CN212540524U - Current measurement circuit and equipment applying same - Google Patents
Current measurement circuit and equipment applying same Download PDFInfo
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- CN212540524U CN212540524U CN202022197696.5U CN202022197696U CN212540524U CN 212540524 U CN212540524 U CN 212540524U CN 202022197696 U CN202022197696 U CN 202022197696U CN 212540524 U CN212540524 U CN 212540524U
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Abstract
The utility model provides a current measurement circuit and applied this circuit's equipment, current measurement circuit includes detection module, analog-to-digital converter and processing module, detection module is used for converting the sampling current of input into sampling voltage signal, analog-to-digital converter is used for comparing the sampling voltage signal of input and reference fixed voltage, outputs digital signal, processing module be used for with digital signal and standard value calculation are compared to obtain measuring result.
Description
Technical Field
The utility model relates to an information electronics technical field especially relates to an equipment of current measurement circuit and applied this circuit.
Background
The current detection technology has extremely wide application, and the current flowing in and out needs to be detected in many systems. Such as current protection/monitoring devices, 4-20mA current loop systems, programmable current sources, linear/switch mode power supplies, and chargers or fuel gauges that require knowledge of the ratio of the incoming and outgoing currents.
The existing current detection technology generally adopts a transition transfer method, wherein the transition transfer method is to measure a resistor according to a voltammetry principle so as to obtain a current value, specifically, a shunt is connected into a circuit, the voltage at two ends of the shunt is measured, and then the measured voltage is divided by the resistance value of the shunt according to an ohm law so as to obtain the current value in the circuit.
In the current detection scheme of the transition transfer method, a discrete or semi-discrete element circuit is generally adopted, and since the electric power consumed by the current on the resistor of the current divider is converted into heating energy, the resistance value of the circuit is changed, the phase of the voltage at two ends relative to the phase of the current is out of phase, and additional phase shift is generated.
Disclosure of Invention
The utility model provides a device of current measurement circuit and applied this circuit, through sampling simultaneously to being surveyed signal and reference fixed voltage, processing module handles two signals simultaneously, therefore has eliminated test current error and drift and to measuring result's influence, has improved the measuring degree of accuracy.
In one aspect, the utility model provides a current measurement circuit, this circuit include detection module, analog-to-digital converter and processing module, detection module is used for converting the sampling current of input into sampling voltage signal, analog-to-digital converter is used for comparing the sampling voltage signal of input and reference fixed voltage, outputs digital signal, processing module be used for with digital signal and standard value calculation are compared to obtain measuring result.
The measured signal and the reference fixed voltage (standard signal) are sampled simultaneously, and the processing module processes the two signals simultaneously, so that the influence of the error and the drift of the test current on the measurement result is eliminated, and the measurement accuracy is improved.
In one possible embodiment of the current measuring circuit, the measurement result is a current value obtained from detection by the current measuring circuit.
In a possible implementation manner of the current measurement circuit, the analog-to-digital converter specifically includes an integrated operational amplifier, two input ends of the integrated operational amplifier are respectively a first input end and a second input end, the sampling voltage signal obtained by the detection module is input through the first input end, and the reference fixed voltage is input through the second input end. The integrated operational amplifier outputs a digital signal by comparing the input sampling voltage signal with the reference fixed voltage, thereby converting the sampling voltage signal into a digital signal.
The integrated operational amplifier samples the sampling voltage signal and the reference fixed voltage signal at the same time and carries out operational amplifier comparison processing. That is, an analog voltage signal is compared with a reference fixed voltage, and at a value around the same amplitude, the output voltage will make a transition, and correspondingly output a high level or a low level, thereby converting the analog signal of the sampling voltage signal into a digital signal.
In a possible embodiment of the current measurement circuit, the analog-to-digital converter may further include a plurality of integrated operational amplifiers, which are arranged in series. In particular, the analog-to-digital converter may include a first integrated operational amplifier and a second integrated operational amplifier.
The sampling voltage signal obtained by the detection module is input into one input end of the first integrated operational amplifier, and a signal output by the output end of the first integrated operational amplifier is input into the other input end of the first integrated operational amplifier. The signal output by the output end of the first integrated operational amplifier is input into one input end of the second integrated operational amplifier, and the reference fixed voltage is input into the other input end of the second integrated operational amplifier.
