Lithium battery pack charging and discharging protection circuit of teaching demonstration robot

Abstract

The utility model discloses a lithium battery pack charging and discharging protection circuit of a teaching demonstration robot. The lithium battery pack charging and discharging protection circuit comprises a chip S-8204B, an NMOS tube Q3 and an NMOS tube Q4, and positive electrodes of lithium batteries are respectively connected with one of VC1 to VC4 pins of the chip S-8204B; the COP pin of the chip S-8204B is connected with the G pole of the Q3, a resistor R11 is connected in series between the DOP pin of the chip S-8204B and the G pole of the Q4, and a resistor R13 is connected in series between the VINI pin of the chip S-8204B and the D pole of the Q4; the S pole of the Q3 is connected with the negative connection terminal of the lithium battery pack, the D pole of the Q3 is connected with the S pole of the Q4, and a resistor R15 is connected in series between the negative pole of the lithium batteries connected in series and the D pole of the Q4; a CDT pin, a CCT pin and a CIT pin of the chip S-8204B are respectively connected with a delay capacitor C6, a delay capacitor C1 and a delay capacitor C7 and then are connected with negative electrodes of the lithium batteries which are connected in series, an SEL pin of the chip S-8204B is connected with a VDD pin of the chip S-8204B and positive electrodes of the lithium batteries which are connected in series, the positive electrodes of the lithium batteries which are connected in series are connected with a positive connection terminal of the lithium battery pack, a VSS pin of the chip S-8204B is connected with the negative electrodes of the lithium batteries which are connected in series, and the positive connection terminal of the lithium battery pack is connected with a positive connection terminal of the lithium battery pack. The utility model has the advantages of accurate data during working, simple circuit and low cost.

Description

Technical Field

[0001] The utility model relates to the field of lithium ion batteries, and more specifically to a lithium battery pack charging and discharging protection circuit for a teaching demonstration robot. Background Art

[0002] Lithium-ion batteries are commonly used in teaching demonstration robots and other equipment. Lithium-ion batteries are strictly prohibited from overcharging, over-discharging and short-circuiting during use, otherwise it will shorten the battery life or cause accidents such as fire and explosion, which is obviously very unsafe. Therefore, it is necessary to provide a lithium battery charging and discharging protection circuit to solve the above technical problems, while taking into account the accuracy and cost of the circuit. Utility Model Content

[0003] The utility model aims to provide a lithium battery pack charging and discharging protection circuit for a teaching demonstration robot with high accuracy and low cost.

[0004] The utility model discloses a lithium battery pack charge and discharge protection circuit for a teaching demonstration robot, wherein the lithium battery pack comprises a plurality of lithium batteries connected in series, a chip S-8204B, an NMOS tube Q3, and an NMOS tube Q4;

[0005] The positive poles of the lithium batteries are each connected to one of the VC1 to VC4 pins of the chip S-8204B; the COP pin of the chip S-8204B is connected to the G pole of the NMOS tube Q3, the DOP pin of the chip S-8204B and the G pole of the NMOS tube Q4 are connected in series with a resistor R11, and the VINI pin of the chip S-8204B and the D pole of the NMOS tube Q4 are connected in series with a resistor R13; the S pole of the NMOS tube Q3 is connected to the negative connection terminal of the lithium battery pack, and the D pole of the NMOS tube Q3 is connected to the S pole of the NMOS tube Q4. A resistor R15 is connected in series between the negative electrode of the series-connected lithium batteries and the D electrode of the NMOS tube Q4; the CDT, CCT, and CIT pins of the chip S-8204B are respectively connected to the delay capacitors C6, C1, and C7 and then connected to the negative electrode of the series-connected lithium batteries; the SEL pin of the chip S-8204B is connected to the VDD pin of the chip S-8204B and the positive electrode of the series-connected lithium batteries; the positive electrode of the series-connected lithium batteries is connected to the positive connection terminal of the lithium battery pack; and the VSS pin of the chip S-8204B is connected to the negative electrode of the series-connected lithium batteries.

[0006] Preferably, in the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the utility model, a bias resistor R14 with a value of 0.8 MΩ is connected between the G pole and the S pole of the NMOS tube Q3.

[0007] Preferably, in the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the present invention, a filter resistor is connected in series between the positive electrode of each lithium battery and one of the VC1 to VC4 pins of the chip S-8204B to which it is connected, and the end of the filter resistor close to the chip S-8204B is respectively connected in series with a filter capacitor and then connected to the negative electrode of the series-connected lithium batteries.

[0008] Preferably, in the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the present invention, the SEL pin of the chip S-8204B is connected to one end of a filter resistor R10, and the other end of the filter resistor R10 is connected to the VDD pin of the chip S-8204B on the one hand, and another filter resistor R5 is connected in series with the positive electrode of the lithium battery in series on the other hand, and a filter capacitor C8 is connected between the VDD pin of the chip S-8204B and the negative electrode of the lithium battery in series.

