Low-cost high-precision battery electric quantity detection circuit

Abstract

The utility model discloses a low-cost high-precision battery electric quantity detection circuit, comprising a charging source access module which is respectively connected with a positive electrode and a negative electrode of a battery, and a current sampling resistor is connected in series on a connection circuit of the charging source access module and the negative electrode of the battery; the current amplification module is connected with the current sampling resistor; the data acquisition and processing module is connected with the charging source access module, the current amplification module and the battery, and the data acquisition and processing module acquires the current sampling value and the voltage value of the battery and determines the electric quantity value of the battery according to the current sampling value and the voltage value of the battery; and the electric quantity display module is connected with the data acquisition and processing module. According to the technical scheme, the current sampling value on the current sampling resistor is firstly amplified through the current amplification module, so that the data acquisition and processing module port can obtain the tiny current sampling value, the detection precision is improved, in addition, an electric quantity detection chip is not needed, and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic product technical field especially, a kind of low-cost high-precision battery power detection circuit. BACKGROUND

[0002] In some electronic products of battery, the power of battery when discharging and the power when charging need to be detected, to achieve timely charging.

[0003] At present, when detecting the power of battery, the power of battery when charging or discharging is detected using power detection chip, the battery power detection circuit using power detection chip can detect the power of battery when charging or discharging, but the precision is low and the cost is high.

[0004] Therefore, prior art remains to be improved and developed. INVENTION CONTENTS

[0005] In view of the above deficiencies of prior art, the purpose of the utility model is to provide a kind of low-cost high-precision battery power detection circuit, to solve the problem of low precision and high cost of battery power detection circuit using power detection chip in prior art.

[0006] The utility model provides a kind of low-cost high-precision battery power detection circuit, comprising:

[0007] Charging source access module is connected with the positive pole and the negative pole of battery respectively, current sampling resistance is connected in series on the connecting road of the negative pole of the charging source access module and the battery, and the charging source access module is used to access charging source;

[0008] Current amplification module is connected with the current sampling resistance, and the current amplification module is used to amplify the sampling current on the current sampling resistance and output current sampling value;

[0009] Data acquisition and processing module is connected with the charging source access module, the current amplification module and battery, and the data acquisition and processing module is used to obtain the current sampling value and the voltage value of the battery, and determine the power value of the battery according to the current sampling value and the voltage value of the battery;The data acquisition and processing module is also used to control the charging source access module according to the voltage value of the battery when the charging source access module accesses charging source, so that charging source charges the battery;

[0010] Power display module is connected with the data acquisition and processing module, and the power display module is used to display the power value of the battery.

[0011] The further setting of the utility model further comprises:

[0012] A first voltage stabilizing module having a voltage input end and a voltage output end, the voltage input end of the first voltage stabilizing module being connected with the battery, and the voltage output end of the first voltage stabilizing module being connected with the data acquisition and processing module, the current amplification module and the power display module respectively.

[0013] The current amplification module further comprises a third capacitor, a fourth capacitor and a fifth capacitor.

[0014] One end of the first resistor is connected with one end of the current sampling resistor, and the other end of the first resistor is connected with the 5th pin of the first chip.

[0015] One end of the second resistor is connected with the other end of the current sampling resistor, and the other end of the second resistor is connected with the 4th pin of the first chip.

[0016] One end of the third resistor is connected with the 6th pin of the first chip, and the other end of the third resistor is connected with the data acquisition and processing module.

[0017] One end of the first capacitor is connected with the voltage output end of the first voltage stabilizing module and the 3rd pin of the first chip, and the other end of the first capacitor is connected with the 1st pin of the first chip and the data acquisition and processing module.

[0018] One end of the second capacitor is connected with the 5th pin of the first chip, and the other end of the second capacitor is connected with the 4th pin of the first chip.

[0019] The 2nd pin of the first chip is connected with the 1st pin of the first chip.

[0020] The current amplification module further comprises a third capacitor, a fourth capacitor and a fifth capacitor.

[0021] One end of the third capacitor is connected with the other end of the first resistor, and the other end of the third capacitor is grounded.

[0022] One end of the fourth capacitor is connected with the other end of the second resistor, and the other end of the fourth capacitor is grounded.

[0023] One end of the fifth capacitor is connected with the other end of the third resistor, and the other end of the fifth capacitor is grounded.

[0024] The data acquisition and processing module comprises:

[0025] A first switch unit.

[0026] The second chip is connected with the charging source access module through the second pin, the fifth pin and the seventeenth pin, the sixth pin and the fourteenth pin of the second chip are connected with the current amplification module, the fifteenth pin and the twentieth pin of the second chip are connected with the battery through the first switch unit, the seventh pin of the second chip is grounded, the tenth pin of the second chip is connected with the first voltage stabilizing module, the second chip is used for obtaining the current sampling value and the voltage value of the battery, and the battery capacity value is determined according to the current sampling value and the voltage value of the battery; the second chip is also used for controlling the charging source access module according to the voltage value of the battery when the charging source access module accesses the charging source, so that the charging source charges the battery, wherein the second chip obtains the voltage value of the battery when the first switch unit is in the closed state.

[0027] The first switch unit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a sixth capacitor, a first switch tube and a second switch tube.

[0028] One end of the fourth resistor is connected with the positive electrode of the battery, the other end of the fourth resistor is connected with one end of the fifth resistor, the other end of the fifth resistor is connected with the collector of the first switch tube, one end of the sixth resistor is connected with the base of the first switch tube, the other end of the sixth resistor is connected with the fifteenth pin of the second chip, one end of the seventh resistor is connected with the base of the first switch tube, the other end of the seventh resistor is connected with the emitter of the first switch tube, and the emitter of the first switch tube is grounded.

