Voltage and current bidirectional measurement circuit for coulombmeter

Abstract

The measuring circuit comprises a digital-to-analog conversion chip, a voltage sampling circuit, a current sampling circuit and a 3.3 V LDO voltage stabilizing circuit, the digital-to-analog conversion chip comprises an A0 pin, an A1 pin, an A2 pin, an A3 pin, an SCL pin and an SDA pin, the A0 pin and the A1 pin are electrically connected with a resistor R4, a resistor R5, a resistor R1, a resistor C2 and a resistor C3, the A2 pin is electrically connected with an R6, an R3, an R2 and a C4, the current sampling circuit is electrically connected with the 3.3 V LDO voltage stabilizing circuit, and the 3.3 V LDO voltage stabilizing circuit is electrically connected with the 3.3 V LDO voltage stabilizing circuit. The A3 pin is electrically connected with the R7, and the SCL pin and the SDA pin are electrically connected with the R8 and the R9. According to the utility model, a rapid, accurate and reliable detection method is provided, the method is durable and low in cost, the measuring range of sampling voltage and current can be adjusted according to actual requirements, the circuit design is simplified, and the manufacturing cost is remarkably reduced.

Description

Technical Field

[0001] The present application relates to the technical field of instrument measurement, and in particular to a voltage and current bidirectional measurement circuit for a coulomb meter. Background Art

[0002] With the widespread application of battery technology, the remaining power, current voltage, current and power of the battery during use have become extremely important. In order to understand the status of the battery, it is necessary to measure the current and voltage of the battery to determine whether the battery is in a normal charging and discharging state. The common sampling method is to amplify the current through the Hall current sensor and send it to the ADC for detection;

[0003] However, due to the high cost and large error of the Hall transformer, it is not applicable in some precise current measurement occasions. Therefore, for small energy storage devices, a current measurement circuit with simple structure, economical applicability and easy debugging is needed to simplify the design and reduce the cost. To this end, we propose a voltage and current bidirectional measurement circuit to solve the above problems.

[0004] The above information disclosed in the background technology is only used to increase the understanding of the background technology of the present application, and therefore, it may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0005] In order to solve the problem that with the widespread application of battery technology, the remaining power, current voltage, current and power of the battery during use have become extremely important. In order to understand the status of the battery, it is necessary to measure the current and voltage of the battery to determine whether the battery is in a normal charge and discharge state. The common sampling method is to amplify the current through a Hall current sensor and then send it to the ADC for detection. However, due to the high cost and large error of the Hall transformer, it is not suitable for some precision current measurement occasions. Therefore, for small energy storage devices, a current measurement circuit with a simple structure, economical applicability and easy debugging is needed to simplify the design and reduce costs. The present application provides a voltage and current bidirectional measurement circuit for a coulomb meter.

[0006] The present application provides a voltage and current bidirectional measurement circuit for a coulomb meter using the following technical solution:

[0007] A voltage and current bidirectional measurement circuit for a coulomb meter comprises a digital-to-analog conversion chip, a voltage sampling circuit, a current sampling circuit, and a 3.3V LDO voltage stabilization circuit. The digital-to-analog conversion chip comprises an A0 pin, an A1 pin, an A2 pin, an A3 pin, an SCL pin, and an SDA pin. The A0 and A1 pins are electrically connected to resistors R4, R5, R1, C2, and C3. The A2 pin is electrically connected to R6, R3, R2, and C4. The A3 pin is electrically connected to R7. The SCL and SDA pins are electrically connected to R8 and R9.

[0008] Preferably, the digital-to-analog conversion chip is a (ADS1112) 16-bit ADC analog-to-digital conversion chip.

[0009] Preferably, the 3.3V LDO includes a voltage stabilizing circuit U2, and the voltage stabilizing circuit U2 is electrically connected to R10, C7, C5, and C6.

[0010] Preferably, the voltage sampling circuit includes a voltage sampling circuit composed of a voltage dividing resistor and a filter capacitor.

[0011] Preferably, the current sampling circuit includes a differential matching resistor and a current sensing resistor.

[0012] Preferably, the 3.3V LDO voltage stabilization circuit includes RT9013, an enabling resistor, and a filter capacitor.

[0013] In summary, this application includes the following beneficial technical effects:

[0014] 1. The utility model provides a fast, accurate and reliable detection method by designing the hardware circuit concisely. The method is not only durable and low-cost, but also the range of sampling voltage and current can be adjusted according to actual needs. The range of input voltage can be adjusted by only changing the voltage divider resistor. This design saves tedious debugging time, simplifies circuit design, and significantly reduces manufacturing costs.

[0015] 2. When the measurement circuit is working normally, the voltage stabilizing circuit composed of RT9013, enabling resistor and filter capacitor provides 3.3V power supply for the digital-to-analog conversion chip, which is connected to the VDD pin of the chip. In addition, the voltage sampling circuit composed of voltage divider resistor and filter capacitor attenuates the 7-100V DC voltage by 100 times and sends it to the A2 pin of the digital-to-analog conversion chip;

[0016] 3. The resistors R4, R5, R1 and the capacitors C2, C3 in the circuit form a differential circuit. When current flows through the two ends of the resistor R1, a voltage drop will be generated. This voltage drop is sent to the A0 and A1 differential pins of the digital-to-analog conversion chip. The current range is determined by the resistor R1, and the differential voltage range is ±2.048 / PGA (1-8). This design makes the current measurement more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of an embodiment of the application;

[0018] Figure 2 It is a schematic diagram of the overall structure of the embodiment of the application;

[0019] Figure 3It is a schematic diagram of the structure of the digital-to-analog conversion chip of the application embodiment. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1-3 This application is described in further detail.

