Current detection circuit

Abstract

The utility model discloses a current detection circuit. Comprising a DC / DC converter, a charge pump voltage reverser, a current sensing amplifier and a single-chip microcomputer. An analog-to-digital converter is arranged in the single chip microcomputer; the input end of the DC / DC converter is connected with the output positive electrode of an external DC power supply, and the output end is connected with the input end of the charge pump voltage reverser; the output anode of the external DC power supply is connected with the power end of the load. The in-phase input end of the current sensing amplifier is connected with the sampling end of the load; the sampling end of the load is connected with the return cathode of the external direct-current power supply through a resistor R16; the inverted input end of the current sensing amplifier is connected with the return cathode of the external DC power supply, and the output end is connected with the input end of the single-chip microcomputer. The grounding end of the current sensing amplifier is connected with the output end of the charge pump voltage reverser. According to the invention, 120V or higher voltage can be detected, the measured total consumption current comprises the power consumption of the detection circuit, and the limitation of the traditional high-side and low-side detection circuits is broken through.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and in particular to a current detection circuit. Background Art

[0002] Intelligent stratified water injection is a common production enhancement technology in the oil industry. In this process, it is very important to test the accuracy and stability of the power consumption of the equipment, because it can improve the accuracy of data recording and problem diagnosis capabilities. Detecting current is an effective means of evaluating the power consumption of equipment, because there is a direct correlation between power consumption and current. By measuring the current, you can understand the amount of electrical energy consumed by the equipment during operation, and thus infer its power consumption level.

[0003] There are two traditional ways to detect DC current, including:

[0004] (1) High-side current detection: Figure 1 As shown, in high-side current detection, a resistor is connected in series with the high-voltage DC power line, and the current signal is converted into a voltage signal through resistor voltage division, and then amplified by the amplifier and sampled to the microcontroller for processing. The advantage of this method is that the circuit structure is relatively simple and the current value can be measured more accurately. However, its disadvantage is that the input voltage of the amplifier is limited, and the DC voltage above the input voltage of the amplifier chip cannot be tested. At present, no amplifier chip that can withstand an input voltage higher than 120V has been found; if such an amplifier chip exists, its price will also be very expensive and the number will be scarce. In other words, when the detected voltage exceeds 120V, the high-side current detection circuit cannot achieve detection.

[0005] (2) Low-side current detection: Figure 2 As shown in the figure, the low-side current detection is to connect a resistor in series with the GND line, and also convert the current signal into a voltage signal through the resistor voltage divider, and then sample it through the amplifier to the microcontroller for processing. The advantage of this method is that it can avoid the input voltage limitation of the amplifier, but its disadvantage is that the power consumption of the amplifier itself, the subsequent ADC chip and the microcontroller (detection circuit) is not included in the detection circuit.

[0006] The above two existing methods of detecting DC current have certain limitations and cannot fully meet the needs of power consumption testing of intelligent stratified water injection equipment. Utility Model Content

[0007] To this end, the present application provides a current detection circuit, which aims to avoid the input voltage limitation of the amplifier and obtain the entire power consumption of the load and the detection circuit itself.

[0008] In order to achieve the above objectives, this application provides the following technical solutions:

[0009] A current detection circuit includes a DC / DC converter, a charge pump voltage inverter, a current sensing amplifier and a single chip microcomputer; the single chip microcomputer has a built-in analog-to-digital converter;

[0010] The input end of the DC / DC converter is connected to the output positive pole of the external DC power supply, the output end of the DC / DC converter is connected to the input end of the charge pump voltage inverter, and the output end of the charge pump voltage inverter is used to output a negative voltage; the output positive pole of the external DC power supply is connected to the power supply end of the load; the non-inverting input end of the current sensing amplifier is connected to the sampling end of the load; the sampling end of the load is also connected to the return negative pole of the external DC power supply through a resistor R16; the inverting input end of the current sensing amplifier is connected to the return negative pole of the external DC power supply, and the output end of the current sensing amplifier is connected to the input end of the single-chip microcomputer; the power supply end of the current sensing amplifier and the power supply end of the single-chip microcomputer are both connected to the output end of the DC / DC converter, the ground end of the current sensing amplifier is connected to the output end of the charge pump voltage inverter, and the reference voltage end of the current sensing amplifier is connected to the reference ground end.

[0011] Optionally, the sampling terminal of the load is also connected to a reference ground terminal.

[0012] Optionally, the load is a power-consuming peripheral device in the intelligent stratified water injection equipment.