[0029] The source of the second switch tube is connected with the positive electrode of the battery, the gate of the second switch tube is connected with the other end of the fourth resistor, the drain of the second switch tube is connected with one end of the eighth resistor, the other end of the eighth resistor is connected with one end of the ninth resistor, the other end of the ninth resistor is grounded, and the other end of the eighth resistor is also connected with the twentieth pin of the second chip.

[0030] One end of the sixth capacitor is connected to the connection path of the other end of the eighth resistor and the twentieth pin of the second chip, and the other end of the sixth capacitor is grounded.

[0031] The charging source access module comprises:

[0032] The second switch unit is connected with the data acquisition and processing module.

[0033] The first interface unit is used for accessing the charging source, and the first interface unit is connected with the battery through the second switch unit.

[0034] The charging source access signal detection unit is connected with the first interface unit and the data acquisition and processing module, and is configured to output a first state signal, wherein the first state signal comprises a state of the first interface unit being connected with the charging source and a state of the first interface unit being disconnected with the charging source.

[0035] When the first state signal is the state of the first interface unit being connected with the charging source, the data acquisition and processing module is configured to control the second switch unit according to the voltage value of the battery, so that the charging source charges the battery.

[0036] The first interface unit comprises a tenth resistor, an eleventh resistor, a seventh capacitor and a first interface.

[0037] The first pin and the second pin of the first interface are short-circuited, the third pin of the first interface is connected with one end of the tenth resistor, the other end of the tenth resistor is grounded, the fourth pin of the first interface is connected with one end of the eleventh resistor, the other end of the eleventh resistor is grounded, the fifth pin of the first interface and the sixth pin of the first interface are grounded in common, one end of the seventh capacitor is connected with the first pin of the first interface, and the other end of the seventh capacitor is grounded.

[0038] The second switch unit comprises a first diode, a third switch tube, a fourth switch tube, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a fifteenth resistor.

[0039] The anode of the first diode is connected with the first pin of the first interface, the cathode of the first diode is connected with the source of the third switch tube, and the drain of the third switch tube is connected with the anode of the battery.

[0040] One end of the twelfth resistor is connected with the source of the third switch tube, the other end of the twelfth resistor is connected with the gate of the third switch tube, one end of the thirteenth resistor is connected with the other end of the twelfth resistor, the other end of the thirteenth resistor is connected with the collector of the fourth switch tube, the base of the fourth switch tube is connected with one end of the fourteenth resistor, and the emitter of the fourth switch tube is grounded.

[0041] The other end of the fourteenth resistor is connected with the data acquisition and processing module, one end of the fifteenth resistor is connected with one end of the fourteenth resistor, and the other end of the fifteenth resistor is connected with the emitter of the fourth switch tube.

[0042] The charging source access signal detection unit comprises a sixteenth resistor, a seventeenth resistor and an eighth capacitor.

[0043] One end of the sixteenth resistor is connected with one end of the seventh capacitor, the other end of the sixteenth resistor is connected with one end of the seventeenth resistor, the other end of the seventeenth resistor and the other end of the sixteenth resistor are connected with the data acquisition and processing module, one end of the eighth capacitor is connected with the other end of the sixteenth resistor, the other end of the eighth capacitor is connected with the other end of the seventeenth resistor.

[0044] The further setting of the utility model discloses, the voltage input end of first voltage stabilizing module is still connected with the 1st foot of first interface.

[0045] The further setting of the utility model discloses, the low -cost high accuracy battery electric quantity detection circuit still includes: temperature detection module, with the battery and data acquisition and processing module are connected, temperature detection module is used for gathering the temperature signal of battery and transmission to data acquisition and processing module.

[0046] The utility model discloses a low -cost high accuracy battery electric quantity detection circuit, in the low -cost high accuracy battery electric quantity detection circuit detects the battery electric quantity, through current amplification module amplifies the current on current sampling resistance, and the current transmission is obtained to data acquisition and processing module, and simultaneously, data acquisition and processing module still obtains the voltage value of battery, and data acquisition and processing module obtains the current value and the voltage value of battery after amplification, determines the electric quantity value of battery according to the current value and the voltage value of battery of obtaining amplification, to make electric quantity display module display the electric quantity value of battery, and when charging source access module accesses charging source, according to the electric quantity value of battery control charging source access module, to make charging source charge to battery. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will briefly introduce the drawing needed to be used in embodiment or prior art description, and obviously, the drawing in the following description is only some embodiments of the utility model, and for the ordinary person in the art, under the premise of not paying the creative labor, other drawings can also be obtained according to the structure shown in these drawings.

[0048] Figure 1 It is the principle block diagram of low -cost high accuracy battery electric quantity detection circuit in the utility model.

[0049] Figure 2is a first chip and peripheral device connection circuit diagram in one embodiment of the utility model.

[0050] Figure 3 is a charging source access module and first switch unit in one embodiment of the utility model.

[0051] Figure 4 is a second chip and peripheral device connection circuit diagram in one embodiment of the utility model.

[0052] Figure 5 is the circuit diagram of first voltage stabilizing module in one embodiment of the utility model.

[0053] Figure 6 is the circuit diagram of temperature detection module in one embodiment of the utility model.

