CN217060325U - Instrument with automatic range switching function - Google Patents
Instrument with automatic range switching function Download PDFInfo
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- CN217060325U CN217060325U CN202220205618.1U CN202220205618U CN217060325U CN 217060325 U CN217060325 U CN 217060325U CN 202220205618 U CN202220205618 U CN 202220205618U CN 217060325 U CN217060325 U CN 217060325U
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Abstract
The utility model provides a range automatic switch-over's instrument, including range automatic switch-over circuit, range automatic switch-over circuit includes sampling module, signal amplification module, VREF module and MCU module, and sampling module's output is connected with signal amplification module's input and MCU module's input respectively, and the output of VREF module is connected with signal amplification module's input, and signal amplification module's output links to each other with the input of MCU module. The utility model provides an instrument for automatically switching measuring ranges, which collects and measures original signals and amplified signals simultaneously, and selects signals to be measured according to the original signals, thereby realizing the automatic switching of measuring signals during full-range measurement and ensuring the measuring precision of the whole range; the circuit is simple, the cost is low, and the design and the production are easy; the switching of the measuring range during the measurement has no influence on the load equipment, is suitable for continuous accurate measurement, and further improves the measurement precision.
Description
Technical Field
The utility model relates to a measuring instrument technical field especially relates to an instrument of range automatic switch-over.
Background
In the current measuring instrument, the current signal to be measured is often wide, so that in order to improve the measurement accuracy in the whole range, the measurement needs to be performed in a segmented manner, or a higher-resolution AD converter is used.
When a high-resolution AD converter is used, the cost is high. When the electronic switch is used for range switching, the cost is high, the circuit design is complex, the semiconductor electronic switch is not completely closed when being closed, and a small current measurement result with microampere or even lower magnitude is influenced by weak leakage current.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a measuring range automatic switch-over's instrument can solve one or more among the above-mentioned prior art problem.
According to an aspect of the utility model, an aspect provides a range automatic switch-over's instrument, including range automatic switch-over circuit, range automatic switch-over circuit includes sampling module, the signal amplification module, VREF module and MCU module, sampling module's output is connected with the input of signal amplification module and the input of MCU module respectively, the output of VREF module is connected with the input of signal amplification module, the output of signal amplification module links to each other with the input of MCU module, sampling module is used for gathering original signal, the signal amplification module is used for enlarging original signal, the MCU module is used for acquireing original signal and measures with the signal after enlarging, and select to carry out the signal of measuring according to the measured value of original signal.
In some embodiments, the sampling module includes a current transformer CT1 and a sampling resistor R1, the current transformer CT1 is connected to two ends of the sampling resistor R1, two ends of the sampling resistor R1 are respectively connected to the signal amplification module, and one end of the sampling resistor R1 is connected to the MCU module.
In some embodiments, the signal amplification module includes an operational amplifier D1, a non-inverting input terminal of the operational amplifier D1 is connected to one end of the sampling resistor R1 through a resistor R2, an inverting input terminal of the operational amplifier D1 is connected to the other end of the sampling resistor R1 through a resistor R3, and an output terminal of the operational amplifier D1 is connected to the MCU module.
In some embodiments, a resistor R4 is connected between the inverting input of the operational amplifier D1 and the output of the operational amplifier D1.
In some embodiments, the output of the VREF block is connected to the inverting input of operational amplifier D1 through resistor R3.
In some embodiments, the VREF module includes a resistor R5, a resistor R6, and an operational amplifier D2, one end of the resistor R5 is connected to the power supply, the other end of the resistor R6 is connected to the inverting input terminal of the operational amplifier D2, the other end of the resistor R6 is connected to the ground, the other end of the resistor R6 is connected to the inverting input terminal of the operational amplifier D2, and the output terminal of the operational amplifier D2 is connected to the signal amplification module.
