Battery capacity detection circuit with temperature compensation

Abstract

The utility model relates to battery technical field, specifically relates to the battery capacity detection circuit with temperature compensation, it contains voltage stabilizing chip and double -way operation, voltage stabilizing chip's power supply connects to circuit's positive and negative pole circuit, its CE end connects the anode, double -way operation power supply connects to voltage stabilizing chip's output, and the positive and negative pole circuit links with the battery, and there is resistance one and resistance two between the positive and negative pole, and there is resistance three for shunt on resistance two, and resistance three rear -end output VS end, and there is still capacitor two between this end and the negative pole, and VS links with the same phase foot of A, B two channels in double -way operation respectively, and still be equipped with pilot lamp one and pilot lamp two in the circuit, and still connects trigger mechanism one and trigger mechanism two on voltage stabilizing chip's output, and they are connected respectively OA end and OB for controlling pilot lamp one and pilot lamp two, the present application adopts the circuit directly to carry out battery detection, and does not depend on the program control of singlechip or chip, and the device cost is low, and the manufacturing cost is low and the component acquisition is easy.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery capacity detection circuit with temperature compensation. Background Technology

[0002] In existing battery-powered devices, the battery voltage gradually decreases as the battery power is depleted. Therefore, it is necessary to monitor the battery voltage during use and issue a warning when the battery voltage is too low. In existing technologies, one method is to directly use a resistor divider to drive an indicator light. However, due to the unstable voltage threshold, the indicator light is prone to flashing repeatedly at the critical point, resulting in poor reliability. Another method is to use a microcontroller to sample the voltage and combine it with software calculations to determine the remaining battery capacity. However, this method has a complex circuit structure, high power consumption, requires specialized software, and occupies a certain amount of chip processing space, resulting in a high overall cost. Utility Model Content

[0003] The purpose of this invention is to address the deficiencies and shortcomings of existing technologies by providing a reasonably designed battery capacity detection circuit with temperature compensation, which can solve the aforementioned deficiencies.

[0004] To achieve the above objectives, this utility model adopts the following technical solution: It includes a voltage regulator chip and a dual operational amplifier. The power supply of the voltage regulator chip is connected to the positive and negative lines of the circuit, and its CE terminal is connected to the positive terminal. The power supply of the dual operational amplifier is connected to the output terminal of the voltage regulator chip. The positive and negative lines are connected to the battery, and resistors one and two are connected in series between the positive and negative terminals. Resistor three is connected in parallel with resistor two for current shunting. The output of resistor three is VS terminal. Capacitor two is connected in series between this terminal and the negative terminal. VS is connected to the non-inverting pins of channels A and B of the dual operational amplifier respectively. The circuit also includes indicator light one and indicator light two. Trigger mechanism one and trigger mechanism two are connected to the output terminal of the voltage regulator chip. The two are respectively connected to the OA terminal and OB terminal for controlling indicator light one and indicator light two.

[0005] Preferably, the triggering mechanism includes a potentiometer. A resistor is connected in series between the upper end of the potentiometer and the output terminal of the voltage regulator chip, and a thermistor is connected in series between the lower end and the negative terminal. The slider end of the potentiometer is connected to the inverting input terminal of the A channel in the dual-channel operational amplifier. The output connection port of the A channel is the OA terminal. A resistor is also connected in series between this port and the inverting input terminal of the A channel. A capacitor is also connected between the inverting input terminal of the A channel and the negative terminal.

[0006] Preferably, the triggering mechanism two includes a potentiometer two. A resistor five is connected in series between the upper end of the potentiometer two and the output terminal of the voltage regulator chip, and a thermistor two is connected in series between the lower end and the negative terminal. The slider end of the potentiometer two is connected to the inverting input terminal of the B channel in the dual-channel operational amplifier. The output connection port of the B channel is the OB terminal. A resistor eight is also connected in series between this port and the inverting input terminal of the B channel. A capacitor four is also connected between the inverting input terminal of the B channel and the negative terminal.

[0007] Preferably, the positive terminal of the indicator light is connected to the output terminal of the voltage regulator chip, and the other end is connected to a field-effect transistor (FET) through a resistor eleven. The resistor eleven is connected to the drain, the gate of the FET is connected to the OA terminal through a resistor nine, and the source is connected to the negative terminal of the circuit.

[0008] Preferably, the positive terminal of the second indicator light is connected to the output terminal of the voltage regulator chip, and the other end is connected to the second field-effect transistor through a resistor seven. The resistor seven is connected to the drain, the gate of the second field-effect transistor is connected to the OA terminal through a resistor ten, and the source is connected to the negative terminal of the circuit.

[0009] Preferably, a capacitor for decoupling is provided between the positive and negative terminals in the circuit.

[0010] The beneficial effects of this utility model after adopting the above structure are:

[0011] 1. This application uses a circuit for battery detection, which does not rely on microcontroller or chip program control. The device cost is low, the manufacturing cost is low, and the components are easy to obtain.