[0054] Figure 7 is a fourth chip and peripheral device connection circuit diagram in one embodiment of the utility model.

[0055] Figure 8 is the connection diagram of liquid crystal display screen and second interface in one embodiment of the utility model.

[0056] Figure 9 is load driving circuit diagram in one embodiment of the utility model.

[0057] Figure 10 is the electric quantity detection chip and peripheral device connection circuit diagram of prior art application.

[0058] The marks in the drawing: 10, charging source access module;101, first interface unit;102, charging source access signal detection unit;103, second switch unit;20, current amplification module;30, battery;40, current sampling resistance;50, data acquisition and processing module;501, first switch unit;60, first voltage stabilizing module;70, electric quantity display module;80, temperature detection module. DETAILED DESCRIPTION

[0059] In order to have more clear understanding of the technical features, object and effect of the utility model, now the specific embodiment of the utility model is described in detail with reference to the drawing. In the following description, it is understood that the orientation or position relation of "front", "back", "upper", "lower", "left", "right", "vertical", "horizontal", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail" and the like indicated is based on the orientation or position relation shown in the drawing, constructs and operates in a particular orientation, and is only for the convenience of describing the technical scheme, and is not indicated that the indicated device or element must have a particular orientation, therefore, it must not be understood as the limitation of the utility model.

[0060] In some battery-powered electronic products, it is necessary to detect the battery's charge level during discharge and charging to ensure timely recharging. For example... Figure 10 The image shows a battery power detection circuit using a power detection chip, specifically the DS2788. Figure 10 In the disclosed battery power detection circuit, when the battery is charging, current flows from the positive terminal of the power supply ( Figure 10 When the PK+ input is used, the battery pack begins to charge. The current passes through the protection circuit and the detection resistor Rsns, and then returns to the negative terminal of the power supply. Figure 10 The battery charge detection circuit (using the PK pin) detects the voltage difference across resistor Rsns via the sns and vss pins of the power detection chip, and calculates the battery charge level during charging until fully charged. During discharge, current flows from the negative terminal of the power supply to the load and then from the load to the positive terminal. Similarly, the voltage difference across resistor Rsns is detected by the sns and vss pins of the power detection chip, and the battery charge level during discharge is calculated based on this difference until discharge ends. While this battery charge detection circuit using a power detection chip can detect the battery charge level during charging and discharging, it suffers from low accuracy and high cost.

[0061] Based on the problems mentioned above, such as Figure 1 As shown, this utility model provides a low-cost, high-precision battery power detection circuit, which may include a charging power access module 10, a current amplification module 20, a data acquisition and processing module 50, and a power display module 70.

[0062] The charging power access module 10 is connected to both the positive and negative terminals of the battery 30. A current sampling resistor 40 is connected in series between the charging power access module 10 and the negative terminal of the battery 30. The charging power access module 10 is used to connect to a charging power source. The current amplification module 20 is connected to the current sampling resistor 40. The current amplification module 20 is used to amplify the sampled current on the current sampling resistor 40 and output the current sampling value. The data acquisition and processing module 50 is connected to the charging power access module 10, the current amplification module 20, and the battery 30. The data acquisition and processing module 50 is used to acquire the current sampling value and the voltage value of the battery 30, and to determine the battery capacity value based on the current sampling value and the battery voltage value. The data acquisition and processing module 50 is also used to control the charging power access module 10 to charge the battery 30 based on the voltage value of the battery 30 when the charging power access module 10 is connected to the charging power source. The power display module 70 is connected to the data acquisition and processing module 50 and is used to display the battery capacity value of the battery 30.

[0063] Specifically, when detecting the battery level of battery 30, the current sampling value on the current sampling resistor 40 is amplified by the current amplification module 20. After the current sampling value is amplified, the data acquisition and processing module 50 acquires the amplified current sampling value and also acquires the voltage value of battery 30. Then, based on the acquired current sampling value and the voltage value of battery 30, the battery level of battery 30 is determined. After the battery level of battery 30 is determined, the data acquisition and processing module 50 also controls the charging source access module 10 to connect to the charging source when the charging source access module 10 is connected, so that the charging source charges battery 30. In addition, after the battery level of battery 30 is determined, the data acquisition and processing module 50 also transmits the determined battery level value to the power display module 70 so that the battery level of battery 30 is displayed in the power display module 70. When setting the current amplification module 20, the amplification factor of the current amplification module 20 can be determined according to the detection needs. For example, when the current sampling value is small, a current amplification module 20 with a large amplification factor can be selected, and when the current sampling value is large, a current amplification module 20 with a small amplification factor can be selected.

[0064] In this embodiment, when the data acquisition and processing module 50 acquires the current sample value, the current sample value on the current sampling resistor 40 is first amplified by the current amplification module 20. Therefore, the data acquisition and processing module 50 can acquire a small current sample value, improving detection accuracy. In addition, no power detection chip is required, reducing costs. Specifically, when the data acquisition and processing module 50 determines the battery power, it uses the SOC (State of Charge) algorithm.

[0065] Furthermore, such as Figure 1 As shown, the low-cost, high-precision battery power detection circuit also includes a first voltage regulator module 60, which has a voltage input terminal and a voltage output terminal. The voltage input terminal of the first voltage regulator module 60 is connected to the battery 30, and the voltage output terminal of the first voltage regulator module 60 is connected to the data acquisition and processing module 50, the current amplification module 20, and the battery 30 power display module 70, respectively.