The utility model provides an instrument of range automatic switch-over, through carrying out once amplification to the original signal of measuring, gather and measure original signal and signal after the amplification simultaneously to select to carry out the signal of measuring according to original signal, the automatic switch-over of measuring signal when realizing full-range measurement has guaranteed the measurement accuracy of whole range; the circuit is simple, the cost is low, and the design and the production are easy; the switching of the measuring range during the measurement has no influence on the load equipment, is suitable for continuous accurate measurement, and further improves the measurement precision.
In addition, in the technical solutions of the present invention, the technical solutions can be implemented by adopting conventional means in the art, which are not specifically described.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an automatic range switching circuit in an instrument according to an embodiment of the present invention.
Fig. 2 is a circuit diagram of the sampling module, the signal amplification module and the MCU module of the automatic range switching circuit of the automatic range switching instrument according to an embodiment of the present invention.
Fig. 3 is a circuit diagram of a VREF module of an automatic range switching circuit in an instrument according to an embodiment of the present invention.
Detailed Description
To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the attached drawings in the embodiments of the present invention are combined to clearly and completely describe the technical solution in the embodiments of the present invention, and obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
The embodiment is as follows:
in this embodiment, and with reference to the accompanying figures 1-3 of the specification, there is provided a gauge with automatic range switching, the automatic range switching instrument comprises an automatic range switching circuit, the automatic range switching circuit comprises a sampling module 1, a signal amplification module 2, a VREF module 3 and an MCU module 4, the output end of the sampling module 1 is respectively connected with the input end of the signal amplification module 2 and the input end of the MCU module 4, the output end of the VREF module 3 is connected with the input end of the signal amplification module 2, the output end of the signal amplification module 2 is connected with the input end of the MCU module 4, the sampling module 1 is used for collecting original signals, the signal amplification module 2 is used for amplifying the original signals, and the MCU module 4 is used for acquiring the original signals and the amplified signals to measure and selecting the signals to measure according to the measured values of the original signals.
In an optional embodiment, the sampling module 1 includes a current transformer CT1 and a sampling resistor R1, the current transformer CT1 is connected to two ends of the sampling resistor R1, two ends of the sampling resistor R1 are respectively connected to the signal amplification module 2, and one end of the sampling resistor R1 is connected to the MCU module 4. Thus, the current signal to be measured is converted into a raw signal, I1, through the current transformer CT1 and the sampling resistor R1.
In an alternative embodiment, the signal amplifying module 2 includes an operational amplifier D1, a non-inverting input terminal of the operational amplifier D1 is connected to one end of the sampling resistor R1 through a resistor R2, an inverting input terminal of the operational amplifier D1 is connected to the other end of the sampling resistor R1 through a resistor R3, and an output terminal of the operational amplifier D1 is connected to the MCU module. Thus, the original signal I1 is amplified by the signal amplification module to obtain an amplified signal, which is denoted as I1X.
In an alternative embodiment, a resistor R4 is connected between the inverting input of the operational amplifier D1 and the output of the operational amplifier D1.
In an alternative embodiment, the output of VREF block 3 is connected to the inverting input of op-amp D1 through resistor R3.
In an alternative embodiment, the VREF module 3 includes a resistor R5, a resistor R6, and an operational amplifier D2, one end of the resistor R5 is connected to the power supply, the other end is connected to the inverting input terminal of the operational amplifier D2, one end of the resistor R6 is grounded, the other end is connected to the inverting input terminal of the operational amplifier D2, and the output terminal of the operational amplifier D2 is connected to the signal amplification module 2.
In an optional embodiment, the MCU module 4 includes a chip U1 with a model number HC32F005, a signal input end of the chip U1 is connected to an output end of the sampling module 1 and an output end of the signal amplifying module 2, respectively, and the chip U1 acquires an original signal I1 and an amplified signal I1X, and performs measurement. Whether the measurement is performed using I1 or I1X is determined according to whether the measurement value of the original signal I1 satisfies a preset range of measurement range. For example, assuming that the measurable current range of the meter with automatic switching of the measuring range is 0-5A, the preset 0-50mA is measured by using the amplified signal I1X, when the measured value of the original signal I1 is less than 50mA, the amplified signal I1X is used for measurement, and when the measured value of the original signal I1 is more than 50mA, the original signal I1X is used for measurement. Therefore, when the current value to be measured is small, the amplified signal is automatically switched to be used for measurement, so that the measurement accuracy is ensured, the measurement result is more accurate, and the measurement accuracy of the whole range is improved.
