Measurement device
By combining temperature compensation and calibration coefficient calculation in the measurement equipment, the problem of large current measurement error of low-power products is solved, and higher measurement accuracy and stability are achieved.
Patent Information
- Application Number
- CN202323506803.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-21
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2033-12-21
AI Technical Summary
The current measurement error of low-power consumption products in the prior art is large, which affects the accuracy of power consumption evaluation and causes inconvenience for R&D and production testers.
A measurement device is designed, including an interface unit, a conversion unit, an amplification unit, an analog-to-digital conversion unit, a main control unit and a temperature compensation unit, which improves the current measurement through temperature compensation, calibration coefficient calculation and multiple sampling average value. Accuracy.
It effectively reduces the impact of temperature on current measurement, and improves the accuracy and stability of current measurement through calibration coefficient correction and multiple sampling calculations.
Smart Images
Figure CN222189382U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of electronic product detection, and in particular to a measuring device. Background Art
[0002] With the advancement of science and technology, the improvement of living standards, people's demand for smart electronic products is becoming increasingly strong. At present, many smart electronic products on the market, such as Bluetooth headsets, Bluetooth bracelets, digital car keys, etc., have brought a lot of convenience to people's lives. However, most of these smart electronic products are powered by batteries, and the available power is limited. Therefore, the power consumption evaluation of such low-power products is particularly important. The power consumption test is mainly the measurement of current. The accuracy of current measurement directly determines the accuracy of power consumption evaluation. However, at present, due to certain limitations in the design and implementation of current measurement circuits, the current measurement error of low-power products is large, which brings many inconveniences to R&D personnel, production testers, etc. Utility Model Content
[0003] In view of this, it is necessary to provide a measuring device to reduce the measurement error and improve the accuracy of current measurement.
[0004] The embodiment of the present application discloses a measuring device for measuring the current of a circuit to be measured, comprising: an interface unit for accessing the circuit to be measured; a conversion unit electrically connected to the interface unit, for obtaining the current to be measured of the circuit to be measured and converting the current to be measured into a voltage; an amplification unit electrically connected to the conversion unit, for amplifying the voltage and outputting the amplified voltage; an analog-to-digital conversion unit electrically connected to the amplification unit, for receiving the amplified voltage and converting the amplified voltage into a digital signal; a main control unit electrically connected to the analog-to-digital conversion unit and the interface unit, for receiving the digital signal and calculating the current value of the current to be measured based on the digital signal; and a temperature compensation unit electrically connected to the main control unit, for detecting the ambient temperature and transmitting the ambient temperature to the main control unit so that the main control unit adjusts the current value based on the ambient temperature.
[0005] Preferably, the main control unit has a built-in correspondence table of temperature and current compensation values; the main control unit is further used to adjust the current value according to the correspondence table of temperature and current compensation values and the ambient temperature.
[0006] Preferably, the main control unit is also used to: when the interface unit is connected to the circuit to be tested, determine whether the circuit to be tested needs to be measured; when it is determined that the circuit to be tested needs to be measured, output a first test control signal; when it is determined that the circuit to be tested does not need to be measured, output a second test control signal.
[0007] Preferably, it also includes: a first switching unit, electrically connected between the interface unit and the conversion unit, and also electrically connected to the main control unit, used to connect the connection between the interface unit and the conversion unit according to the first test control signal, and also used to disconnect the connection between the interface unit and the conversion unit according to the second test control signal.
[0008] Preferably, it also includes a constant current source calibration unit, which is electrically connected to the conversion unit and is used to output a calibration current of a preset current value to the conversion unit; the conversion unit is also used to convert the calibration current into a calibration voltage and transmit it to the amplification unit; the amplification unit is also used to receive the calibration voltage and output the amplified calibration voltage; the analog-to-digital conversion unit is also used to receive the amplified calibration voltage and convert the amplified calibration voltage into a calibration digital signal; the main control unit is also used to calculate the measured current value of the calibration current according to the calibration digital signal, and calculate the calibration coefficient according to the measured current value and the preset current value.
[0009] Preferably, the main control unit is further used to correct the current value of the current to be measured according to the calibration coefficient.
[0010] Preferably, the main control unit is further used to sample and calculate the current value of the current to be measured multiple times within a preset time, and calculate the current average value.
