A detection circuit for a current signal

Abstract

This invention provides a current signal detection circuit. The detection circuit operates in a first-degree Celsius environment and includes: a fluxgate current sensor that outputs a first current signal; a precision resistor connected to the fluxgate current sensor and through which the first current signal flows; an operational amplifier circuit that scales a first voltage signal across the precision resistor; a compensation circuit that compensates a second voltage signal output by the operational amplifier circuit into a third voltage signal; and a DSP chip that processes the third voltage signal into a second current signal. The difference between the magnitude of the second voltage signal and the magnitude of a second preset voltage signal output by the detection circuit through the operational amplifier circuit in the second-degree Celsius environment is less than a preset value. The second current signal serves as the current signal detected by the detection circuit in the first-degree Celsius environment. This invention enables accurate measurement of current signals.

Description

Technical Field

[0001] This utility model relates to the field of current detection technology, and in particular to a current signal detection circuit. Background Technology

[0002] Currently, the mainstream current detection technology solutions on the market mainly use resistor shunts, Hall sensors, etc. to detect current. However, the resistance value of the above detection components changes significantly due to temperature changes, that is, the temperature drift is serious, resulting in inaccurate current signals. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a current signal detection circuit. The detection circuit includes: a fluxgate current sensor for acquiring current signals, and a compensation circuit for compensating the voltage signal output by the operational amplifier circuit in the detection circuit under different ambient temperatures, so as to achieve accurate measurement of the current signal detected by the fluxgate current sensor.

[0004] In a first aspect, this utility model provides a current signal detection circuit, wherein the detection circuit is in an environment of a first degree Celsius, comprising:

[0005] The system comprises: a fluxgate current sensor that outputs a first current signal; a precision resistor connected to the fluxgate current sensor and through which the first current signal flows; an operational amplifier circuit that scales the first voltage signal across the precision resistor; a compensation circuit that compensates the second voltage signal output from the operational amplifier circuit into a third voltage signal; and a DSP chip that processes the third voltage signal into a second current signal.

[0006] The difference between the magnitude of the third voltage signal and the magnitude of the preset voltage signal output by the detection circuit through the operational amplifier circuit in the second degree Celsius environment is less than a preset value; the second current signal is the current signal detected by the detection circuit in the first degree Celsius environment.

[0007] In one alternative implementation, the compensation circuit includes one or more NTC temperature sensors.

[0008] In one optional implementation, the compensation circuit specifically comprises one or more NTC temperature sensors for compensating the second voltage signal output by the operational amplifier circuit into a third voltage signal.

[0009] In one alternative implementation, when the compensation circuit includes a plurality of NTC temperature sensors, each of the plurality of NTC temperature sensors is connected in parallel with each other.

[0010] In one optional implementation, the detection circuit further includes any one or more of the following:

[0011] A first power supply circuit for powering the fluxgate current sensor, a second power supply circuit for powering the operational amplifier circuit, a third power supply circuit for powering the DSP chip, and a fourth power supply circuit for powering the compensation circuit.

[0012] In one optional implementation, the first current signal and the second current signal are current signals of different magnitudes, and the first voltage signal, the second voltage signal, the third voltage signal and the preset voltage signal are voltage signals of different magnitudes.

[0013] In one optional implementation, the preset value ranges from 0.0001 to 0.00005.

[0014] In one optional implementation, the detection circuit is further configured to: acquire a third current signal from the battery detection device via the fluxgate current sensor and convert it into a first current signal before outputting the first current signal via the fluxgate current sensor.

[0015] In one alternative implementation, the second degree Celsius includes the temperature at which the resistance of the devices in the detection circuit is not distorted.

[0016] This utility model provides a current signal detection circuit, wherein the detection circuit is in an environment of a first degree Celsius, comprising:

[0017] The system comprises: a fluxgate current sensor that outputs a first current signal; a precision resistor connected to the fluxgate current sensor and through which the first current signal flows; an operational amplifier circuit that scales the first voltage signal across the precision resistor; a compensation circuit that compensates the second voltage signal output from the operational amplifier circuit into a third voltage signal; and a DSP chip that processes the third voltage signal into a second current signal.

[0018] The difference between the magnitude of the third voltage signal and the magnitude of the preset voltage signal output by the detection circuit through the operational amplifier circuit in the second degree Celsius environment is less than a preset value; the second current signal is the current signal detected by the detection circuit in the first degree Celsius environment.

