CN113671242A - Voltage measurement device and method - Google Patents

Abstract

The present application relates to a voltage measurement device and method. The device comprises: the maximum measuring range measuring unit comprises a fixed gain amplifier and a first analog-to-digital converter; the fixed gain amplifier scales a signal to be measured by a fixed multiple, and the first analog-to-digital converter measures the signal to be measured to obtain a first voltage value; the adjustable range measuring unit comprises an adjustable gain amplifier and a second analog-to-digital converter which are connected; the adjustable gain amplifier scales the signal to be measured by adjustable times, and the second analog-to-digital converter measures the signal to be measured to obtain a second voltage value; the processor is used for determining a target measuring range when the first voltage value is within the maximum measuring range of the adjustable measuring range measuring unit; adjusting the adjustable multiple to correspond to the target measurement range; and outputting a first voltage value within a set time length after the target measuring range is determined. The device can automatically switch the measuring range according to the signal to be measured, and continuous measurement of voltage is realized.

Description

Voltage measurement device and method

Technical Field

The present disclosure relates to circuit measurement technologies, and in particular, to a voltage measurement apparatus and method.

Background

With the development of electronic circuit technology, the requirements for the continuity and accuracy of the measured voltage are higher and higher. For different voltage signals, different measuring ranges are required to be used for measurement, so that the measurement accuracy is improved.

In the conventional technology, the range of the voltage measuring device is adjusted manually by controlling the action of a selection switch according to a voltage signal to be measured.

However, in the conventional art, the range of the voltage measuring device cannot be automatically switched according to the real-time signal to be measured, so that the measurement result is not accurate enough. In addition, since the selection switch needs a certain time to operate, the conventional scheme may cause the voltage measurement channel to be disconnected during the operation of the selection switch, thereby causing interruption and missing of the voltage measurement, and causing inaccurate measurement.

Disclosure of Invention

In view of the above, it is desirable to provide a voltage measuring device and method capable of automatically switching the range according to the signal to be measured and still maintaining accurate voltage measurement during the switching of the range.

A voltage measurement apparatus, the apparatus comprising: the maximum measuring range measuring unit comprises a fixed gain amplifier and a first analog-to-digital converter which are connected; the fixed gain amplifier is used for scaling a signal to be measured by a fixed multiple, and the first analog-to-digital converter is used for measuring the voltage of the signal to be measured after the fixed gain amplifier is scaled and outputting a first measured voltage value; the adjustable range measuring unit comprises an adjustable gain amplifier and a second analog-to-digital converter which are connected; the adjustable gain amplifier is used for scaling the signal to be measured by an adjustable multiple, and the second analog-to-digital converter is used for measuring the voltage of the signal to be measured after the adjustable gain amplifier is scaled and outputting a second measured voltage value; the adjustable multiple corresponds to one of a plurality of measuring ranges of the adjustable range measuring unit, and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit; the processor is respectively connected with the first analog-to-digital converter, the adjustable gain amplifier and the second analog-to-digital converter and used for determining the target measuring range of the adjustable range measuring unit when the first voltage value is within the maximum measuring range of the adjustable range measuring unit; controlling the adjustable gain amplifier to adjust the adjustable multiple to correspond to the target measuring range; and outputting the first voltage value within the set time length after the target measuring range is determined.

In one embodiment, the processor is configured to determine a target measurement range of the adjustable range measurement unit according to the first voltage value when the second voltage value is outside the current measurement range of the adjustable range measurement unit; and when the second voltage value is within the current measuring range of the adjustable range measuring unit, determining the target measuring range of the adjustable range measuring unit according to the second voltage value.