[0066] In the embodiment, the battery 30 can supply power to the data acquisition and processing module 50, the current amplification module 20 and the battery 30 power display module 70 through the first voltage stabilizing module 60. The first voltage stabilizing module 60 can ensure stable power supply while meeting the power supply requirements of the data acquisition and processing module 50, the current amplification module 20 and the battery 30 power display module 70. Of course, a separate power supply can also be provided to supply power to the data acquisition and processing module 50, the current amplification module 20 and the battery 30 power display module 70, i.e., the battery 30 does not need to supply power to the data acquisition and processing module 50, the current amplification module 20 and the battery 30 power display module 70.

[0067] In some embodiments, as shown in Figure 2 、 Figure 3 , the current amplification module 20 can include a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2 and a first chip U1; one end of the first resistor R1 is connected to one end of the current sampling resistor 40, and the other end of the first resistor R1 is connected to the 5th pin of the first chip U1; one end of the second resistor R2 is connected to the other end of the current sampling resistor 40, and the other end of the second resistor R2 is connected to the 4th pin of the first chip U1; one end of the third resistor R3 is connected to the 6th pin of the first chip U1, and the other end of the third resistor R3 is connected to the data acquisition and processing module 50; one end of the first capacitor C1 is connected to the voltage output end of the first voltage stabilizing module 60 and the 3rd pin of the first chip U1, and the other end of the first capacitor C1 is connected to the 1st pin of the first chip U1 and the data acquisition and processing module 50; one end of the second capacitor C2 is connected to the 5th pin of the first chip U1, and the other end of the second capacitor C2 is connected to the 4th pin of the first chip U1; the 2nd pin of the first chip U1 is connected to the 1st pin of the first chip U1.

[0068] In the embodiment, the first resistor R1 and the second resistor R2 are voltage dividing resistors, and the first chip U1 can be, but is not limited to, a chip of model SGMS8199. When charging the battery 30, the current value on the current sampling resistor 40 is amplified by the first chip U1. Similarly, when discharging the battery 30, the current value on the current sampling resistor 40 is amplified by the first chip U1.

[0069] Further, as shown in Figure 2 、 Figure 3 , the current amplification module 20 further includes a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5; one end of the third capacitor C3 is connected to the other end of the first resistor R1, and the other end of the third capacitor C3 is grounded; one end of the fourth capacitor C4 is connected to the other end of the second resistor R2, and the other end of the fourth capacitor C4 is grounded; one end of the fifth capacitor C5 is connected to the other end of the third resistor R3, and the other end of the fifth capacitor C5 is grounded.

[0070] In this embodiment, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are all filter capacitors. The third capacitor C3 filters out interference signals in the voltage signal flowing to pin 5 of the first chip U1 through the first resistor R1; the fourth capacitor C4 filters out interference signals in the voltage signal flowing to pin 4 of the first chip U1 through the second resistor R2; and the fifth capacitor C5 filters out interference signals in the voltage signal flowing to pin 6 of the first chip U1.

[0071] In some instances, such as Figure 3 , Figure 4 As shown, the data acquisition and processing module 50 may include a first switch unit 501 and a second chip U2; pins 2, 5, and 17 of the second chip U2 are connected to the charging power access module 10, pins 6 and 14 of the second chip U2 are connected to the current amplification module 20, pins 15 and 20 of the second chip U2 are connected to the battery 30 via the first switch unit 501, pin 7 of the second chip U2 is grounded, and pin 10 of the second chip U2 is connected to the first voltage regulator module 60. The second chip U2 is used to acquire the current sampling value and the voltage value of the battery 30, and to determine the capacity value of the battery 30 based on the current sampling value and the voltage value of the battery 30; the second chip U2 is also used to control the charging power access module 10 to charge the battery 30 based on the voltage value of the battery 30 when the charging power access module 10 is connected to the charging power source, wherein when the first switch unit 501 is in the closed state, the second chip U2 acquires the voltage value of the battery 30.

[0072] Specifically, the first switch unit 501 includes an open state and a closed state. Pin 6 of the second chip U2 is connected to pin 1 of the first chip U1, and pin 14 of the second chip U2 is connected to one end of the fifth capacitor C5 (i.e., pin 14 of the second chip U2 is connected to pin 6 of the first chip U1). The second chip U2 can be an FT61F145-TRB chip.

[0073] When the battery 30 is detected, the voltage value of the battery 30 and the current sampling value on the current detection resistor need to be determined. Since the second chip U2 obtains the voltage value of the battery 30 only when the first switch unit 501 is closed, when the battery 30 needs to be detected, the first switch unit 501 can be controlled to be in a closed state, and then the voltage value of the battery 30 is obtained to detect the battery 30. When the battery 30 does not need to be detected, the first switch unit 501 can be controlled to be in an open state, and the voltage value of the battery 30 is not obtained. Therefore, the low-cost high-precision battery capacity detection circuit does not need to obtain the voltage value of the battery 30 in real time (only when the battery 30 needs to be detected), and the calculation amount of the second chip U2 is reduced.

[0074] Further, as shown in Figure 4 , the tenth pin of the second chip U2 is also provided with a filter capacitor (the nineteenth capacitor C19). One end of the nineteenth capacitor C19 is connected with the tenth pin of the second chip U2, and the other end of the nineteenth capacitor C19 is grounded.