[0011] Preferably, the main control unit is further used to set a calibration period and output a calibration signal according to the calibration period.
[0012] Preferably, it also includes: a second switch unit, electrically connected between the constant current source calibration unit and the conversion unit, and also electrically connected to the main control unit, for conducting the connection between the constant current source calibration unit and the conversion unit according to the calibration signal.
[0013] Preferably, it also includes: a reference voltage source, electrically connected to the analog-to-digital conversion unit, for providing a constant voltage to the analog-to-digital conversion unit; and a display unit, electrically connected to the main control unit, for displaying the current value of the circuit to be tested.
[0014] Compared with the prior art, in the measuring device provided by the embodiment of the present application, the temperature compensation unit detects the ambient temperature and transmits the ambient temperature to the main control unit so that the main control unit adjusts the current value according to the ambient temperature, thereby reducing the influence of temperature on the current measurement and improving the measurement accuracy; by calculating the calibration coefficient and correcting the current value according to the calibration coefficient; by calculating the current value of the current to be measured by multiple sampling within a preset time, and taking the current average value as the final current measurement value, the measurement accuracy is further improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a functional module diagram of one implementation of the measuring device of the present application.
[0016] Figure 2 It is a functional module diagram of another embodiment of the measuring device of the present application.
[0017] Main component symbols
[0018] 10-Measuring equipment
[0019] 20-Circuit under test
[0020] 101-Interface Unit
[0021] 102-Conversion Unit
[0022] 103-Amplification unit
[0023] 104-Analog-to-digital conversion unit
[0024] 105-Main control unit
[0025] 106-Temperature compensation unit
[0026] 107-First switch unit
[0027] 108-Constant current source calibration unit
[0028] 109-Second switch unit
[0029] 110-Reference voltage source
[0030] 111-Display unit DETAILED DESCRIPTION
[0031] The technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application.
[0032] It is understandable that the connection relationship described in this application refers to direct or indirect connection. For example, the connection between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components. For example, A and C can be directly connected, and C and B can be directly connected, so that A and B are connected through C. It is also understandable that the "A connects B" described in this application can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.
[0033] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is only a way to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.
[0034] In the description of this application, words such as "first" and "second" are only used to distinguish different objects, and do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.
[0035] The technical solution of the present application is further described in detail below in conjunction with the accompanying drawings.
[0036] See also Figure 1 , Figure 1 1 is a functional module diagram of an embodiment of the measuring device of the present application. The measuring device 10 can be used to measure the current of the circuit to be tested 20. The circuit to be tested 20 can be a circuit in an electronic device, and the electronic device is preferably a low-power electronic product, such as a Bluetooth headset, a Bluetooth bracelet, a digital car key, etc. The embodiment of the present application does not limit the type of electronic device.
[0037] In this embodiment, the measuring device 10 includes an interface unit 101, a conversion unit 102, an amplifying unit 103, an analog-to-digital conversion unit 104, a main control unit 105 and a temperature compensation unit 106. The interface unit 101 is used to access the circuit to be tested 20. The interface unit 101 can be a USB interface, a UART interface or other interfaces. Specifically, a suitable type of interface can be selected according to the actual application, which is not limited here. The conversion unit 102 is electrically connected to the interface unit 101, and is used to obtain the current to be tested of the circuit to be tested 20, and convert the current to be tested into a voltage. The amplifying unit 103 is electrically connected to the conversion unit 102, and is used to amplify the voltage and output the amplified voltage. The analog-to-digital conversion unit 104 is electrically connected to the amplifying unit 103, and is used to receive the amplified voltage and convert the amplified voltage into a digital signal. The analog-to-digital conversion unit 104 may include a zero-drift high-precision and high-sampling rate analog-to-digital conversion chip, such as AD8428, to improve the accuracy and stability of the measurement. The main control unit 105 is electrically connected to the analog-to-digital conversion unit 104 and the interface unit 101, and is used to receive the digital signal and calculate the current value of the current to be measured according to the digital signal. The main control unit 105 may include a microcontroller (Microcontroller Unit, MCU) with control and signal processing capabilities. The main control unit 105 can be an STM32 chip based on the ARMCortex core. The temperature compensation unit 106 is electrically connected to the main control unit 105, and is used to detect the ambient temperature, and transmit the ambient temperature to the main control unit, so that the main control unit adjusts the current value according to the ambient temperature.
