of the diode D1. The anode of the diode D1 and the other end of the transformer coil TR1A are both connected to the SW pin of the switching power supply chip U3. The VDD pin of the switching power supply chip U3 is respectively connected to one end of the capacitor C12, one end of the capacitor EC8, and one end of the resistor R29. The other end of the resistor R29 is connected to one end of the diode D3. The other end of the diode D3 is connected to the cathode of the diode D1. The anode of the diode D1 and the other end of the transformer coil TR1A are both connected to the SW pin of the switching power supply chip U3. The other end of the resistor R30 is connected to the FB pin of the switching power chip U3, one end of the resistor R31, and one end of the resistor R32, respectively. The CS pin of the switching power chip U3 is connected to one end of the resistor R33 and one end of the resistor R42, respectively. The other end of the resistor R31, the other end of the resistor R32, and the other end of the resistor R33 are connected to the FB pin of the switching power chip U3, respectively. One end of the transformer coil TR1C is respectively connected to one end of the resistor R28 and the anode of the diode D2, the other end of the resistor R28 is connected to one end of the capacitor C11, the other end of the capacitor C11 and the cathode of the diode D2 are connected to one end of the capacitor EC9, the 12V voltage interface, and one end of the resistor R27, the other end of the transformer coil TR1C, the other end of the capacitor EC9, and the other end of the resistor R27 are all grounded.

3. The simple lithium battery simulation function circuit as claimed in claim 2, characterized in that: The power supply voltage stabilizing circuit module includes a transistor Q8, the collector of the transistor Q8, one end of the resistor R35, one end of the capacitor EC3, and one end of the capacitor C5 are all connected to the 12V voltage interface, the other end of the resistor R35 and the base of the transistor Q8 are all connected to the cathode of the voltage stabilizing diode, the emitter of the transistor Q8 and one end of the capacitor EC4 are all connected to the 5V voltage stabilizing interface, and the anode of the voltage stabilizing diode, the other end of the capacitor EC3, the other end of the capacitor C5, and the other end of the capacitor EC4 are all grounded.

4. The simple lithium battery simulation function circuit as claimed in claim 3, characterized in that: The fan power supply circuit module includes a step-down chip U5, the VIN pin of the step-down chip U5 is respectively connected to the 12V voltage interface, one end of the capacitor EC5, one end of the resistor R3, and one end of the capacitor C7, the other end of the resistor R3 is connected to the EN pin of the step-down chip U5, and the other end of the capacitor EC5 and the other end of the capacitor C7 are both grounded; the SW pin of the step-down chip U5 is respectively connected to one end of the capacitor C8 and one end of the inductor L1, the other end of the capacitor C8 is connected to the BST pin of the step-down chip U5, the other end of the inductor L1 is respectively connected to one end of the resistor R21, the VCC terminal, one end of the capacitor EC6, and the first pin of the fan connector, the other end of the resistor R21 and the FB pin of the step-down chip U5 are both connected to one end of the resistor R22, the other end of the resistor R22, the other end of the capacitor EC6, the second pin of the fan connector, and the GND pin of the step-down chip U5 are all grounded.

5. The simple lithium battery simulation function circuit as claimed in claim 4, characterized in that: The overcurrent detection protection circuit module includes a first detection chip U6, a second detection chip U4, an operational amplifier U7A, and an operational amplifier U7B; the V+ pin of the first detection chip U6 and one end of the capacitor C9 are connected to the 5V voltage stabilization interface, the other end of the capacitor C9, the REF pin of the first detection chip U6, and the GND pin of the first detection chip U6 are grounded, the OUT pin of the first detection chip U6 is connected to the positive input port of the operational amplifier U7A, and the IN- pin and IN+ pin of the first detection chip U6 are connected to the analog lithium battery charging and discharging circuit module The second detection chip U4 and one end of the capacitor C15 are connected to the 5V voltage regulator interface, the other end of the capacitor C15, the REF pin of the second detection chip U4, and the GND pin of the second detection chip U4 are grounded, the OUT pin of the second detection chip U4 is connected to the positive input port of the operational amplifier U7B, and the IN- pin and IN+ pin of the second detection chip U4 are connected to the analog lithium battery charging and discharging circuit module; the negative input port of the operational amplifier U7A is respectively connected to the negative input port of the operational amplifier U7B, the resistor One end of R40 and one end of resistor R41 are connected, the other end of resistor R40 is connected to the simulated lithium battery charging and discharging circuit module, and the other end of resistor R41 is grounded; the positive power supply port of the operational amplifier U7A is respectively connected to the 5V voltage stabilizing interface and one end of capacitor C14, and the other end of capacitor C14 and the negative power supply port of the operational amplifier U7A are both grounded; the output port of the operational amplifier U7A is connected to one end of resistor R39, and the other end of resistor R39 is respectively connected to one end of resistor R38 and the base of transistor Q6, and the other end of resistor R38, The emitter of the transistor Q6 is grounded, and the collector of the transistor Q6 is connected to the simulated lithium battery charging and discharging circuit module; the positive power supply port of the operational amplifier U7B is connected to the 5V voltage regulator interface, and the negative power supply port of the operational amplifier U7B is grounded; the output port of the operational amplifier U7B is connected to one end of the resistor R36, and the other end of the resistor R36 is respectively connected to one end of the resistor R37 and the base of the transistor Q7, the other end of the resistor R37 and the emitter of the transistor Q7 are grounded, and the collector of the transistor Q7 is connected to the simulated lithium battery charging and discharging circuit module.