[0012] 2. This application uses a voltage regulator chip to provide an independent voltage, ensuring the voltage stability of the detection circuit.

[0013] 3. This application uses a voltage regulator chip and low-side control of the field-effect transistor, resulting in low quiescent current, which is suitable for long-term battery use.

[0014] 4. In this application, the field-effect transistor is isolated from the operational amplifier current, and the current driving the LED or buzzer does not pass through the operational amplifier, and is therefore not limited by the output current of the operational amplifier.

[0015] 5. In this application, the undervoltage trigger voltage value can be easily adjusted by setting the reference voltage with a potentiometer without replacing components or modifying the circuit, making it convenient to use. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the present invention.

[0017] Explanation of reference numerals in the attached figures:

[0018] 1. Resistor 1; 2. Resistor 2; 3. Resistor 3; 4. Resistor 4; 5. Resistor 5; 6. Resistor 6; 7. Resistor 7; 8. Resistor 8; 9. Resistor 9; 10. Resistor 10; 11. Resistor 11; 12. Capacitor 1; 13. Capacitor 2; 14. Capacitor 3; 15. Capacitor 4; 16. Dual-channel operational amplifier; 17. Voltage regulator chip; 18. Potentiometer 1; 19. Potentiometer 2; 20. Thermistor 1; 21. Thermistor 2; 22. Field-effect transistor 1; 23. Field-effect transistor 2; 24. Indicator light 1; 25. Indicator light 2. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] See Figure 1 As shown, it includes a voltage regulator chip 17 and a dual operational amplifier 16. The power supply of the voltage regulator chip 17 is connected to the positive and negative lines of the circuit, and its CE terminal is connected to the positive terminal. The power supply of the dual operational amplifier 16 is connected to the output terminal of the voltage regulator chip 17. The positive and negative lines are connected to the battery, and a resistor 1 and a resistor 2 are connected in series between the positive and negative terminals. A resistor 3 is connected in parallel with the resistor 2 for current shunting. The output of the resistor 3 is the VS terminal. A capacitor 13 is connected in series between the VS terminal and the negative terminal. The VS is connected to the non-inverting pins of the A and B channels of the dual operational amplifier 16. The circuit also includes an indicator light 24 and an indicator light 25. The output terminal of the voltage regulator chip 17 is also connected to a trigger mechanism 1 and a trigger mechanism 2. The two are connected to the OA terminal and the OB terminal for controlling the indicator light 24 and the indicator light 25, respectively.

[0021] The trigger mechanism includes a potentiometer 18, preferably a 10k model. A resistor 4 is connected in series between the upper end of the potentiometer 18 and the output terminal of the voltage regulator chip 17, and a thermistor 20 is connected in series between the lower end and the negative terminal. The slider end of the potentiometer 18 is connected to the inverting input terminal of channel A in the dual-channel operational amplifier 16. The output connection port of channel A is terminal 0A. A resistor 6 is connected in series between this port and the inverting input terminal of channel A. A capacitor 14 is also connected between the inverting input terminal of channel A and the negative terminal.

[0022] The trigger mechanism 2 includes a potentiometer 2 19, preferably a 10k model. A resistor 5 is connected in series between the upper end of potentiometer 2 19 and the output terminal of the voltage regulator chip 17, and a thermistor 21 is connected in series between the lower end and the negative terminal. The slider end of potentiometer 2 19 is connected to the inverting input terminal of channel B in the dual-channel operational amplifier 16. The output connection port of channel B is the OB terminal. A resistor 8 is connected in series between this port and the inverting input terminal of channel B. A capacitor 15 is also connected between the inverting input terminal of channel B and the negative terminal.

[0023] Operational amplifiers can enable two channels to operate separately, perform voltage comparisons, and use resistors and capacitors to hysteresis at the output to filter out short-term fluctuations;

[0024] Both sets of triggering mechanisms use adjustable potentiometers to set the threshold. The upper end is connected to a resistor for pull-up, and the lower end is grounded through an NTC. Therefore, when the temperature rises, the resistance of the NTC decreases, pulling down the lower end, so the voltage in the middle can change with the temperature. By adjusting the threshold, the two potentiometers can achieve low-voltage and relatively high-voltage triggering. That is, under different voltage conditions, the corresponding LED is triggered to light up for warning, such as full charge alarm and low charge alarm, or multi-level low voltage alarm. The LED can also be connected in parallel with a buzzer to enhance the warning effect. The triggering voltage of the LED and the buzzer must be lower than the lower threshold of the alarm to prevent the phenomenon that the alarm cannot be started when the voltage is low.

[0025] The positive terminal of indicator light 24 is connected to the output terminal of voltage regulator chip 17, and the other end is connected to field-effect transistor 22 through resistor 1111. Resistor 1111 is connected to the drain. The gate of field-effect transistor 22 is connected to terminal 0A through resistor 99, and the source is connected to the negative terminal of the circuit.