[0075] Further, as shown in Figure 3 , the first switch unit 501 can include a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a sixth capacitor C6, a second switch tube Q2, and a second switch tube Q2; one end of the fourth resistor R4 is connected with the positive electrode of the battery 30, the other end of the fourth resistor R4 is connected with one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected with the collector of the first switch tube Q1, one end of the sixth resistor R6 is connected with the base of the first switch tube Q1, the other end of the sixth resistor R6 is connected with the fifteenth pin of the second chip U2, one end of the seventh resistor R7 is connected with the base of the first switch tube Q1, the other end of the seventh resistor R7 is connected with the emitter of the first switch tube Q1, and the emitter of the first switch tube Q1 is grounded; the source of the second switch tube Q2 is connected with the positive electrode of the battery 30, the gate of the second switch tube Q2 is connected with the other end of the fourth resistor R4, the drain of the second switch tube Q2 is connected with one end of the eighth resistor R8, the other end of the eighth resistor R8 is connected with one end of the ninth resistor R9, the other end of the ninth resistor R9 is grounded, and the other end of the eighth resistor R8 is also connected with the twentieth pin of the second chip U2; one end of the sixth capacitor C6 is connected to the connection path of the other end of the eighth resistor R8 and the twentieth pin of the second chip U2, and the other end of the sixth capacitor C6 is grounded.

[0076] In this embodiment, the first switch Q1 is an NPN transistor; the second switch Q2 is a P-MOS transistor (Positive Channel Metal Oxide Semiconductor).

[0077] When the first switch unit 501 is in the closed state, a high-level signal is output to the first switch Q1 through pin 15 of the second chip U2. At this time, the first switch Q1 is in the conducting state. After the first switch Q1 is in the conducting state, the second switch Q2 is also turned on. The positive terminal of the battery 30 is connected to pin 20 of the second chip U2. At this time, the second chip U2 can obtain the voltage value of the battery 30.

[0078] In this embodiment, the fourth resistor R4, the fifth resistor R5, the eighth resistor R8, and the ninth resistor R9 are voltage divider resistors, the sixth resistor R6 is the driving resistor for the first switching transistor Q1, the seventh resistor R7 is the bleeder resistor for the first switching transistor Q1, and the sixth capacitor C6 is a filter capacitor.

[0079] Furthermore, a filter capacitor (fourteenth capacitor C14) is provided at the source of the second switch Q2. One end of the fourteenth capacitor C14 is connected to the source of the second switch Q2, and the other end of the fourteenth capacitor C14 is grounded.

[0080] In some embodiments, such as Figure 3 As shown, the charging power access module 10 may include a second switch unit 103, a first interface unit 101, and a charging power access signal detection unit 102. The second switch unit 103 is connected to the data acquisition and processing module 50. The first interface unit 101 is connected to the battery 30 via the second switch unit 103 and is used to access the charging power source. The charging power access signal detection unit 102 is connected to both the first interface unit 101 and the data acquisition and processing module 50. The charging power access signal detection unit 102 is used to output a first status signal, which includes a connection status between the first interface unit 101 and the charging power source and a disconnect status between the first interface unit 101 and the charging power source. When the first status signal is a connection status between the first interface unit 101 and the charging power source, the data acquisition and processing module 50 controls the second switch unit 103 according to the voltage value of the battery 30 to charge the battery 30.

[0081] Specifically, the second switch unit 103 includes an open state and a closed state, and the second switch unit 103 is connected to pin 17 of the second chip U2. The charging power input signal detection unit 102 is connected to pins 2 and 5 of the second chip U2.

[0082] In this embodiment, when charging the battery 30, when the first interface unit 101 is connected to the charging source, the charging source connection signal detection unit 102 will detect that the first interface unit 101 is connected to the charging source and output a first status signal (the connection status of the first interface unit 101 and the charging source) to the second chip U2. At this time, the second chip U2 controls the second switch unit 103 according to the obtained voltage value of the battery 30. When the battery 30 needs to be charged, the second switch unit 103 is controlled to close, and the charging source is connected to the battery 30 through the first interface unit 101 for charging. When the battery 30 does not need to be charged, the second switch unit 103 is controlled to close, and the first interface unit 101 does not connect the charging source to the battery 30. Thus, when the battery 30 does not need to be charged, the charging source will not be connected to the battery 30, which can protect the battery 30.

[0083] In some embodiments, such as Figure 3 As shown, the first interface unit 101 may include a tenth resistor R10, an eleventh resistor R11, a seventh capacitor C7, and a first interface J1; pin 1 and pin 2 of the first interface J1 are shorted together, pin 3 of the first interface J1 is connected to one end of the tenth resistor R10, and the other end of the tenth resistor R10 is grounded, pin 4 of the first interface J1 is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is grounded, pin 5 and pin 6 of the first interface J1 are both grounded, one end of the seventh capacitor C7 is connected to pin 1 of the first interface J1, and the other end of the seventh capacitor C7 is grounded.

[0084] The second switching unit 103 may include a first diode D1, a third switch Q3, a fourth switch Q4, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a fifteenth resistor R15; the anode of the first diode D1 is connected to pin 1 of the first interface J1, the cathode of the first diode D1 is connected to the source of the third switch Q3, and the drain of the third switch Q3 is connected to the positive terminal of the battery 30; one end of the twelfth resistor R12 is connected to the source of the third switch Q3, and the other end of the twelfth resistor R12 is connected to the source of the third switch Q3. The gate of transistor Q3 is connected to the thirteenth resistor R13. One end of the thirteenth resistor R13 is connected to the other end of the twelfth resistor R12. The other end of the thirteenth resistor R13 is connected to the collector of the fourth switch transistor Q4. The base of the fourth switch transistor Q4 is connected to one end of the fourteenth resistor R14. The emitter of the fourth switch transistor Q4 is grounded. The other end of the fourteenth resistor R14 is connected to the data acquisition and processing module 50. One end of the fifteenth resistor R15 is connected to one end of the fourteenth resistor R14. The other end of the fifteenth resistor R15 is connected to the emitter of the fourth switch transistor Q4.