6. The simple lithium battery simulation function circuit as claimed in claim 5, characterized in that: The simulated lithium battery charging and discharging circuit module includes an operational amplifier U1A and an operational amplifier U1B. The negative input port of the operational amplifier U1A is respectively connected to the positive input port of the operational amplifier U1B, one end of a resistor R9, and one end of a variable resistor. The other end of the resistor R9 is grounded. The other end of the variable resistor is respectively connected to the collector of a transistor Q2, one end of a capacitor C3, one end of a capacitor EC2, an IN+ pin of a first detection chip U6, an IN- pin of a second detection chip U4, one end of a resistor R18, one end of a resistor R19, an emitter of a transistor Q5, an emitter of a transistor Q4, and one end of a resistor R17. The other ends of the resistor R18 and R19 are both connected to the first The IN- pin of the detection chip U6, the IN+ pin of the second detection chip U4, and the first pin of the detection interface are connected, and the second pin of the detection interface, the other end of the capacitor C3, the other end of the capacitor EC1, and the other end of the capacitor EC2 are all grounded; the positive input port of the operational amplifier U1A is respectively connected to one end of the resistor R5, one end of the resistor R6, and one end of the capacitor C2, and the other end of the capacitor R6 and the other end of the capacitor C2 are both grounded, the other end of the resistor R5 is respectively connected to one end of the resistor R4 and the positive input port of the operational amplifier U1B, and the other end of the resistor R4 is respectively connected to one end of the resistor R40, one end of the resistor R1, one end of the voltage stabilizing source U2, and one end of the capacitor C13, and the voltage stabilizing source The other end of U2 and the other end of capacitor C13 are both grounded, and the other end of resistor R1 is connected to the 5V voltage stabilizing interface; the positive power supply port of the operational amplifier U1A is respectively connected to the 5V voltage stabilizing interface and one end of capacitor C1, the emitter of transistor Q2 is respectively connected to the 12V voltage interface, one end of capacitor EC1, and one end of resistor R14, the other end of capacitor EC1, the other end of capacitor C1, and the negative power supply port of the operational amplifier U1A are all grounded; the output port of the operational amplifier U1A is respectively connected to the collector of transistor Q6, the anode of indicator light LED1, and one end of resistor R11, the cathode of indicator light LED1 is connected to one end of resistor R26, and the other end of resistor R26 is grounded ; The other end of the resistor R11 is respectively connected to one end of the resistor R12 and the base of the transistor Q1, the emitter of the transistor Q1 and the other end of the resistor R12 are grounded, the collector of the transistor Q1 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to the other end of the resistor R14 and the base of the transistor Q2; the positive power supply port of the operational amplifier U1B is connected to the 5V voltage stabilizing interface, the negative power supply port of the operational amplifier U1B is grounded, the output port of the operational amplifier U1B is respectively connected to the collector of the transistor Q7, the anode of the indicator LED3, and one end of the resistor R7, the cathode of the indicator LED3 is connected to one end of the resistor R34, and the other end of the resistor R34 is grounded;The other end of the resistor R7 is connected to one end of the resistor R8 and the base of the transistor Q3 respectively. The emitter of the transistor Q3 and the other end of the resistor R8 are grounded. The collector of the transistor Q3 is connected to one end of the resistor R20. The other end of the resistor R20 is connected to the other end of the resistor R17, the base of the transistor Q4 and the base of the transistor Q5 respectively. The collector of the transistor Q4 and the collector of the transistor Q5 are grounded. ; 7. The simple lithium battery simulation function circuit as claimed in claim 6, characterized in that: The transistor Q2, the transistor Q4 and the transistor Q5 are integrated on the same heat sink and are directly cooled by a fan connected to a fan connector.

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