[0009] Preferably, the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the utility model also includes an over-temperature protection connection terminal and an NTC resistor, one end of the NTC resistor is connected to the over-temperature protection connection terminal, and the other end is connected to the negative connection terminal of the lithium battery pack.

[0010] Preferably, in the lithium battery pack charging and discharging protection circuit of the teaching demonstration robot of the utility model, it also includes a PMOS tube Q1 and an NMOS tube Q2. The S pole of the PMOS tube Q1 is connected to the CTLC pin and the CTLD pin of the chip S-8204B through resistors R2 and R3 respectively. A resistor R1 is connected in series between the D poles of the PMOS tube Q1 and the NMOS tube Q2. The D pole of the NMOS tube Q2 is connected to the VMP pin of the chip S-8204B. The S pole of the NMOS tube Q2 is connected to the negative pole of the lithium battery after the series connection. After the G poles of the PMOS tube Q1 and the NMOS tube Q2 are connected, one end of a resistor R12 is connected in series on the one hand, and the cathode of a diode D1 is connected on the other hand. The other end of the resistor R12 is connected to the S pole of the NMOS tube Q3, and the anode of the diode D1 is connected to the S pole of the NMOS tube Q2.

[0011] Preferably, in the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the present invention, the models of NMOS tube Q2, NMOS tube Q3 and NMOS tube Q4 are IRF630, and the model of the diode is IN4742.

[0012] Preferably, in the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the present utility model, the series resistor R11 is 5.6KΩ, the series resistor R13 is 4.7KΩ, the series resistor R7 is .2KΩ, and the capacitors C6, C1, and C7 are 0.1μF.

[0013] Preferably, in the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the utility model, the filter resistor is 1KΩ, and the filter capacitor is 50nF.

[0014] Preferably, in the lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the utility model, a resistor R4 of 21 MΩ is connected between the positive connection terminal and the negative connection terminal.

[0015] The lithium battery pack charging and discharging protection circuit of the teaching demonstration robot of the utility model is used for battery charging and discharging protection of the teaching demonstration robot, etc., and can realize overcharge protection, over-discharge protection, overcurrent protection and overheat protection. The load short-circuit protection adds a protection circuit in the lithium battery to control the voltage and current within a normal range to extend the battery life, and even avoid accidents such as battery fire or explosion. The utility model has accurate data when working, simple circuit and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0017] Figure 1 The utility model is a schematic diagram of an embodiment of a lithium battery pack charge and discharge protection circuit of a teaching demonstration robot. DETAILED DESCRIPTION

[0018] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0019] refer to Figure 1 This embodiment discloses a lithium battery pack charge and discharge protection circuit of a teaching demonstration robot, wherein the lithium battery pack comprises four lithium batteries V1, V2, V3, and V4 connected in series, and the lithium batteries are 18650 lithium batteries. The lithium battery pack charge and discharge protection circuit of the teaching demonstration robot comprises a chip S-8204B, a PMOS tube Q1, an NMOS tube Q2, an NMOS tube Q3, and an NMOS tube Q4, wherein the model of the PMOS tube Q1 is IRF9230, and the model of the NMOS tube Q2, the NMOS tube Q3, and the NMOS tube Q4 is IRF630.

[0020] The positive electrodes of the four lithium batteries V1, V2, V3, and V4 are connected to the VC1 to VC4 pins of the chip S-8204B in sequence, and a filter resistor R6, R7, R8, and R9 are respectively connected in series between the positive electrodes of the lithium batteries V1, V2, V3, and V4 and the VC1 to VC4 pins of the chip S-8204B. The filter resistors R6, R7, R8, and R9 are respectively connected in series with a filter capacitor C5, C4, C3, and C2 at the end close to the chip S-8204B, and are then respectively connected to the negative electrodes of the lithium batteries connected in series, that is, the negative electrode of the lithium battery V4. The filter resistors R6, R7, R8, and R9 and their corresponding filter capacitors C5, C4, C3, and C2 respectively form a low-pass filter to suppress high-frequency noise. In this embodiment, R6=R7=R8=R9=1KΩ, C5=C4=C3=C2=50nF.

[0021] The COP pin of the chip S-8204B is connected to the G pole of the NMOS tube Q3. A resistor R11 is connected in series between the DOP pin of the chip S-8204B and the G pole of the NMOS tube Q4. R11 = 5.6KΩ. A resistor R13 is connected in series between the VINI pin of the chip S-8204B and the D pole of the NMOS tube Q4. R13 = 4.7KΩ. The S pole of the NMOS tube Q3 is connected to the negative connection terminal BAT- of the lithium battery pack. The D pole of the NMOS tube Q3 is connected to the N A resistor R15 is connected in series between the S pole of the MOS tube Q4, the negative pole of the lithium battery V4 and the D pole of the NMOS tube Q4, R15=7.2KΩ, a bias resistor R14 with a value of 0.8MΩ is connected between the G pole and the S pole of the NMOS tube Q3, and the bias resistor R14 provides a bias voltage for the NMOS tube Q3. The resistor R11 is used to suppress high-frequency oscillations, the resistor R13 is used to convert the low-voltage signal into a current signal for current sampling, and the resistor R15 is used for current limiting protection.