The first integrated operational amplifier and the second integrated operational amplifier are adopted to realize the two operational amplifier circuits, so that the double ADC samples the tested signal and the reference fixed voltage (standard signal) at the same time, and the processing module processes the two signals at the same time, thereby further eliminating the influence of the test current error and the drift on the measurement result and improving the accuracy of measurement.
In one possible embodiment of the current measuring circuit, the sampling current may be a direct current excitation current.
In one possible embodiment of the current measuring circuit, the processing module may be a single chip. The processing module can also be a signal processing system of a single chip microcomputer.
In one possible embodiment of the current measuring circuit, the analog-to-digital converter and the processing module may be integrated.
In a possible implementation manner of the current measuring circuit, the current measuring circuit may further include a current divider, and the current divider is configured to sample a current to be measured and output a sampled current obtained by sampling to the detection module.
In a second aspect, the present invention further provides an apparatus using a current measuring circuit, the apparatus including a detected circuit, the current measuring circuit and a control circuit, the current measuring circuit is used for detecting a current in the detected circuit, and the control circuit is used for controlling the detected circuit according to a measurement result of the current measuring circuit.
In one possible embodiment of the device, the electronic device may be a power supply device.
In one possible embodiment of the device, the detected circuit may be a motor.
Drawings
Fig. 1 is a schematic diagram of components of an embodiment of a current measurement circuit of the present invention;
fig. 2 is a schematic circuit diagram of an embodiment of the current measuring circuit of the present invention; and
fig. 3 is a schematic component diagram of an embodiment of an electronic device according to the present invention.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
First, some terms in the present invention are explained so as to be easily understood by those skilled in the art.
ADC: is called Analog-to-digital converter, and the translation into Chinese is: analog-to-digital converters, also referred to as analog-to-digital converters, are a class of devices used to convert continuous signals in analog form to discrete signals in digital form. An analog to digital converter may provide the signal for measurement. The device opposite to the analog-to-digital converter is called a digital-to-analog converter. A typical analog-to-digital converter can convert an analog signal to a digital signal representing a proportional voltage value.
A single chip microcomputer: the singlechip is an integrated circuit chip, which is a small and perfect microcomputer system formed by integrating functions (possibly including a display drive circuit, a pulse width modulation circuit, an analog multiplexer, an A/D converter and other circuits) of a Central Processing Unit (CPU), a Random Access Memory (RAM), a read-only memory (ROM), various input/output (I/O) ports, an interrupt system, a timer/counter and the like with data processing capacity on a silicon chip by adopting a super-large scale integrated circuit technology, and the singlechip is widely applied to the field of industrial control.
Exciting current: in english, Exciting Current is the Current flowing through the rotor of the synchronous motor (with this Current, the rotor is equivalent to an electromagnet, and has N and S poles). Conventionally, this dc voltage is supplied from a dc motor, and is currently supplied by rectifying it with a thyristor in most cases.
In the embodiment of the utility model, change the measurement of the resistance ratio in traditional transition transfer method into the measurement of potential ratio, change the resistance measurement of voltammetry principle into the ratio measurement method.
Current measuring circuit
As shown in fig. 1 and fig. 2, the embodiment of the utility model provides a current measurement circuit, this circuit includes detection module, analog-to-digital converter and processing module, detection module is used for converting the sampling current of input into sampling voltage signal, analog-to-digital converter is used for comparing the sampling voltage signal of input and reference fixed voltage, outputs digital signal, processing module is used for with digital signal and standard value calculation compare to obtain measuring result.
The utility model discloses an in the embodiment of current measurement circuit, through sampling simultaneously to measured signal and reference fixed voltage (standard signal), processing module handles two signals simultaneously, therefore has eliminated test current error and drift and to measuring result's influence, has improved the measuring degree of accuracy.
In an embodiment of the current measuring circuit of the present invention, the measurement result is a current value obtained according to the detection of the current measuring circuit.
The utility model discloses an in the embodiment of current measurement circuit, if the sampling current of input detection module is weak current, then detection module will weak sampling current converts weak voltage signal into.