[0085] The charging source access signal detection unit 102 can include a sixteenth resistor R16, a seventeenth resistor R17, and an eighth capacitor C8; one end of the sixteenth resistor R16 is connected with one end of the seventh capacitor C7, the other end of the sixteenth resistor R16 is connected with one end of the seventeenth resistor R17, the other end of the seventeenth resistor R17 and the other end of the sixteenth resistor R16 are connected with the data acquisition and processing module 50, one end of the eighth capacitor C8 is connected with the other end of the sixteenth resistor R16, the other end of the eighth capacitor C8 is connected with the other end of the seventeenth resistor R17.

[0086] Specifically, the first interface J1 can be a USB interface. The third switch tube Q3 is a P-MOS tube; the fourth switch tube Q4 is an NPN type triode. The other end of the fourteenth resistor R14 is connected with the 17th pin of the second chip U2. The connection end of the sixteenth resistor R16 and the seventeenth resistor R17 is connected with the 2nd pin of the second chip U2, the other end of the seventeenth resistor R17 is connected with the 5th pin of the second chip U2.

[0087] In the embodiment, when the charging source accesses the first interface J1, then the output voltage of the charging source is divided into two paths at the connection end of the sixteenth resistor R16 and the seventh capacitor C7, one of which flows to the third switch tube Q3, and the other flows to the second chip U2 through the sixteenth resistor R16, that is, outputs a high-level signal to the second chip U2, at this time, the second chip U2 controls the fourth switch tube Q4 according to the voltage value of the battery 30 obtained, wherein when the battery 30 needs to be charged, the fourth switch tube Q4 is controlled to be in a closed state, at this time, the third switch tube Q3 is also closed, then the battery 30 starts to charge; when the battery 30 does not need to be charged, the fourth switch tube Q4 is controlled to be in an open state, at this time, the third switch tube Q3 is also in an open state, at this time, the battery 30 is not charged.

[0088] Further, the drain of the third switch tube Q3 is provided with a filter capacitor (the twelfth capacitor C12 and the thirteenth capacitor C13), one end of the twelfth capacitor C12 and one end of the thirteenth capacitor C13 are commonly connected to the drain of the third switch tube Q3, the other end of the twelfth capacitor C12 and the other end of the thirteenth capacitor C13 are commonly grounded.

[0089] In some embodiments, as shown in Figure 3 , Figure 5 The voltage input end of the first voltage stabilizing module 60 is also connected with the 1st pin of the first interface J1.

[0090] Specifically, as shown in Figure 5As shown, the first voltage stabilizing module 60 can include a third chip U3, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, an eighteenth resistor R18, a second diode D2 and a third diode D3; the positive pole of the second diode D2 is connected with the positive pole of the battery 30, the negative pole of the second diode D2 is connected with one end of the eighteenth resistor R18, the other end of the eighteenth resistor R18 is connected with the second pin of the third chip U3, the positive pole of the third diode D3 is connected with the first pin of the first interface J1, the negative pole of the third diode D3 is connected with one end of the eighteenth resistor R18, one end of the ninth capacitor C9 is connected with the second pin of the third chip U3, one end of the tenth capacitor C10 and one end of the eleventh capacitor C11 are connected with the third pin of the third chip U3, the other end of the ninth capacitor C9, the other end of the tenth capacitor C10, the other end of the eleventh capacitor C11 and the first pin of the third chip U3 are grounded, and the third pin of the third chip U3 is also connected with the first pin of the first chip U1, the tenth pin of the second chip U2 and the battery power display module 70; wherein the third pin of the third chip U3 is the voltage output end of the first voltage stabilizing module 60, and the positive pole of the second diode D2 and the positive pole of the third diode D3 are the voltage input ends of the first voltage stabilizing module 60, that is, the first voltage stabilizing module 60 has two voltage input ends, one is the positive pole of the second diode D2, and the other is the positive pole of the third diode D3, wherein the third chip U3 can output a direct current voltage of +3.3V, and the third chip U3 can be a chip with a model number of ME6239A33PG.

[0091] In the embodiment, when the first voltage stabilizing module 60 supplies power to the data acquisition and processing module 50, the current amplifying module 20 and the battery power display module 70, the power supply is connected through the positive pole of the second diode D2 or the positive pole of the third diode D3, and the power supply voltage is output through the third pin of the third chip U3 to the third pin of the first chip U1, the tenth pin of the second chip U2 and the battery power display module 70. When the charging power is connected, the third chip U3 is supplied with power by the charging power, and the charging speed can be provided (the battery 30 does not supply power to the third chip U3, and the consumption of the battery 30 is saved).

[0092] In some embodiments, as shown in Figure 1 The low-cost high-precision battery power detection circuit further includes a temperature detection module 80, which is connected with the battery 30 and the data acquisition and processing module 50, and is used to acquire the temperature signal of the battery 30 and transmit it to the data acquisition and processing module 50.