[0022] The CDT, CCT, and CIT pins of the chip S-8204B are connected to the delay capacitors C6, C1, and C7 respectively, and then connected to the negative electrode of the lithium battery V4. The SEL pin of the chip S-8204B is connected to the VDD pin of the chip S-8204B and the positive electrode of the lithium batteries connected in series. The positive electrode of the lithium batteries connected in series is the positive electrode of the lithium battery V1. The positive electrode of the lithium battery V1 is connected to the positive connection terminal BAT+ of the lithium battery pack. The VSS pin of the chip S-8204B is connected to the negative electrode of the lithium battery V4. Preferably, the SEL pin of the chip S-8204B is connected to one end of a filter resistor R10, and the other end of the filter resistor R10 is connected to the VDD pin of the chip S-8204B on one hand, and another filter resistor R5 is connected in series with the positive electrode of the lithium battery V1 on the other hand, and a filter capacitor C8 is connected between the VDD pin of the chip S-8204B and the negative electrode of the lithium battery V4, wherein C6=C1=C7=0.1μF, R10=2KΩ, R5=0.05KΩ, C8=1μF. C6, C1, and C7 are delay capacitors, and the filter resistor R10, the filter capacitor C8, and the filter resistor R5 together constitute an RCR filter circuit.

[0023] The S pole of the PMOS tube Q1 is connected to the CTLC pin and the CTLD pin of the chip S-8204B through the resistors R2 and R3 respectively. A resistor R1 is connected in series between the D poles of the PMOS tube Q1 and the NMOS tube Q2. The D pole of the NMOS tube Q2 is connected to the VMP pin of the chip S-8204B. The S pole of the NMOS tube Q2 is connected to the negative pole of the lithium battery after being connected in series. After the G poles of the PMOS tube Q1 and the NMOS tube Q2 are connected, one end of a resistor R12 is connected in series on the one hand, and the cathode of a diode D1 is connected on the other hand. The model of the diode D1 is IN4742. The other end of the resistor R12 is connected to the S pole of the NMOS tube Q3, and the anode of the diode D1 is connected to the S pole of the NMOS tube Q2. R2=R3=3.8KΩ, R1=6.5KΩ, R12=1.2MΩ, R2=R3 is the input resistor, R1 plays a current limiting role to prevent the circuit current from being too large after the PMOS tube Q1 and the NMOS tube Q2 are both turned on, and R12 is the G-pole resistor of the PMOS tube Q1 and the NMOS tube Q2, which is used for current regulation.

[0024] The lithium battery pack charge and discharge protection circuit of the teaching demonstration robot of the utility model also includes an over-temperature protection connection terminal and an NTC resistor, one end of the NTC resistor is connected to the over-temperature protection connection terminal TH, and the other end is connected to the negative connection terminal BAT- of the lithium battery pack, and the maximum resistance of the NTC resistor is 10KΩ. A 21MΩ resistor R4 is connected between the positive connection terminal and the negative connection terminal to serve as the input impedance of the battery pack.

[0025] Working principle of the utility model: the circuit overcharge detection voltage is 4.2V, the overcharge release voltage is 4.1V. When any battery voltage is higher than 4.1V, the COP terminal will become high impedance, the MOS tube Q3 will be turned off, and charging will stop. The circuit over-discharge detection voltage is 2.7V, the over-discharge release voltage is 2.9V. When any battery voltage is lower than 2.7V, the voltage of the DOP terminal becomes the VSS potential, the MOS tube Q4 will be turned off, and discharging will stop. The circuit over-current detection voltage is 0.25V. When the VINI terminal voltage is equal to or exceeds 0.25V, the DOP terminal becomes the VSS potential, the MOS tube Q4 will be turned off, and discharging will stop. The load short-circuit detection voltage is 1V. When the VINI terminal voltage is equal to or exceeds 1V, the MOS tube Q4 will be turned off, and discharging will stop. The TH port is the over-temperature protection port, which is connected to the CPU of the robot. An NTC resistor is connected to the TH port and the BAT- port. The resistor is installed close to the lithium battery. The CPU detects the NTC resistance value. When the resistance value drops to 1.5kΩ, the battery stops outputting. In the entire circuit, the battery charging is input by the ports BAT+ and BAT-, and the discharge is output by the ports BAT+ and BAT-. The IC will always monitor the voltage between VDD and VSS. If overcharging or over-discharging occurs, then COP and DOP will control the on and off of MOS tubes Q3 and Q4. VMP can be used to determine whether it is charging or discharging by the detected voltage. Q1 is a PMOS tube and Q2 is an NMOS tube. When the G pole connected to them is at a high level, Q2 is turned on and Q1 is turned off. At this time, the VMP pin is connected to VSS. When the G pole is at a low level, Q1 is turned on and Q2 is turned off. At this time, the VMP pin is connected to VDD.