[0021] The present application embodiment discloses a voltage and current bidirectional measurement circuit for a coulomb meter. Figure 1-3 A voltage and current bidirectional measurement circuit for a coulomb meter includes a digital-to-analog conversion chip, a voltage sampling circuit, a current sampling circuit, and a 3.3V LDO voltage stabilization circuit. The digital-to-analog conversion chip includes an A0 pin, an A1 pin, an A2 pin, an A3 pin, an SCL pin, and an SDA pin. The A0 and A1 pins are electrically connected to resistors R4, R5, R1, C2, and C3. The A2 pin is electrically connected to R6, R3, R2, and C4. The A3 pin is electrically connected to R7. The SCL and SDA pins are electrically connected to R8 and R9. The digital-to-analog conversion chip is a (ADS1112) 16-bit ADC analog-to-digital conversion chip.

[0022] When the measurement circuit works normally, the voltage stabilizing circuit composed of RT9013, enable resistor and filter capacitor provides 3.3V power supply for the digital-to-analog conversion chip, which is connected to the VDD pin of the chip. In addition, the voltage sampling circuit composed of voltage divider resistor and filter capacitor attenuates the 7-100V DC voltage by 100 times and sends it to the A2 pin of the digital-to-analog conversion chip. The resistors R4, R5, R1 and capacitors C2 and C3 in the circuit form a differential circuit. When current flows through the two ends of resistor R1, a voltage drop will be generated. This voltage drop is sent to the A0 and A1 differential pins of the digital-to-analog conversion chip. The current range is determined by resistor R1, and the differential voltage range is ±2.048 / PGA (1-8).

[0023] Reference Figure 1 The 3.3V LDO includes a voltage stabilizing circuit U2, and the voltage stabilizing circuit U2 is electrically connected to R10, C7, C5, and C6.

[0024] Reference Figure 1 The voltage sampling circuit includes a voltage sampling circuit composed of a voltage dividing resistor and a filter capacitor, and the current sampling circuit includes a differential matching resistor and a current sensing resistor.

[0025] Reference Figure 1 , 3.3V LDO voltage regulator circuit includes RT9013, enabling resistor and filter capacitor.

[0026] The implementation principle of a voltage and current bidirectional measurement circuit for a coulomb meter in the embodiment of the present application is as follows: when the measurement circuit works normally, a voltage stabilizing circuit composed of RT9013, an enabling resistor and a filter capacitor provides a 3.3V power supply to the digital-to-analog conversion chip, and the power supply is connected to the VDD pin of the chip. In addition, a voltage sampling circuit composed of a voltage dividing resistor and a filter capacitor attenuates a 7-100V DC voltage by 100 times and then sends it to the A2 pin of the digital-to-analog conversion chip. The specific measurement range is determined by the voltage dividing ratio;

[0027] In addition, the resistors R4, R5, R1 and the capacitors C2, C3 in the circuit form a differential circuit. When current flows through the two ends of the resistor R1, a voltage drop will be generated. This voltage drop is sent to the A0 and A1 differential pins of the digital-to-analog conversion chip. The current range is determined by the resistor R1, and the differential voltage range is ±2.048 / PGA (1-8). This design makes the current measurement more accurate and reliable.

[0028] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0029] Secondly: In the drawings of the embodiments disclosed in the present utility model, only the structures related to the embodiments disclosed in the present utility model are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present utility model can be combined with each other;

[0030] Finally: The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.

[0031] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A voltage and current bidirectional measurement circuit for a coulomb meter, comprising a digital-to-analog conversion chip, a voltage sampling circuit, a current sampling circuit, and a 3.3V LDO voltage stabilization circuit, characterized in that: The digital-to-analog conversion chip includes an A0 pin, an A1 pin, an A2 pin, an A3 pin, an SCL pin and an SDA pin. The A0 and A1 pins are electrically connected to resistors R4, R5, R1, C2 and C3. The A2 pin is electrically connected to R6, R3, R2 and C4. The A3 pin is electrically connected to R7. The SCL and SDA pins are electrically connected to R8 and R9.

2. A voltage and current bidirectional measurement circuit for a coulomb meter according to claim 1, characterized in that: The digital-to-analog conversion chip is an ADS1112 16-bit ADC analog-to-digital conversion chip.

3. A voltage and current bidirectional measurement circuit for a coulomb meter according to claim 2, characterized in that: The 3.3V LDO includes a voltage stabilizing circuit U2 , and the voltage stabilizing circuit U2 is electrically connected to R10 , C7 , C5 , and C6 .

4. A voltage and current bidirectional measurement circuit for a coulomb meter according to claim 3, characterized in that: The voltage sampling circuit comprises a voltage sampling circuit composed of a voltage dividing resistor and a filter capacitor.

5. A voltage and current bidirectional measurement circuit for a coulomb meter according to claim 4, characterized in that: The current sampling circuit includes a differential matching resistor and a current sensing resistor.

6. A voltage and current bidirectional measurement circuit for a coulomb meter according to claim 5, characterized in that: The 3.3V LDO voltage stabilizing circuit comprises RT9013, an enabling resistor and a filtering capacitor.

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