[0013] Optionally, a model of the current sensing amplifier is INA199A1DCKR.

[0014] Optionally, the resistance of the resistor R16 is 0.1Ω.

[0015] Compared with the prior art, this application has at least the following beneficial effects:

[0016] The embodiment of the present application provides a new hardware architecture of a current detection circuit, which is based on a traditional low-voltage side detection circuit, with an additional charge pump voltage inverter, and a current sensing amplifier is used to replace the amplifier. At the same time, the in-phase input terminal of the current sensing amplifier is connected to the sampling terminal of the load, and the sampling terminal of the load is connected to the return negative electrode of the external DC power supply through a resistor R16, and the inverting input terminal of the current sensing amplifier is connected to the return negative electrode of the external DC power supply; the total current provided by the external power supply to the entire current detection circuit can be measured through the current sensing amplifier, that is, the total current consumed by the load, the current sensing amplifier and the single-chip microcomputer included in the current detection circuit can be measured; due to the introduction of negative voltage on the low-voltage side, the voltage of the detected part can be reduced to below 0V, and devices powered by extremely high DC voltage can be tested, for example, the detected voltage can exceed 120V; therefore, the current detection circuit provided by the present application can avoid the input voltage limitation of the amplifier, and at the same time, the full power consumption of the load and the detection circuit itself can be obtained, breaking through the limitations of traditional high-side and low-side detection circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more intuitively illustrate the prior art and the present application, exemplary drawings are given below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing the present application; for example, those skilled in the art are capable of easily making conventional adjustments or further optimizations to the addition / reduction / attribution division, specific shapes, positional relationships, connection methods, dimensional ratios, etc. of certain units (components) based on the technical concepts and exemplary drawings disclosed in the present application.

[0018] Figure 1 is the schematic diagram of the traditional high-side current detection circuit;

[0019] Figure 2 It is the schematic diagram of the traditional low-side current detection circuit;

[0020] Figure 3 A schematic diagram of a current detection circuit provided in Embodiment 1 of the present application;

[0021] Figure 4 This is a pin diagram of the current sensing amplifier in the first embodiment of the present application;

[0022] Figure 5 This is an internal functional diagram of the current sensing amplifier in the first embodiment of the present application;

[0023] Figure 6 A schematic diagram of another current detection circuit provided in Example 2 of the present application.

[0024] Description of reference numerals:

[0025] 101. DC / DC converter; 102. Charge pump voltage inverter; 103. Current sensing amplifier; 104. Microcontroller; 105. Load; 106. Amplifier; 107. Analog-to-digital converter. DETAILED DESCRIPTION

[0026] The present application is further described below in detail through specific embodiments in conjunction with the accompanying drawings.

[0027] In the description of the present application: unless otherwise specified, expressions such as “include”, “comprising”, “having”, etc. also mean “not limited to” (certain units, components, materials, steps, etc.).

[0028] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in this application are usually used to indicate the general relative position relationship for the purpose of intuitive understanding by referring to the drawings, and are not absolute limitations on the position relationship in the actual product.

[0029] Embodiment 1

[0030] In this embodiment, if Figure 3 As shown, a current detection circuit is provided, which includes a DC / DC converter 101, a charge pump voltage inverter 102, a current sensing amplifier 103 and a single-chip microcomputer 104; the selected single-chip microcomputer 104 has a built-in analog-to-digital converter;

[0031] Specifically, the input end of the DC / DC converter 101 is connected to the output positive pole of the external DC power supply (i.e., 120V), the output end of the DC / DC converter 101 is connected to the input end of the charge pump voltage inverter 102, and the output end of the charge pump voltage inverter 102 is used to output a negative voltage (i.e., -5V); the output positive pole of the external DC power supply is connected to the power supply end of the load 105; the in-phase input end (i.e., pin 4 IN+) of the current sensing amplifier 103 is connected to the sampling end of the load 105; the sampling end of the load 105 is also connected to the return negative pole of the external DC power supply (DC power supply return line, i.e., 120V_Re) through the resistor R16. turn); the inverting input terminal (i.e., pin 5 IN+) of the current sensing amplifier 103 is connected to the return negative pole of the external DC power supply, and the output terminal (i.e., pin 6 OUT) of the current sensing amplifier 103 is connected to the input terminal of the single-chip computer 104; the power supply terminal (i.e., pin 3 V+) of the current sensing amplifier 103 and the power supply terminal of the single-chip computer 104 are both connected to the output terminal of the DC / DC converter 101, the ground terminal (i.e., pin 2 GND) of the current sensing amplifier 103 is connected to the output terminal of the charge pump voltage inverter 102, and the reference voltage terminal (i.e., pin 1 REF) of the current sensing amplifier 103 is connected to the reference ground terminal.