In one embodiment, the processor is configured to determine a first proportion of the first voltage value in each measurement range of the adjustable range measurement unit; screening out the first proportion which is smaller than the upper proportion limit and larger than the lower proportion limit; determining the measuring range corresponding to the maximum proportion in the screened first proportion as the target measuring range of the adjustable measuring range measuring unit; or, determining a second proportion of the second voltage value in each measuring range of the adjustable range measuring unit; screening out the second proportion which is smaller than the upper proportion limit and larger than the lower proportion limit; determining the measuring range corresponding to the maximum proportion in the screened second proportion as the target measuring range of the adjustable measuring range measuring unit; the upper limit of the proportion is a judgment reference for determining whether the second voltage value exceeds the upper limit of the measuring range of the adjustable range measuring unit; the lower proportional limit is a criterion for determining whether the second voltage value is lower than the lower measuring range limit of the adjustable measuring range measuring unit.

In one embodiment, the processor is configured to determine a proportion of the second voltage value in a current measurement range of the second analog-to-digital converter; when the proportion of the second voltage value in the current measuring range of the second analog-to-digital converter is between the upper proportion limit and the lower proportion limit, determining that the second voltage value is in the current measuring range of the adjustable range measuring unit; and when the proportion of the second voltage value in the current measuring range of the second analog-to-digital converter is larger than the upper proportion limit or smaller than the lower proportion limit, determining that the second voltage value is out of the current measuring range of the adjustable range measuring unit.

In one embodiment, the processor is configured to, when the second voltage value gradually increases, take a first upper ratio limit as the upper ratio limit and a first lower ratio limit as the lower ratio limit; and when the second voltage value is gradually reduced, taking a second proportion upper limit as the proportion upper limit, taking a second proportion lower limit as the proportion lower limit, wherein the second proportion upper limit is smaller than the first proportion upper limit, and the second proportion lower limit is smaller than the first proportion lower limit.

In one embodiment, the processor is configured to output the first voltage value measured at a first time when the first voltage value measured at the first time is outside the maximum measurement range of the adjustable range measurement unit; determining whether the first voltage value measured at the second moment is within the maximum measuring range of the adjustable range measuring unit; wherein the second time is after the first time.

In one embodiment, the set time length is longer than the longest time required for the adjustable gain amplifier to adjust the adjustable multiple to correspond to the target measurement range.

In one embodiment, the processor is configured to, outside the set duration after the target measurement range is determined, output the second voltage value measured at the first time when the second voltage value measured at the first time is within the target measurement range and the target measurement range is a minimum measurement range of all measurement ranges of the second voltage value measured at the first time; determining whether the second voltage value measured at the second moment is within the target measuring range or not, and whether the target measuring range is the minimum measuring range of all measuring ranges of the second voltage value measured at the second moment or not; wherein the second time is after the first time.

In one embodiment, the processor is configured to determine whether the first voltage value is within the maximum measurement range of the adjustable-range measurement unit outside the set duration after the target measurement range is determined, when the second voltage value is outside the target measurement range, or when the target measurement range is not the minimum measurement range of all measurement ranges of the second voltage value.

A method of voltage measurement, the method comprising:

zooming a signal to be measured by a fixed gain amplifier by a fixed multiple, and measuring the zoomed signal to be measured of the fixed gain amplifier by a first analog-to-digital converter to obtain a first voltage value; the fixed gain amplifier and the first analog-to-digital converter are connected to form a maximum measuring range measuring unit;

the signal to be measured is zoomed by an adjustable gain amplifier by an adjustable multiple, and the zoomed signal to be measured of the adjustable gain amplifier is measured by a second analog-to-digital converter to obtain a second voltage value; the adjustable gain amplifier and the second analog-to-digital converter are connected to form an adjustable range measuring unit, the adjustable multiple corresponds to one of a plurality of measuring ranges of the adjustable range measuring unit, and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit;

when the first voltage value is within the maximum measuring range of the adjustable range measuring unit, determining the target measuring range of the adjustable range measuring unit; controlling the adjustable gain amplifier to adjust the adjustable multiple to correspond to the target measuring range; and outputting the first voltage value within a set time length after the target measuring range of the adjustable range measuring unit is determined.