[0026] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A lithium battery pack charge and discharge protection circuit for a teaching demonstration robot, wherein the lithium battery pack comprises multiple lithium batteries connected in series, characterized in that: It includes chip S-8204B, NMOS tube Q3, and NMOS tube Q4; The positive poles of the lithium batteries are each connected to one of the VC1 to VC4 pins of the chip S-8204B; the COP pin of the chip S-8204B is connected to the G pole of the NMOS tube Q3, the DOP pin of the chip S-8204B and the G pole of the NMOS tube Q4 are connected in series with a resistor R11, and the VINI pin of the chip S-8204B and the D pole of the NMOS tube Q4 are connected in series with a resistor R13; the S pole of the NMOS tube Q3 is connected to the negative connection terminal of the lithium battery pack, and the D pole of the NMOS tube Q3 is connected to the S pole of the NMOS tube Q4. A resistor R15 is connected in series between the negative electrode of the series-connected lithium batteries and the D electrode of the NMOS tube Q4; the CDT, CCT, and CIT pins of the chip S-8204B are respectively connected to the delay capacitors C6, C1, and C7 and then connected to the negative electrode of the series-connected lithium batteries; the SEL pin of the chip S-8204B is connected to the VDD pin of the chip S-8204B and the positive electrode of the series-connected lithium batteries; the positive electrode of the series-connected lithium batteries is connected to the positive connection terminal of the lithium battery pack; and the VSS pin of the chip S-8204B is connected to the negative electrode of the series-connected lithium batteries.

2. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 1, characterized in that: A bias resistor R14 with a value of 0.8 MΩ is connected between the G pole and the S pole of the NMOS tube Q3.

3. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 1, characterized in that: A filter resistor is connected in series between the positive electrode of each lithium battery and one of the VC1 to VC4 pins of the chip S-8204B to which it is connected. A filter capacitor is connected in series to the end of the filter resistor close to the chip S-8204B and then connected to the negative electrode of the series-connected lithium batteries.

4. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 1, characterized in that: The SEL pin of the chip S-8204B is connected to one end of a filter resistor R10, and the other end of the filter resistor R10 is connected to the VDD pin of the chip S-8204B on the one hand, and another filter resistor R5 is connected in series between the positive electrode of the lithium battery in series on the other hand, and a filter capacitor C8 is connected between the VDD pin of the chip S-8204B and the negative electrode of the lithium battery in series.

5. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 1, characterized in that: It also includes an over-temperature protection connection terminal and an NTC resistor, one end of the NTC resistor is connected to the over-temperature protection connection terminal, and the other end is connected to the negative connection terminal of the lithium battery pack.

6. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 1, characterized in that: It also includes a PMOS tube Q1 and an NMOS tube Q2. The S pole of the PMOS tube Q1 is connected to the CTLC pin and the CTLD pin of the chip S-8204B through resistors R2 and R3 respectively. A resistor R1 is connected in series between the D poles of the PMOS tube Q1 and the NMOS tube Q2. The D pole of the NMOS tube Q2 is connected to the VMP pin of the chip S-8204B. The S pole of the NMOS tube Q2 is connected to the negative pole of the lithium battery after being connected in series. After the G poles of the PMOS tube Q1 and the NMOS tube Q2 are connected, one end of a resistor R12 is connected in series on the one hand, and the cathode of a diode D1 is connected on the other hand. The other end of the resistor R12 is connected to the S pole of the NMOS tube Q3, and the anode of the diode D1 is connected to the S pole of the NMOS tube Q2.

7. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 5, characterized in that: The model of the PMOS tube Q1 is IRF9230, the model of the NMOS tube Q2, NMOS tube Q3, and NMOS tube Q4 are IRF630, and the model of the diode is IN4742.

8. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 1, characterized in that: The series resistor R11 has a value of 5.6KΩ, the series resistor R13 has a value of 4.7KΩ, the series resistor R7 has a value of .2KΩ, and the capacitors C6, C1, and C7 have a value of 0.1μF.

9. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 3, characterized in that: The filter resistor is 1KΩ, and the filter capacitor is 50nF.

10. The lithium battery pack charge and discharge protection circuit of a teaching demonstration robot according to claim 3, characterized in that: A resistor R4 of 21 MΩ is connected between the positive connection terminal and the negative connection terminal.

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