[0032] In addition, the sampling terminal of the load 105 and the ground terminal of the single chip computer 104 are both connected to the reference ground terminal.

[0033] The load 105 is specifically a power-consuming peripheral device in the intelligent stratified water injection equipment.

[0034] There are many peripheral circuits (i.e., peripherals) in the intelligent stratified water injection equipment, such as motors, drive circuits, various sensors, etc. These peripheral circuits constitute the downhole circuit or the above-hole circuit of the intelligent stratified water injection equipment; the load 105 in the embodiment of the present application refers to the power-consuming peripherals of the various parts of the downhole circuit board or the above-hole circuit board of the intelligent stratified water injection equipment, that is, the power-consuming part of the circuit board.

[0035] When the current detection circuit provided in the present application is used for an above-ground circuit board, the load 105 may include peripherals such as a storage chip, a communication chip, and a drive circuit; when the current detection circuit provided in the present application is used for an underground circuit board, the load 105 may include peripherals such as a motor, a storage chip, a communication chip, and a drive circuit.

[0036] Compared with the traditional DC current detection circuit, the current detection circuit provided in this embodiment does not use an amplifier, but uses a current sensing amplifier 103. Compared with the traditional DC current detection circuit, the overall circuit structure is simpler.

[0037] The current sensing amplifier 103 may use a product of the INA199A1DCKR type, but is not limited to this type of chip. The pin diagram and internal function diagram of the INA199A1DCKR type current sensing amplifier 103 are shown in FIG. Figure 4 and Figure 5 As shown, the chip pin 2 is marked as GND. In this embodiment, this GND is connected to the negative power supply, because the chip input and output are relative to GND. Lowering GND only reduces the internal reference level and ensures that the difference between V+ and GND is within the chip's allowable range. Connecting the GND of the current sensing amplifier 103 to a negative voltage can reduce the voltage detected by the current sensing amplifier 103 to below 0V. Then, through the 1-pin REF, the output can be increased to above 0V, and the OUT pin can be directly output to the pin of the microcontroller with ADC, saving the cost of an independent ADC chip.

[0038] Figure 3 is a functional diagram of using the current sensing amplifier 103, in Figure 3 In the example, the external inputs are 120V and 120V_Return. The load driven by the circuit board and the power consumption of all internal chips will pass through the sampling resistor R16, so a more accurate overall power consumption current can be measured. Note that the resistance of resistor R16 is only 0.1Ω, and the loss is very small.

[0039] Of course, the resistance value of the resistor R16 can be determined according to the sampling range and accuracy of the current sensing amplifier 103 .

[0040] Based on the hardware architecture provided in the embodiment of the present application, the current between the output positive pole and the return negative pole of the external power supply can be measured by using the current sensing amplifier 103, which is equivalent to measuring the total current provided by the external power supply for the entire current detection circuit. Because the resistance of the sampling resistor R16 is only 0.1 ohms, and the input resistance inside the current sensing amplifier 103 is above 1M ohms, most of the current in the current detection circuit will be sampled through the sampling resistor R16. Therefore, the current measured by the current sensing amplifier 103 is the total current that includes the power consumption of the load 105, the current sensing amplifier 103 and the single-chip computer 104.

[0041] It can also be said that the current detected by the current detection circuit includes the total power consumption of the peripherals of each part of the circuit board. If the circuit is used for the above-ground circuit board, it includes the total power consumption of peripherals such as memory chips, communication chips, drive circuits, etc.; if the circuit is used for the underground circuit board, it includes the total power consumption of peripherals such as motors, memory chips, communication chips, drive circuits, etc.

[0042] The embodiment of the present application provides a new hardware architecture of a current detection circuit, which is based on a traditional low-voltage side detection circuit, with an additional charge pump voltage inverter, and a current sensing amplifier is used instead of an amplifier. At the same time, the non-inverting input terminal of the current sensing amplifier is connected to the sampling terminal of the load, the sampling terminal of the load is connected to the return negative electrode of the external DC power supply through a resistor R16, and the inverting input terminal of the current sensing amplifier is connected to the return negative electrode of the external DC power supply; the total current provided by the external power supply to the entire current detection circuit can be measured through the current sensing amplifier, that is, the total current consumed by the load, the current sensing amplifier and the microcontroller in the current detection circuit can be measured.