[0038] In practical applications, the current measurement process is easily affected by the ambient temperature, resulting in low accuracy of current measurement. In this embodiment, the main control unit 105 has a built-in correspondence table of temperature and current compensation value; the main control unit 105 adjusts the current value according to the correspondence table of temperature and current compensation value, thereby reducing the influence of ambient temperature on current measurement and improving measurement accuracy. In order to reduce measurement errors, the main control unit 105 also samples and calculates the current value of the current to be measured multiple times within a preset time, and takes the current average value as the final current measurement value.
[0039] See also Figure 2 , Figure 2 This is a functional module diagram of another embodiment of the measuring device of the present application. The measuring device 10 can be used to measure the current of the circuit to be tested 20. The circuit to be tested 20 can be a circuit in an electronic device, and the electronic device is preferably a low-power electronic product, such as a Bluetooth headset, a Bluetooth bracelet, a digital car key, etc. The embodiment of the present application does not limit the type of electronic device.
[0040] The difference between this embodiment and the above embodiment is that the measuring device 10 further includes a first electronic switch 107. The first electronic switch 107 is electrically connected between the interface unit 101 and the conversion unit 102, and is also electrically connected to the main control unit 105, and is used to turn on or off the connection between the interface unit 101 and the conversion unit 105. Specifically, when the interface unit 101 is connected to the circuit to be tested 20, the main control unit 105 is also used to determine whether the circuit to be tested 20 needs to be measured. When it is determined that the circuit to be tested 20 needs to be measured, the main control unit 105 outputs a first test control signal to the first switch unit 107; when it is determined that the circuit to be tested 20 does not need to be measured, the main control unit 105 outputs a second test control signal to the first switch unit 107. The first switch unit 107 turns on the connection between the interface unit 101 and the conversion unit 102 according to the first test control signal, and also disconnects the connection between the interface unit 101 and the conversion unit 102 according to the second test control signal.
[0041] In this embodiment, the measuring device 10 also includes a constant current source calibration unit 108, which is electrically connected to the conversion unit 102 and is used to output a calibration current of a preset current value to the conversion unit 102. Similar to the process of measuring the current value of the circuit to be measured 20, the conversion unit 102 converts the calibration current into a calibration voltage and transmits it to the amplification unit 103. The amplification unit 103 receives the calibration voltage and outputs the amplified calibration voltage. The analog-to-digital conversion unit 104 receives the amplified calibration voltage and converts the amplified calibration voltage into a calibration digital signal. The main control unit 105 calculates the measured current value of the calibration current according to the calibration digital signal, and calculates the calibration coefficient according to the measured current value and the preset current value. Then, the calibration coefficient of the main control unit 105 corrects the current value of the current to be measured. The main control unit 105 can also set a calibration cycle, which can be set to one week, that is, calibration once a week, or calibration is performed before each measurement. The calibration cycle can be determined according to the test requirements and is not limited here. The main control unit 105 outputs a calibration signal according to the set calibration cycle. Through the calibration process, the calibration coefficient is determined according to the difference between the actual measured value and the standard value, so as to correct the current measurement error and further improve the current measurement accuracy.
[0042] In this embodiment, in order to reduce the measurement error, the main control unit 105 further samples and calculates the current value of the current to be measured for multiple times within a preset time, and takes the current average value as the final current measurement value.
[0043] In this embodiment, the measuring device 10 further includes a second switch unit 109. The second switch unit 109 is electrically connected between the constant current source calibration unit 108 and the conversion unit 102, and is also electrically connected to the main control unit 105, and is used to conduct the connection between the constant current source calibration unit 108 and the conversion unit 102 according to the calibration signal.
[0044] The measuring device 10 further includes a reference voltage source 110. The reference voltage source 110 is electrically connected to the analog-to-digital conversion unit 104, and is used to provide a constant voltage to the analog-to-digital conversion unit 104. In this embodiment, the analog-to-digital conversion unit 104 is powered separately by the reference voltage source 110, and the reference voltage source 110 can output a ripple-stable voltage, thereby ensuring the power supply stability and reliability of the analog-to-digital conversion unit 104, and reducing the impact of power supply fluctuations on current measurement. The measuring device 10 may further include a display device 111. The display device 111 is electrically connected to the main control unit 105, and is used to display the current value of the circuit to be measured, and can also be used to display calibration coefficients, etc.