[0026] The positive terminal of indicator light 25 is connected to the output terminal of voltage regulator chip 17, and the other end is connected to field-effect transistor 23 through resistor 7. Resistor 7 is connected to the drain. The gate of field-effect transistor 23 is connected to terminal 0A through resistor 10, and the source is connected to the negative terminal of the circuit.

[0027] In the circuit, a capacitor 12 is provided between the positive and negative terminals for decoupling.

[0028] In the circuit, the voltage regulator chip 17 outputs a stable voltage to drive the operational amplifier and provide a reference comparison voltage. The actual battery voltage is obtained by voltage division and compared with the two voltage values ​​to determine whether the battery voltage has reached the threshold. When the battery voltage is high, the operational amplifier outputs a high level, the field-effect transistor is cut off, and the LED is off. When the battery voltage is lower than the threshold, the operational amplifier outputs a low level, the field-effect transistor is turned on, and the LED lights up as a warning.

[0029] The installation, connection, or setting methods of the components not detailed above are all common mechanical methods, and the specific structure, model, and coefficient indicators of all their components are their own technologies. As long as they can achieve their beneficial effects, they can be implemented, so they will not be elaborated further.

[0030] It should be understood that the above-described specific embodiments of this utility model are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within the protection scope of this utility model. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A battery capacity detection circuit with temperature compensation, characterized in that: It includes a voltage regulator chip (17) and a dual operational amplifier (16). The power supply of the voltage regulator chip (17) is connected to the positive and negative lines of the circuit, and its CE terminal is connected to the positive terminal. The power supply of the dual operational amplifier (16) is connected to the output terminal of the voltage regulator chip (17). The positive and negative lines are connected to the battery, and a resistor 1 (1) and a resistor 2 (2) are connected in series between the positive and negative terminals. A resistor 3 (3) for shunt is connected to the resistor 2 (2). The output of the resistor 3 (3) is the VS terminal. A capacitor 2 (13) is connected in series between the terminal and the negative terminal. The VS is connected to the in-phase pins of the A and B channels of the dual operational amplifier (16) respectively. The circuit also includes an indicator light 1 (24) and an indicator light 2 (25). The output terminal of the voltage regulator chip (17) is also connected to a trigger mechanism 1 and a trigger mechanism 2. The two are connected to the OA terminal and the OB terminal for controlling the indicator light 1 (24) and the indicator light 2 (25) respectively.

2. The battery capacity detection circuit with temperature compensation according to claim 1, characterized in that: The triggering mechanism includes a potentiometer (18). A resistor (4) is connected in series between the upper end of the potentiometer (18) and the output terminal of the voltage regulator chip (17), and a thermistor (20) is connected in series between the lower end and the negative terminal. The slider end of the potentiometer (18) is connected to the inverting input terminal of the A channel in the dual-channel operational amplifier (16). The output connection port of the A channel is the OA terminal. A resistor (6) is connected in series between this port and the inverting input terminal of the A channel. A capacitor (14) is also connected between the inverting input terminal of the A channel and the negative terminal.

3. The battery capacity detection circuit with temperature compensation according to claim 2, characterized in that: The triggering mechanism 2 includes a potentiometer 2 (19). A resistor 5 (5) is connected in series between the upper end of the potentiometer 2 (19) and the output terminal of the voltage regulator chip (17). A thermistor 2 (21) is connected in series between the lower end and the negative terminal. The slider end of the potentiometer 2 (19) is connected to the inverting input terminal of the B channel in the dual-channel operational amplifier (16). The output connection port of the B channel is the OB terminal. A resistor 8 (8) is connected in series between this port and the inverting input terminal of the B channel. A capacitor 4 (15) is also connected between the inverting input terminal of the B channel and the negative terminal.

4. The battery capacity detection circuit with temperature compensation according to claim 1, characterized in that: The positive terminal of indicator light 1 (24) is connected to the output terminal of voltage regulator chip (17), and the other end is connected to field effect transistor 1 (22) through resistor 11 (11). Resistor 11 (11) is connected to the drain. The gate of field effect transistor 1 (22) is connected to terminal OA through resistor 9 (9), and the source is connected to the negative terminal of the circuit.

5. The battery capacity detection circuit with temperature compensation according to claim 4, characterized in that: The positive terminal of the indicator light 2 (25) is connected to the output terminal of the voltage regulator chip (17), and the other end is connected to the field effect transistor 2 (23) through the resistor 7 (7). The resistor 7 (7) is connected to the drain. The gate of the field effect transistor 2 (23) is connected to the OA terminal through the resistor 10 (10), and the source is connected to the negative terminal of the circuit.

6. The battery capacity detection circuit with temperature compensation according to claim 1, characterized in that: In the circuit, a capacitor (12) is provided between the positive and negative terminals for decoupling.

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