[0019] By employing this invention, on the one hand, the detection circuit acquires current through a fluxgate current sensor used to collect the current signal of the battery testing device, resulting in low temperature drift; on the other hand, a compensation circuit is further adopted to compensate for the voltage signal output by the operational amplifier circuit in the detection circuit under different ambient temperatures, so as to achieve accurate measurement of the current signal of the battery testing device. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a current signal detection circuit provided by this utility model;

[0022] Figure 2 This is a schematic diagram of the connection circuit of the fluxgate current sensor in a current signal detection circuit provided by this utility model;

[0023] Figure 3 This is a schematic diagram of the operational amplifier circuit and the compensation circuit in a current signal detection circuit provided by this utility model. Detailed Implementation

[0024] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0025] It should be noted that the terms "first," "second," and "third" in this utility model are only used to distinguish different circuits, degrees Celsius, current signals, etc., and have no other meaning. They should not be used to limit the scope of protection of this utility model.

[0026] See Figure 1 This is a schematic diagram of a current signal detection circuit provided by this utility model, as shown below. Figure 1As shown, specifically, the detection circuit operates in an environment of a first degree Celsius, and the detection circuit may include, but is not limited to: a fluxgate current sensor that outputs a first current signal; a precision resistor connected to the fluxgate current sensor and flowing through the first current signal; an operational amplifier circuit that scales the first voltage signal across the precision resistor; a compensation circuit that compensates the second voltage signal output by the operational amplifier circuit into a third voltage signal; and a DSP (Digital Signal Processor) chip that processes the third voltage signal into a second current signal. The difference between the magnitude of the third voltage signal and the magnitude of the preset voltage signal output by the detection circuit through the operational amplifier circuit in the second degree Celsius environment is less than a preset value. The second current signal serves as the current signal detected by the detection circuit in the first degree Celsius environment. The precision resistor may be an electronic component with superior resistance error, temperature coefficient, and stability compared to ordinary resistors.

[0027] It should be noted that the DSP chip can process the third voltage signal into a second current signal through calculation.

[0028] Preferably, at the first moment, the difference between the magnitude of the third voltage signal and the magnitude of the preset voltage signal output by the detection circuit through the operational amplifier circuit in the second degree Celsius environment is less than a preset value, wherein the first moment is any moment in the first degree Celsius environment, and the temperature range of the first degree Celsius can be between -30 degrees Celsius and 140 degrees Celsius.

[0029] Preferably, the values ​​of the second and third voltage signals include ADC (Analog-Digital Converter) signal values;

[0030] Preferably, the second degree Celsius can be the temperature at which the resistance values ​​of the devices in the detection circuit are not distorted, that is, the temperature at which the resistance values ​​of the fluxgate current sensor, precision resistor, operational amplifier circuit, and other devices in the detection circuit are not distorted. In other words, the second degree Celsius can be a conventional temperature, such as 25 degrees Celsius. The first degree Celsius can be any temperature, such as 50 degrees Celsius, and this invention is not limited thereto.

[0031] More specifically, the compensation circuit may include, but is not limited to, one or more NTC temperature sensors.

[0032] Optionally, the compensation circuit may specifically be one or more NTC (Negative Temperature Coefficient) temperature sensors used to compensate the second voltage signal output by the operational amplifier circuit into a third voltage signal.

[0033] When the compensation circuit includes multiple NTC temperature sensors, each of the multiple NTC temperature sensors is connected in parallel. For example, when the compensation circuit includes a first NTC temperature sensor and a second NTC temperature sensor, the first NTC temperature sensor and the second NTC temperature sensor are connected in parallel. For example, in addition to the first and second NTC temperature sensors, the compensation circuit may also include a third NTC temperature sensor, wherein the first, second, and third NTC temperature sensors are connected in parallel.

[0034] It should be noted, for example, that due to the decrease in internal resistance of related components such as fluxgate current sensors, precision resistors, and operational amplifier circuits as their own temperature and the ambient temperature increase, the second voltage signal output by the operational amplifier circuit becomes larger. In this invention, an NTC temperature sensor or a compensation circuit including one or more NTC temperature sensors is used to compensate for the second voltage signal. That is, when the temperature of the NTC temperature sensor itself and the ambient temperature increase, the resistance value of the NTC temperature sensor decreases, thereby affecting the scaling factor of the operational amplifier circuit, which in turn causes the second voltage signal output by the operational amplifier circuit to become smaller, ultimately obtaining a compensated third voltage signal.

[0035] Therefore, by using this invention, the second voltage signal output by the operational amplifier circuit can be compensated into a third voltage signal by employing a supplementary circuit containing an NTC temperature sensor, thus enabling accurate measurement of the current signal of the battery detection device.

[0036] Preferably, the compensation circuit is integrated into the operational amplifier circuit; or the compensation circuit is integrated into the detection circuit and is separate from the operational amplifier circuit. When the compensation circuit is integrated into the detection circuit, the supplementary circuit is also connected to the operational amplifier circuit.