According to the voltage measuring device and the voltage measuring method, the fixed gain amplifier and the first analog-to-digital converter are connected to form the maximum measuring range measuring unit, the fixed gain amplifier scales the signal to be measured by a fixed multiple, and the first analog-to-digital converter measures the voltage of the signal to be measured after the fixed gain amplifier scales and outputs the measured first voltage value. Meanwhile, the adjustable gain amplifier and the second analog-to-digital converter are connected to form an adjustable range measuring unit, the adjustable gain amplifier scales the signal to be measured by an adjustable multiple, and the second analog-to-digital converter measures the voltage of the signal to be measured after the adjustable gain amplifier scales and outputs a second measured voltage value. Because the adjustable multiple corresponds to one of the multiple measuring ranges of the adjustable range measuring unit and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit, the adjustable range measuring unit can realize the accurate measurement of the voltage in a small range, and the maximum range measuring unit can realize the rough measurement of the voltage in the maximum range. When the first voltage value is within the maximum measuring range of the adjustable range measuring unit, the target measuring range of the adjustable range measuring unit can be determined, and the adjustable gain amplifier is controlled to adjust the adjustable multiple to be corresponding to the target measuring range, so that the measuring range of the adjustable range measuring unit can be automatically switched. When the adjustable gain amplifier adjusts the adjustable multiple or the scaled signal to be measured is outside the measurement range of the second analog-to-digital converter, the second voltage value measured by the adjustable range measurement unit is inaccurate, and the processor outputs the first voltage value at the moment, so that the continuity of voltage measurement can be maintained and the measurement result is accurate under the condition that the measurement of the adjustable range measurement unit is inaccurate.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a voltage measurement device according to an embodiment;

FIG. 2 is a flow chart of the operation of the voltage measurement device in one embodiment;

FIG. 3 is a flow diagram of voltage output during span switching in one embodiment;

FIG. 4 is a schematic diagram of a gradual voltage change in one embodiment;

FIG. 5 is a flowchart illustrating a voltage measurement method according to an embodiment.

Description of reference numerals:

10-fixed gain amplifier, 11-adjustable gain amplifier, 20-first analog-to-digital converter, 21-second analog-to-digital converter and 30-processor.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. Further, "connection" in the following embodiments is understood to mean "electrical connection", "communication connection", or the like, if there is a transfer of electrical signals or data between the connected objects.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

In one embodiment, as shown in fig. 1, a voltage measurement device is provided that includes a fixed gain amplifier 10, an adjustable gain amplifier 11, a first analog-to-digital converter 20, a second analog-to-digital converter 21, and a processor 30. The maximum range measuring unit comprises a fixed gain amplifier 10 and a first analog-to-digital converter 20 which are connected. The fixed gain amplifier 10 is configured to scale the signal to be measured by a fixed multiple, and the first analog-to-digital converter 20 is configured to measure a voltage of the signal to be measured after the fixed gain amplifier 10 scales the signal to be measured and output a first measured voltage value. The adjustable range measuring unit comprises an adjustable gain amplifier 11 and a second analog-to-digital converter 21 which are connected. The adjustable gain amplifier 11 is configured to scale the signal to be measured by an adjustable multiple, and the second analog-to-digital converter 21 is configured to measure a voltage of the signal to be measured after the adjustable gain amplifier 11 is scaled, and output a second measured voltage value. The adjustable multiple corresponds to one of the measuring ranges of the adjustable range measuring unit, and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit. And the processor 30 is connected with the first analog-to-digital converter 20, the adjustable gain amplifier 11 and the second analog-to-digital converter 21 respectively.

As shown in fig. 2, the processor 30 is configured to perform the following steps:

and S100, when the first voltage value is within the maximum measuring range of the adjustable range measuring unit, determining the target measuring range of the adjustable range measuring unit.

And S110, controlling the adjustable gain amplifier to adjust the adjustable multiple to correspond to the target measuring range of the adjustable range measuring unit.

And S120, outputting a first voltage value within a set time length after the target measuring range of the adjustable range measuring unit is determined.