[0045] Compared with the prior art, in the measuring device provided by the embodiment of the present application, the temperature compensation unit detects the ambient temperature and transmits the ambient temperature to the main control unit so that the main control unit adjusts the current value according to the ambient temperature, thereby reducing the influence of temperature on the current measurement and improving the measurement accuracy; by calculating the calibration coefficient and correcting the current value according to the calibration coefficient; by calculating the current value of the current to be measured by multiple sampling within a preset time, and taking the current average value as the final current measurement value, the measurement accuracy is further improved.
[0046] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.
Claims
1. A measuring device for measuring the current of a circuit to be measured, characterized in that: include: An interface unit, used for accessing the circuit to be tested; A conversion unit, electrically connected to the interface unit, for acquiring a current to be measured of the circuit to be measured and converting the current to be measured into a voltage; an amplifying unit, electrically connected to the converting unit, for amplifying the voltage and outputting the amplified voltage; an analog-to-digital conversion unit, electrically connected to the amplification unit, for receiving the amplified voltage and converting the amplified voltage into a digital signal; A main control unit, electrically connected to the analog-to-digital conversion unit and the interface unit, for receiving the digital signal and calculating the current value of the current to be measured according to the digital signal; The temperature compensation unit is electrically connected to the main control unit, and is used for detecting the ambient temperature and transmitting the ambient temperature to the main control unit, so that the main control unit adjusts the current value according to the ambient temperature.
2. The measuring device according to claim 1, characterized in that: The main control unit has a built-in correspondence table of temperature and current compensation values; The main control unit is further used to adjust the current value according to the correspondence table between the temperature and the current compensation value and the ambient temperature.
3. The measuring device according to claim 1, characterized in that: The main control unit is also used for: When the interface unit is connected to the circuit to be tested, determining whether the circuit to be tested needs to be measured; When it is determined that the circuit to be tested needs to be measured, outputting a first test control signal; When it is determined that the circuit to be tested does not need to be measured, a second test control signal is output.
4. The measuring device according to claim 3, characterized in that: Also includes: A first switch unit is electrically connected between the interface unit and the conversion unit, and is also electrically connected to the main control unit, and is used to connect the interface unit and the conversion unit according to the first test control signal, and is also used to disconnect the interface unit and the conversion unit according to the second test control signal.
5. The measuring device according to claim 2, characterized in that: It also includes a constant current source calibration unit, which is electrically connected to the conversion unit and is used to output a calibration current of a preset current value to the conversion unit; The conversion unit is further used to convert the calibration current into a calibration voltage and transmit it to the amplification unit; The amplifying unit is further used to receive the calibration voltage and output the amplified calibration voltage; The analog-to-digital conversion unit is further used to receive the amplified calibration voltage and convert the amplified calibration voltage into a calibration digital signal; The main control unit is further used to calculate a measured current value of the calibration current according to the calibration digital signal, and calculate a calibration coefficient according to the measured current value and the preset current value.
6. The measuring device according to claim 5, characterized in that: The main control unit is further used to correct the current value of the current to be measured according to the calibration coefficient.
7. The measuring device according to claim 6, characterized in that The main control unit is also used for: The current value of the current to be measured is calculated by sampling multiple times within a preset time, and the current average value is calculated.
8. The measuring device according to claim 6, characterized in that: The main control unit is further used to set a calibration period and output a calibration signal according to the calibration period.
9. The measuring device according to claim 8, characterized in that: Also includes: The second switch unit is electrically connected between the constant current source calibration unit and the conversion unit, and is also electrically connected to the main control unit, and is used to conduct the connection between the constant current source calibration unit and the conversion unit according to the calibration signal.
10. The measuring device according to claim 1, characterized in that: Also includes: A reference voltage source, electrically connected to the analog-to-digital conversion unit, for providing a constant voltage to the analog-to-digital conversion unit; The display unit is electrically connected to the main control unit and is used to display the current value of the circuit to be tested.