In fig. 2, the circuitry within the dashed box is the circuitry of one embodiment of the detection module.
As shown in fig. 2, in the embodiment of the current measuring circuit of the present invention, the analog-to-digital converter specifically includes an integrated operational amplifier, two inputs of the integrated operational amplifier are respectively a first input terminal and a second input terminal, through the first input terminal inputs the sampling voltage signal obtained by the detecting module, through the second input terminal inputs the reference fixed voltage. The integrated operational amplifier outputs a digital signal by comparing the input sampling voltage signal with the reference fixed voltage, thereby converting the sampling voltage signal into a digital signal.
The integrated operational amplifier samples the sampling voltage signal and the reference fixed voltage signal at the same time and carries out operational amplifier comparison processing. That is, an analog voltage signal is compared with a reference fixed voltage, and at a value around the same amplitude, the output voltage will make a transition, and correspondingly output a high level or a low level, thereby converting the analog signal of the sampling voltage signal into a digital signal.
In an embodiment of the current measuring circuit of the present invention, the analog-to-digital converter may further include a plurality of integrated operational amplifiers, and the plurality of integrated operational amplifiers are connected in series. In particular, the analog-to-digital converter may include a first integrated operational amplifier and a second integrated operational amplifier.
The sampling voltage signal obtained by the detection module is input into one input end of the first integrated operational amplifier, and a signal output by the output end of the first integrated operational amplifier is input into the other input end of the first integrated operational amplifier. The signal output by the output end of the first integrated operational amplifier is input into one input end of the second integrated operational amplifier, and the reference fixed voltage is input into the other input end of the second integrated operational amplifier.
The amplifier on the left in fig. 2 is a specific implementation of the first integrated operational amplifier and the amplifier on the right in fig. 2 is a specific implementation of the second integrated operational amplifier.
The utility model discloses an in the embodiment of current measurement circuit, adopt two operational amplifier circuits of first integrated operational amplifier and the integrated operational amplifier of second, like this, two ADC are to being surveyed signal and reference fixed voltage (standard signal) simultaneous sampling, and processing module handles two signal simultaneous processing, can further eliminate test current error and drift to measuring result's influence, improves the measuring degree of accuracy.
In an embodiment of the current measuring circuit of the present invention, the integrated operational amplifier in the analog-to-digital converter may adopt a high-precision operational amplifier circuit.
The utility model discloses an in the embodiment of current measurement circuit, analog-to-digital converter adopts high-accuracy operational amplifier circuit will sampling voltage signal's analog signal converts digital signal to, because ADC's the conversion degree of accuracy is high, can further improve the measuring accuracy to can reduce voltage loss effectively, increase current range and precision measurement, and reduce the consumption, realize intelligent acquisition, reduce cost, improve resource utilization efficiency.
The utility model discloses a current measurement circuit's embodiment can be used for detecting direct current exciting current. That is, the sampling current may be a direct current excitation current.
In an embodiment of the current measuring circuit of the present invention, the processing module may be a single chip microcomputer. The processing module can also be a signal processing system of a single chip microcomputer.
In an embodiment of the current measurement circuit of the present invention, the analog-to-digital converter and the processing module may be integrally disposed together, for example: the analog-to-digital converter is arranged in the single chip microcomputer.
The singlechip is provided with an ADC (analog to digital converter), so that continuous signals in an analog form can be converted into digital signals, and the ADC is a bridge for measuring direct-current exciting current. With the development of ADC and single chip microcomputer and the low price thereof, the single chip microcomputer signal processing system based on ADC sampling is widely applied to a resistance measuring device and a resistance measuring instrument.
As shown in fig. 1, in the embodiment of the current measuring circuit of the present invention, a current shunt may be further included, and the current shunt is configured to sample the current to be measured and output the sampled current obtained by sampling to the detection module. The current divider is used for measuring direct current, the function of the current divider is equivalent to a resistor with small resistance value, and the current divider is manufactured according to the principle that voltage is generated at two ends of the resistor when the direct current passes through the resistor.
The utility model discloses an in the embodiment of current measurement circuit, can adopt the high accuracy to have outstanding low self-heating power coefficient and low additional phase shift current shunt, can make the heat loss greatly reduce and can compensate shunt self-heating power coefficient's influence and the influence of shunt resistance value long-term stability when the system operation like this.