[0043] In the current detection circuit provided in the embodiment of the present application, a negative voltage is introduced into the current sensing amplifier by connecting the output end of the charge pump voltage inverter to the ground end of the current sensing amplifier. By introducing a negative voltage on the low voltage side, the voltage of the detected part can be reduced to below 0V, and devices powered by extremely high DC voltages can be tested, such as loads above 120V DC voltage. In addition, the current detection circuit can test the total power consumption including the load and the detection circuit, and the overall power consumption can be detected more accurately.

[0044] Traditional high-side current detection circuits cannot test DC voltages above the chip supply voltage. For example, if the amplifier supply voltage is 32V, the highest level of the input amplifier pin cannot exceed 32V. Traditional low-side current detection can solve the problem of testing the current size of the load, but does not include the power consumption of the detection chip itself. This technical improvement can obtain the full power consumption of the load and the detection chip itself, and the detected voltage can exceed 120V.

[0045] In other words, the current detection circuit provided by the embodiment of the present application can be used in extremely high DC voltage systems, and at the same time measures the total current consumption of the entire system, especially the power consumption of the chip related to the detection current, breaking through the limitations of traditional high-side and low-side detection circuits. The current detection circuit can detect 120V or higher voltage, and at the same time includes the total current consumed by all devices such as internal amplifiers, ADCs, and single-chip microcomputers.

[0046] In addition, the current detection circuit provided in the embodiment of the present application simplifies the circuit design and saves costs by improving the power supply design of the current sensing amplifier. It breaks through the description limitation of GND in the manual of the current sensing amplifier and introduces negative voltage to expand the detection range. At the same time, the measured current includes the power consumption of the components used for detection.

[0047] Embodiment 2

[0048] In this embodiment, if Figure 6 As shown, another current detection circuit is provided, which includes a DC / DC converter 101, a charge pump voltage inverter 102, an amplifier 106, an analog-to-digital converter (i.e., ADC) 107 and a single-chip microcomputer 104;

[0049] Specifically, the input end of the DC / DC converter 101 is connected to the output positive electrode (i.e., Power) of the external DC power supply, the output end of the DC / DC converter 101 is connected to the input end of the charge pump voltage inverter 102, and the output end of the charge pump voltage inverter 102 is used to output a negative voltage (i.e., -VCC); the output positive electrode of the external DC power supply is connected to the power supply end of the load 105; the in-phase input end (i.e., pin 3) of the amplifier 106 is connected to the sampling end of the load 105 through a resistor R11; the sampling end of the load 105 is also connected to the return negative electrode (i.e., Power_return) of the external DC power supply through a resistor R13; the in-phase input end of the amplifier 106 is also connected to the reference ground end through a resistor R12; The inverting input terminal (i.e., pin 2) of the amplifier 106 is connected to the negative return electrode of the external DC power supply through the resistor R14, and the output terminal (i.e., pin 1) of the amplifier 106 is connected to the input terminal of the analog-to-digital converter 107; the output terminal of the analog-to-digital converter 107 is connected to the input terminal of the single-chip computer 104; the output terminal of the amplifier 106 is also connected to the negative return electrode of the external DC power supply through the resistor R15 and the resistor R14; the positive power terminal (i.e., pin 8) of the amplifier 106, the power terminal of the analog-to-digital converter 107 and the power terminal of the single-chip computer 104 are all connected to the output terminal of the DC / DC converter 101; the negative power terminal (i.e., pin 4) of the amplifier 106 and the ground terminal of the analog-to-digital converter 107 are all connected to the output terminal of the charge pump voltage inverter 102.

[0050] In addition, the sampling terminal of the load 105 and the ground terminal of the single chip computer 104 are both connected to the reference ground terminal.

[0051] The load 105 is specifically a power-consuming peripheral device in the intelligent stratified water injection equipment.

[0052] There are many peripheral circuits (i.e., peripherals) in the intelligent stratified water injection equipment, such as motors, drive circuits, various sensors, etc. These peripheral circuits constitute the downhole circuit or the above-hole circuit of the intelligent stratified water injection equipment; the load 105 in the embodiment of the present application refers to the power-consuming peripherals of the various parts of the downhole circuit board or the above-hole circuit board of the intelligent stratified water injection equipment, that is, the power-consuming part of the circuit board.