In the voltage measuring device, the fixed gain amplifier and the first analog-to-digital converter are connected to form a maximum measuring range measuring unit, the fixed gain amplifier scales the signal to be measured by a fixed multiple, and the first analog-to-digital converter measures the voltage of the signal to be measured after the fixed gain amplifier scales and outputs a first measured voltage value. Meanwhile, the adjustable gain amplifier and the second analog-to-digital converter are connected to form an adjustable range measuring unit, the adjustable gain amplifier scales the signal to be measured by an adjustable multiple, and the second analog-to-digital converter measures the voltage of the signal to be measured after the adjustable gain amplifier scales and outputs a second measured voltage value. Because the adjustable multiple corresponds to one of the multiple measuring ranges of the adjustable range measuring unit and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit, the adjustable range measuring unit can realize the accurate measurement of the voltage in a small range, and the maximum range measuring unit can realize the rough measurement of the voltage in the maximum range. When the first voltage value is within the maximum measuring range of the adjustable range measuring unit, the target measuring range of the adjustable range measuring unit can be determined, and the adjustable gain amplifier is controlled to adjust the adjustable multiple to be corresponding to the target measuring range, so that the measuring range of the adjustable range measuring unit can be automatically switched. When the adjustable gain amplifier adjusts the adjustable multiple or the scaled signal to be measured is outside the measurement range of the second analog-to-digital converter, the second voltage value measured by the adjustable range measurement unit is inaccurate, and the processor outputs the first voltage value at the moment, so that the continuity of voltage measurement can be maintained and the measurement result is accurate under the condition that the measurement of the adjustable range measurement unit is inaccurate.

Illustratively, the fixed gain amplifier 10 is an LTC6431-15 type amplifier, or an LTC6430-15 type amplifier, or an amplifying chip LM 324.

Illustratively, the adjustable Gain Amplifier 11 is a Programmable Gain Amplifier (PGA). Preferably, the adjustable gain amplifier 11 may be one of an MCP6S21 chip, an MCP6S22 chip, an MCP6S26 chip and an MCP6S28 chip manufactured by Microchip corporation of usa, or one of an AD8321 chip and an AD8250 chip manufactured by Analog Devices of Analog instruments corporation of usa.

Illustratively, the first analog-to-digital converter 20 and the second analog-to-digital converter 21 may be one of ADCs 0808, AD7678, AD9221, AD9223, and AD 9220.

Illustratively, the Processor 30 may be a Central Processing Unit (CPU), and may be one of other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, and the like. The general purpose processor may be a microprocessor or any conventional processor.

In one embodiment, as shown in FIG. 3, processor 30 is configured to perform the following steps:

s200, judging whether the first voltage value is in the maximum measuring range of the adjustable measuring range measuring unit. If the first voltage value is within the maximum measuring range of the adjustable-range measuring unit, executing step S220; if the first voltage value is outside the maximum measuring range of the adjustable-range measuring unit, step S210 is executed.

Specifically, the processor 30 is configured to determine whether the first voltage value is greater than an upper limit value of the maximum measurement range of the adjustable-range measurement unit or less than a lower limit value of the maximum measurement range of the adjustable-range measurement unit; if the first voltage value is larger than the upper limit value of the maximum measuring range of the adjustable range measuring unit or smaller than the lower limit value of the maximum measuring range of the adjustable range measuring unit, determining that the first voltage value is outside the maximum measuring range of the adjustable range measuring unit; and if the first voltage value is smaller than the upper limit value of the maximum measuring range of the adjustable range measuring unit and larger than the lower limit value of the maximum measuring range of the adjustable range measuring unit, determining that the first voltage value is in the maximum measuring range of the adjustable range measuring unit.

S210, outputting a first voltage value.

Specifically, after step S210 is performed, step S200 is performed again. Namely, after the first voltage value measured at the first moment is output, whether the first voltage value measured at the second moment is within the maximum measuring range of the adjustable range measuring unit is determined. Wherein the second time is after the first time.