As shown in FIG. 1 and FIG. 2, the current divider is connected to the 1MT +/1 MT-node of the circuit.
(II) electronic device
As shown in fig. 3, the embodiment of the present invention further provides an apparatus using a current measuring circuit, the apparatus includes a detected circuit 101, the current measuring circuit 102 and a control circuit 103 in the above embodiment, the current measuring circuit 102 is used for detecting a current in the detected circuit 101, and the control circuit 103 is used for controlling the detected circuit 101 according to a measurement result of the current measuring circuit 102.
In an embodiment of the device of the present invention, the electronic device may be a power supply device.
In an embodiment of the apparatus of the present invention, the detected circuit 101 may be a motor.
In the above, although the subject matter of the present invention has been described in language specific to structural features/functional/methodological acts, the specific structural features/functional/methodological acts are merely examples of the claimed subject matter and the scope of the present invention is not limited thereto, and any changes or substitutions that may be easily made by one skilled in the art without departing from the scope of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. The circuit is characterized by comprising a detection module, an analog-to-digital converter and a processing module, wherein the detection module is used for converting an input sampling current into a sampling voltage signal, the analog-to-digital converter is used for comparing the input sampling voltage signal with a reference fixed voltage and outputting a digital signal, and the processing module is used for calculating and comparing the digital signal with a standard value and obtaining a measurement result.
2. The current measurement circuit according to claim 1, wherein the analog-to-digital converter specifically includes an integrated operational amplifier, two input terminals of the integrated operational amplifier are a first input terminal and a second input terminal, respectively, the sampling voltage signal obtained by the detection module is input through the first input terminal, the reference fixed voltage is input through the second input terminal, and the integrated operational amplifier outputs a digital signal by comparing the input sampling voltage signal with the reference fixed voltage, thereby converting the sampling voltage signal into a digital signal.
3. The current measurement circuit of claim 1, wherein the analog-to-digital converter comprises in particular a plurality of integrated operational amplifiers arranged in series.
4. The current measurement circuit of claim 1, wherein the analog-to-digital converter comprises a first integrated operational amplifier and a second integrated operational amplifier, the sampled voltage signal obtained by the detection module is input to one input terminal of the first integrated operational amplifier, a signal output from an output terminal of the first integrated operational amplifier is input to the other input terminal of the first integrated operational amplifier, a signal output from an output terminal of the first integrated operational amplifier is input to one input terminal of the second integrated operational amplifier, and the reference fixed voltage is input to the other input terminal of the second integrated operational amplifier.
5. The current measurement circuit according to claim 1, further comprising a current splitter for sampling a current to be measured and outputting a sampled current obtained by the sampling to the detection module.
6. The current measurement circuit of claim 1, wherein in one possible implementation of the current measurement circuit, the sampled current is a direct current excitation current.
7. The current measurement circuit of claim 1, wherein the processing module is a single-chip microcomputer, or the processing module is a signal processing system of a single-chip microcomputer.
8. The current measurement circuit of claim 1, wherein the analog-to-digital converter and the processing module are integrally disposed together.
9. An apparatus using a current measuring circuit, characterized in that the apparatus comprises a detected circuit, a control circuit, and the current measuring circuit as claimed in any one of claims 1 to 5, the current measuring circuit being configured to detect a current in the detected circuit, the control circuit being configured to control the detected circuit based on a measurement result of the current measuring circuit.
10. The apparatus of claim 9, wherein the circuit under test is a motor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022197696.5U CN212540524U (en) | 2020-09-29 | 2020-09-29 | Current measurement circuit and equipment applying same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022197696.5U CN212540524U (en) | 2020-09-29 | 2020-09-29 | Current measurement circuit and equipment applying same |
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| Publication Number | Publication Date |
|---|---|
| CN212540524U true CN212540524U (en) | 2021-02-12 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202022197696.5U Active CN212540524U (en) | 2020-09-29 | 2020-09-29 | Current measurement circuit and equipment applying same |
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| CN (1) | CN212540524U (en) |
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- 2020-09-29 CN CN202022197696.5U patent/CN212540524U/en active Active
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