[0037] Preferably, the preset value ranges from 0.0001 to 0.00005, that is, the preset value can be any value from the range of 0.0001 to 0.00005;

[0038] It should be noted that the detection circuit is also used to: acquire the third current signal of the battery detection device through the fluxgate current sensor before outputting the first current signal through the fluxgate current sensor, and convert it into the first current signal.

[0039] It should be noted that the first current signal and the second current signal are current signals of different magnitudes, and the first voltage signal, the second voltage signal, the third voltage signal and the preset voltage signal are voltage signals of different magnitudes.

[0040] It should be noted that, in addition to the fluxgate current sensor, precision resistor, operational amplifier circuit, compensation circuit, and DSP chip, the detection circuit may also include, but is not limited to, any one or more of the following:

[0041] A first power supply circuit for powering the fluxgate current sensor, a second power supply circuit for powering the operational amplifier circuit, a third power supply circuit for powering the DSP chip, and a fourth power supply circuit for powering the compensation circuit.

[0042] The fluxgate current sensor is connected to a first power supply circuit, the operational amplifier circuit is connected to a second power supply circuit that supplies power to the operational amplifier circuit, the DSP chip is connected to a third power supply circuit that supplies power to the DSP chip, and the compensation circuit is connected to a fourth power supply circuit that supplies power to the compensation circuit.

[0043] The first power supply circuit can be a 15V power supply.

[0044] Figure 2 An exemplary diagram illustrates the connection circuit of a fluxgate current sensor in a current signal detection circuit, as shown below. Figure 2 As shown,

[0045] The first power supply circuit can be a 15V power supply; the output interface of the fluxgate current sensor is based on a differential signal line connected to a precision resistor, and then connected to the operational amplifier circuit and the compensation circuit through the I1+ and I1- terminals of the differential signal line.

[0046] Figure 3 An exemplary diagram illustrates the operational amplifier circuit and compensation link in a current signal detection circuit, specifically as follows: Figure 3 As shown, the first interface of the operational amplifier circuit is connected to the fluxgate current sensor via the I1+ and I1- terminals of the differential signal line. The second interface of the operational amplifier circuit is connected to the compensation circuit, and the third interface of the operational amplifier circuit is connected to the DSP chip. The compensation circuit may include, but is not limited to, RT1, RT2, and RT3; RT1, RT2, and RT3 are connected in parallel, and RT1, RT2, and RT3 may represent three NTC temperature sensors of the same model.

[0047] Figure 1-3 This is merely used to explain the embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0048] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A detection circuit of a current signal, the detection circuit being in an environment of a first degree Celsius, characterized in that, include: The system comprises: a fluxgate current sensor that outputs a first current signal; a precision resistor connected to the fluxgate current sensor and through which the first current signal flows; an operational amplifier circuit that scales the first voltage signal across the precision resistor; a compensation circuit that compensates the second voltage signal output from the operational amplifier circuit into a third voltage signal; and a DSP chip that processes the third voltage signal into a second current signal. The difference between the magnitude of the third voltage signal and the magnitude of the preset voltage signal output by the detection circuit through the operational amplifier circuit in the second degree Celsius environment is less than a preset value; the second current signal is the current signal detected by the detection circuit in the first degree Celsius environment.

2. The current signal detection circuit as described in claim 1, characterized in that, The compensation circuit includes one or more NTC temperature sensors.

3. The current signal detection circuit as described in claim 1 or 2, characterized in that, The compensation circuit specifically comprises one or more NTC temperature sensors used to compensate the second voltage signal output by the operational amplifier circuit into a third voltage signal.

4. The current signal detection circuit as described in claim 2, characterized in that, When the compensation circuit includes multiple NTC temperature sensors, each of the multiple NTC temperature sensors is connected in parallel with each other.

5. The current signal detection circuit as described in claim 2, characterized in that, The compensation circuit is integrated into the operational amplifier circuit; or the compensation circuit is independent of the operational amplifier circuit.

6. The current signal detection circuit as described in claim 1, characterized in that, The detection circuit further includes any one or more of the following: A first power supply circuit for powering the fluxgate current sensor, a second power supply circuit for powering the operational amplifier circuit, a third power supply circuit for powering the DSP chip, and a fourth power supply circuit for powering the compensation circuit.

7. The current signal detection circuit as described in claim 1, characterized in that, The first current signal and the second current signal are current signals of different magnitudes, and the first voltage signal, the second voltage signal, the third voltage signal and the preset voltage signal are voltage signals of different magnitudes.

8. The current signal detection circuit as described in claim 1, characterized in that, The preset value range is 0.0001 to 0.00005.

9. The current signal detection circuit as described in claim 1, characterized in that, The second degree Celsius includes the temperature at which the resistance value of the devices in the detection circuit is not distorted.

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