[0053] When the current detection circuit provided in the present application is used for an above-ground circuit board, the load 105 may include peripherals such as a storage chip, a communication chip, and a drive circuit; when the current detection circuit provided in the present application is used for an underground circuit board, the load 105 may include peripherals such as a motor, a storage chip, a communication chip, and a drive circuit.

[0054] The resistance value of each resistor in the current detection circuit can be determined according to actual conditions.

[0055] The embodiment of the present application provides a new hardware architecture of a current detection circuit, which is based on a traditional low-voltage side detection circuit and adds a charge pump voltage inverter. At the same time, the in-phase input terminal of the amplifier is connected to the sampling terminal of the load through a resistor R11, the sampling terminal of the load is connected to the return negative electrode of the external DC power supply through a resistor R13, and the inverting input terminal of the amplifier is connected to the return negative electrode of the external DC power supply through a resistor R14; the total current provided by the external power supply to the entire current detection circuit can be measured through the amplifier, that is, the total current consumed by the load, amplifier, ADC and microcontroller in the current detection circuit can be measured.

[0056] In the current detection circuit provided in the embodiment of the present application, by connecting the output end of the charge pump voltage inverter to the negative power supply end of the amplifier and the ground end of the analog-to-digital converter, a negative voltage is introduced to the amplifier and the analog-to-digital converter, and a negative voltage is introduced on the low-voltage side, so that the voltage of the detected part can be reduced to below 0V, and devices powered by extremely high DC voltages can be tested, such as loads above 120V DC voltage. In addition, the current detection circuit can test the total power consumption including the load and the detection circuit, and the overall power consumption can be detected more accurately.

[0057] Traditional high-side current detection circuits cannot test DC voltages above the chip supply voltage. For example, if the amplifier supply voltage is 32V, the highest level of the input amplifier pin cannot exceed 32V. Traditional low-side current detection can solve the problem of testing the current size of the load, but does not include the power consumption of the detection chip itself. This technical improvement can obtain the full power consumption of the load and the detection chip itself, and the detected voltage can exceed 120V.

[0058] In other words, the current detection circuit provided by the embodiment of the present application can be used in extremely high DC voltage systems, and at the same time measures the total current consumption of the entire system, especially the power consumption of the chip related to the detection current, breaking through the limitations of traditional high-side and low-side detection circuits. The current detection circuit can detect 120V or higher voltage, and at the same time includes the total current consumed by all detection devices such as internal amplifiers, ADCs, and single-chip microcomputers.

[0059] The technical features of the above embodiments may be arbitrarily combined (as long as there is no contradiction in the combination of these technical features). To make the description concise, not all possible combinations of the technical features in the above embodiments are described; these embodiments that are not explicitly written should also be considered to be within the scope of this specification.

Claims

1. A current detection circuit, characterized in that: It includes a DC / DC converter, a charge pump voltage inverter, a current sensing amplifier and a single chip microcomputer; the single chip microcomputer has a built-in analog-to-digital converter; The input end of the DC / DC converter is connected to the output positive pole of the external DC power supply, the output end of the DC / DC converter is connected to the input end of the charge pump voltage inverter, and the output end of the charge pump voltage inverter is used to output a negative voltage; the output positive pole of the external DC power supply is connected to the power supply end of the load; the non-inverting input end of the current sensing amplifier is connected to the sampling end of the load; the sampling end of the load is also connected to the return negative pole of the external DC power supply through a resistor R16; the inverting input end of the current sensing amplifier is connected to the return negative pole of the external DC power supply, and the output end of the current sensing amplifier is connected to the input end of the single-chip microcomputer; the power supply end of the current sensing amplifier and the power supply end of the single-chip microcomputer are both connected to the output end of the DC / DC converter, the ground end of the current sensing amplifier is connected to the output end of the charge pump voltage inverter, and the reference voltage end of the current sensing amplifier is connected to the reference ground end.

2. The current detection circuit according to claim 1, characterized in that: The sampling terminal of the load is also connected to the reference ground terminal.

3. The current detection circuit according to claim 1, characterized in that: The load is a power-consuming peripheral device in the intelligent stratified water injection equipment.

4. The current detection circuit according to claim 1, characterized in that: The model of the current sensing amplifier is INA199A1DCKR.

5. The current detection circuit according to claim 1, characterized in that: The resistance value of the resistor R16 is 0.1Ω.

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