[0093] Specifically, the temperature detection module 80 can be a temperature detection circuit with a thermistor NTC as the temperature detection end, as shown in Figure 6 which is the specific circuit structure of the temperature detection module 80, Figure 6The NTC in the temperature sensor can be attached to the surface of the battery 30, Figure 6 The connection end of the nineteenth resistor R19 and the twentieth resistor R20 in the temperature sensor is connected with the 19th pin of the second chip U2, and the temperature of the battery 30 can be detected in real time through the temperature detection module 80, and the temperature detection signal is transmitted to the second chip U2 in real time, so that the temperature of the battery 30 can be detected.

[0094] In some embodiments, as shown in Figure 7 , Figure 8 The power display module 70 can be a power display module 70 with the fourth chip U4 and a liquid crystal display (LCD) as core devices. Figure 7 , Figure 8 As shown in the specific circuit structure of the power display module 70, the model of the fourth chip U4 is TM1621DQSOP24, and the model of the liquid crystal display is JLX12864G-086-PN.

[0095] In the embodiment, the liquid crystal display is connected with the fourth chip U4 through the second interface J2, the 15th pin of the fourth chip U4 is connected with the voltage output end (the 3rd pin of the third chip U3) of the first voltage stabilizing module 60, the 10th pin, the 11th pin and the 12th pin of the fourth chip U4 are respectively connected with the voltage output end of the first voltage stabilizing module 60 through a pull-up resistor (the 30th resistor R30, the 31st resistor R31 and the 32nd resistor R32), the 10th pin of the fourth chip U4 is further connected with the 11th pin of the second chip U2 through the 33rd resistor R33, the 11th pin of the fourth chip U4 is further connected with the 12th pin of the second chip U2 through the 34th resistor R34, and the 12th pin of the fourth chip U4 is further connected with the 3rd pin of the second chip U2 through the 35th resistor R35.

[0096] The low-cost high-precision battery power detection circuit can be applied to, but is not limited to, electronic products with rechargeable batteries such as floor cleaning machines, floor washing machines, vacuum cleaners, hair clippers, etc. Figure 9 As shown in the load driving circuit driven by the low-cost high-precision battery power detection circuit, the low-cost high-precision battery power detection circuit and the load driving circuit, and the load driving circuit and the motor, the motor can be driven.

[0097] In the embodiment, the determined power value is transmitted to the fourth chip U4 through the second chip U2, and the liquid crystal display is further driven by the fourth chip U4 to display the power value of the battery 30.

[0098] In summary, the low-cost high-precision battery power detection circuit has the following effects:

[0099] When the data acquisition and processing module 50 acquires the current sampling value, the current sampling value on the current sampling resistor 40 is amplified by the current amplification module 20 first, therefore, the data acquisition and processing module 50 can acquire the tiny current sampling value, the detection precision is improved, and in addition, the electric quantity detection chip is not needed, and the cost is reduced.

[0100] It can be understood that the above embodiments only express the preferred embodiments of the present application, the description is more specific and detailed, but it cannot be understood as the limitation of the patent scope of the present application; it should be pointed out that for the ordinary skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and a number of modifications and improvements can be made, which belong to the protection scope of the present application; therefore, any equivalent transformation and modification within the scope of the claims of the present application should belong to the scope of the claims of the present application.

Claims

1. A low-cost high-precision battery power detection circuit, characterized in that, The application relates to a battery charging system, which comprises the following parts: a charging source access module connected with the positive and negative poles of a battery, wherein a current sampling resistor is connected in series on the connecting path of the charging source access module and the negative pole of the battery, and the charging source access module is used for accessing a charging source; a current amplification module connected with the current sampling resistor, which is used for amplifying the sampling current on the current sampling resistor and outputting a current sampling value; a data acquisition and processing module connected with the charging source access module, the current amplification module and the battery, which is used for acquiring the current sampling value and the voltage value of the battery, and determining the power value of the battery according to the current sampling value and the voltage value of the battery; the data acquisition and processing module is also used for controlling the charging source access module according to the voltage value of the battery when the charging source access module accesses the charging source, so that the charging source charges the battery; a power display module connected with the data acquisition and processing module, which is used for displaying the power value of the battery.

2. The low cost high accuracy battery charge detection circuit of claim 1, wherein, The application further comprises: a first voltage stabilizing module with a voltage input end and a voltage output end, wherein the voltage input end of the first voltage stabilizing module is connected with the battery, and the voltage output end of the first voltage stabilizing module is connected with the data acquisition and processing module, the current amplification module and the power display module respectively.

3. The low cost high accuracy battery charge detection circuit of claim 2, wherein, The current amplification module comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first chip. One end of the first resistor is connected with one end of the current sampling resistor, and the other end of the first resistor is connected with the 5th pin of the first chip. One end of the second resistor is connected with the other end of the current sampling resistor, and the other end of the second resistor is connected with the 4th pin of the first chip. One end of the third resistor is connected with the 6th pin of the first chip, and the other end of the third resistor is connected with the data acquisition and processing module. One end of the first capacitor is connected with the voltage output end of the first voltage stabilizing module and the 3rd pin of the first chip, and the other end of the first capacitor is connected with the 1st pin of the first chip and the data acquisition and processing module. One end of the second capacitor is connected with the 5th pin of the first chip, and the other end of the second capacitor is connected with the 4th pin of the first chip. The 2nd pin of the first chip is connected with the 1st pin of the first chip.