In an alternative embodiment, the MCU module 4 may also transmit the measurement result to the display module for output and display.
In an alternative embodiment, the sampling resistor R1 may be a high precision resistor, further improving the accuracy of the current measurement.
The utility model provides an instrument of range automatic switch-over, through carrying out once amplification to the original signal of measuring, gather and measure original signal and signal after the amplification simultaneously to select to carry out the signal of measuring according to original signal, the automatic switch-over of measuring signal when realizing full-range measurement has guaranteed the measurement accuracy under the whole range; the circuit is simple, the cost is low, and the design and the production are easy; the switching of the measuring range during the measurement has no influence on the load equipment, is suitable for continuous accurate measurement, and further improves the measurement precision.
The foregoing is only an alternative embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (6)
1. The instrument capable of automatically switching the measuring ranges is characterized by comprising an automatic measuring range switching circuit, wherein the automatic measuring range switching circuit comprises a sampling module, a signal amplification module, a VREF module and an MCU module, the output end of the sampling module is respectively connected with the input end of the signal amplification module and the input end of the MCU module, the output end of the VREF module is connected with the input end of the signal amplification module, the output end of the signal amplification module is connected with the input end of the MCU module, the sampling module is used for collecting original signals, the signal amplification module is used for amplifying the original signals, and the MCU module is used for acquiring the original signals and the amplified signals to measure and selecting the signals to measure according to the measured values of the original signals.
2. The instrument for automatically switching the measuring range according to claim 1, wherein the sampling module comprises a current transformer CT1 and a sampling resistor R1, the current transformer CT1 is connected to two ends of the sampling resistor R1, two ends of the sampling resistor R1 are respectively connected to the signal amplification module, and one end of the sampling resistor R1 is connected to the MCU module.
3. The instrument for automatically switching the measuring range according to claim 2, wherein the signal amplifying module comprises an operational amplifier D1, the non-inverting input terminal of the operational amplifier D1 is connected with one end of a sampling resistor R1 through a resistor R2, the inverting input terminal of the operational amplifier D1 is connected with the other end of the sampling resistor R1 through a resistor R3, and the output terminal of the operational amplifier D1 is connected with the MCU module.
4. The automatic range switching instrument according to claim 3, wherein a resistor R4 is connected between the inverting input terminal of the operational amplifier D1 and the output terminal of the operational amplifier D1.
5. The automatic range switching instrument according to claim 3, wherein the output end of the VREF module is connected with the inverting input end of the operational amplifier D1 through a resistor R3.
6. The instrument for automatically switching the measuring range according to claim 1, wherein the VREF module comprises a resistor R5, a resistor R6 and an operational amplifier D2, one end of the resistor R5 is connected to a power supply, the other end of the resistor R5 is connected to the inverting input terminal of the operational amplifier D2, one end of the resistor R6 is grounded, the other end of the resistor R6 is connected to the inverting input terminal of the operational amplifier D2, and the output terminal of the operational amplifier D2 is connected to the signal amplification module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220205618.1U CN217060325U (en) | 2022-01-25 | 2022-01-25 | Instrument with automatic range switching function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220205618.1U CN217060325U (en) | 2022-01-25 | 2022-01-25 | Instrument with automatic range switching function |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217060325U true CN217060325U (en) | 2022-07-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220205618.1U Active CN217060325U (en) | 2022-01-25 | 2022-01-25 | Instrument with automatic range switching function |
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| CN (1) | CN217060325U (en) |
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- 2022-01-25 CN CN202220205618.1U patent/CN217060325U/en active Active
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