4. The low cost high accuracy battery charge detection circuit of claim 3, wherein, The current amplification module further comprises a third capacitor, a fourth capacitor and a fifth capacitor. One end of the third capacitor is connected with the other end of the first resistor, and the other end of the third capacitor is grounded. One end of the fourth capacitor is connected with the other end of the second resistor, and the other end of the fourth capacitor is grounded. One end of the fifth capacitor is connected with the other end of the third resistor, and the other end of the fifth capacitor is grounded.

5. The low cost high accuracy battery charge detection circuit of claim 2, wherein, The data acquisition and processing module comprises: a first switch unit; A second chip, a 2nd pin, a 5th pin and a 17th pin of the second chip are connected with the charging source access module, a 6th pin and a 14th pin of the second chip are connected with the current amplification module, a 15th pin and a 20th pin of the second chip are connected with the battery through the first switch unit, a 7th pin of the second chip is grounded, a 10th pin of the second chip is connected with the first voltage stabilizing module, the second chip is used for obtaining the current sampling value and the voltage value of the battery, and the second chip is used for determining the power value of the battery according to the current sampling value and the voltage value of the battery; the second chip is also used for controlling the charging source access module according to the voltage value of the battery when the charging source access module accesses the charging source, so that the charging source charges the battery, wherein the second chip obtains the voltage value of the battery when the first switch unit is in a closed state.

6. The low cost high accuracy battery charge detection circuit of claim 5, wherein, The first switch unit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a sixth capacitor, a first switch tube and a second switch tube. One end of the fourth resistor is connected with the positive electrode of the battery, the other end of the fourth resistor is connected with one end of the fifth resistor, the other end of the fifth resistor is connected with the collector of the first switch tube, one end of the sixth resistor is connected with the base of the first switch tube, the other end of the sixth resistor is connected with the 15th pin of the second chip, one end of the seventh resistor is connected with the base of the first switch tube, the other end of the seventh resistor is connected with the emitter of the first switch tube, and the emitter of the first switch tube is grounded. The source of the second switch tube is connected with the positive electrode of the battery, the gate of the second switch tube is connected with the other end of the fourth resistor, the drain of the second switch tube is connected with one end of the eighth resistor, the other end of the eighth resistor is connected with one end of the ninth resistor, the other end of the ninth resistor is grounded, and the other end of the eighth resistor is also connected with the 20th pin of the second chip. One end of the sixth capacitor is connected to the connection path of the other end of the eighth resistor and the 20th pin of the second chip, and the other end of the sixth capacitor is grounded.

7. The low cost high accuracy battery charge detection circuit of claim 2, wherein, The charging source access module comprises: A second switch unit connected with the data acquisition and processing module; A first interface unit used for accessing the charging source, the first interface unit being connected with the battery through the second switch unit; A charging source access signal detection unit connected with the first interface unit and the data acquisition and processing module, the charging source access signal detection unit being used for outputting a first state signal, the first state signal comprising a connection state of the first interface unit and the charging source and a disconnection state of the first interface unit and the charging source; When the first state signal is the connection state of the first interface unit and the charging source, the data acquisition and processing module is used for controlling the second switch unit according to the voltage value of the battery, so that the charging source charges the battery.

8. The low cost high accuracy battery charge detection circuit of claim 7, wherein, The first interface unit comprises a tenth resistor, an eleventh resistor, a seventh capacitor and a first interface. The first pin and the second pin of the first interface are shorted, the third pin of the first interface is connected with one end of the tenth resistor, the other end of the tenth resistor is grounded, the fourth pin of the first interface is connected with one end of the eleventh resistor, the other end of the eleventh resistor is grounded, the fifth pin of the first interface is connected with the sixth pin of the first interface, one end of the seventh capacitor is connected with the first pin of the first interface, and the other end of the seventh capacitor is grounded. The second switch unit comprises a first diode, a third switch tube, a fourth switch tube, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a fifteenth resistor. The anode of the first diode is connected with the first pin of the first interface, the cathode of the first diode is connected with the source of the third switch tube, and the drain of the third switch tube is connected with the anode of the battery. One end of the twelfth resistor is connected with the source of the third switch tube, the other end of the twelfth resistor is connected with the gate of the third switch tube, one end of the thirteenth resistor is connected with the other end of the twelfth resistor, the other end of the thirteenth resistor is connected with the collector of the fourth switch tube, the base of the fourth switch tube is connected with one end of the fourteenth resistor, and the emitter of the fourth switch tube is grounded. The other end of the fourteenth resistor is connected with the data acquisition and processing module, one end of the fifteenth resistor is connected with one end of the fourteenth resistor, and the other end of the fifteenth resistor is connected with the emitter of the fourth switch tube. The charging source access signal detection unit comprises a sixteenth resistor, a seventeenth resistor and an eighth capacitor. One end of the sixteenth resistor is connected with one end of the seventh capacitor, the other end of the sixteenth resistor is connected with one end of the seventeenth resistor, the other end of the seventeenth resistor and the other end of the sixteenth resistor are connected with the data acquisition and processing module, one end of the eighth capacitor is connected with the other end of the sixteenth resistor, and the other end of the eighth capacitor is connected with the other end of the seventeenth resistor.

9. The low cost high accuracy battery charge detection circuit of claim 8, wherein, The voltage input end of the first voltage stabilizing module is also connected with the first pin of the first interface.

10. The low cost high accuracy battery charge detection circuit according to claim 1 or 2, wherein, The low-cost high-precision battery power detection circuit further comprises a temperature detection module connected with the battery and the data acquisition and processing module, and the temperature detection module is used to collect the temperature signal of the battery and transmit the temperature signal to the data acquisition and processing module.

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