Specifically, after the first voltage value is output, a new signal to be measured is received, and at this time, it may be determined again whether the first voltage value measured by the current maximum measurement range measuring unit is within the maximum measurement range of the adjustable measurement range measuring unit, that is, after step S210 is executed, step S200 is executed again.

And S220, judging whether the second voltage value is in the current measuring range of the adjustable range measuring unit. If the second voltage value is within the current measuring range of the adjustable range measuring unit, executing step S230; if the second voltage value is outside the current measuring range of the adjustable range measuring unit, step S240 is executed.

In particular, the processor 30 is configured to determine a proportion of the second voltage value in the current measurement range of the second analog-to-digital converter 21. When the proportion of the second voltage value in the current measuring range of the second analog-to-digital converter 21 is between the upper proportion limit and the lower proportion limit, the second voltage value is determined to be in the current measuring range of the adjustable range measuring unit. And when the proportion of the second voltage value in the current measuring range of the second analog-to-digital converter 21 is greater than the upper proportion limit or less than the lower proportion limit, determining that the second voltage value is out of the current measuring range of the adjustable range measuring unit.

And S230, determining the target measuring range of the adjustable range measuring unit according to the second voltage value.

Specifically, the processor 30 is configured to determine a second ratio of the second voltage value in each measurement range of the adjustable-range measurement unit; screening out a second proportion which is smaller than the upper proportion limit and larger than the lower proportion limit; determining the measuring range corresponding to the maximum ratio in the screened second ratio as the target measuring range of the adjustable measuring unit; the upper limit of the proportion is a judgment reference for determining whether the second voltage value exceeds the upper limit of the measuring range of the adjustable range measuring unit; the lower limit of the proportion is a judgment reference for determining whether the second voltage value is lower than the lower limit of the measuring range of the adjustable range measuring unit.

And S240, determining the target measuring range of the adjustable range measuring unit according to the first voltage value.

Specifically, the processor 30 is configured to determine a first ratio of the first voltage value in each measurement range of the adjustable-range measurement unit; screening out a first proportion which is smaller than the upper limit of the proportion and larger than the lower limit of the proportion; and determining the measuring range corresponding to the maximum ratio in the screened first ratio as the target measuring range of the adjustable measuring unit. The upper limit of the proportion is a judgment reference for determining whether the second voltage value exceeds the upper limit of the measuring range of the adjustable range measuring unit; the lower limit of the proportion is a judgment reference for determining whether the second voltage value is lower than the lower limit of the measuring range of the adjustable range measuring unit.

And S250, controlling the adjustable gain amplifier to adjust the adjustable multiple to correspond to the target measuring range of the adjustable range measuring unit.

And S260, outputting a first voltage value within a set time length after the target measuring range of the adjustable range measuring unit is determined.

Illustratively, the set time length is longer than the maximum time required for the adjustable gain amplifier 11 to adjust the adjustable multiple to correspond to the target measurement range of the adjustable range measurement unit. For example, the action time of the adjustable gain amplifier 11 for switching the gain stage is 3 milliseconds, and the set time period may be 5 milliseconds in order to ensure that the action of the adjustable gain amplifier 11 for switching the gain stage is completed.

And S270, judging whether the second voltage value is in the target measuring range of the adjustable range measuring unit and whether the target measuring range is the minimum measuring range of all the measuring ranges of the second voltage value or not outside the set duration after the target measuring range of the adjustable range measuring unit is determined. If the second voltage value is outside the target measurement range of the adjustable range measurement unit, or the target measurement range is not the minimum measurement range of all measurement ranges of the second voltage value, executing step S200; if the second voltage value is within the target measuring range of the adjustable-range measuring unit and the target measuring range is the minimum measuring range of all measuring ranges of the second voltage value, step S280 is executed.

Specifically, the step of judging whether the second voltage value is outside the target measurement range of the adjustable range measurement unit includes the following steps: dividing the difference value between the second voltage value and the minimum value of the measuring range of the adjustable range measuring unit by the difference value between the maximum value and the minimum value of the measuring range of the adjustable range measuring unit to determine the proportion of the second voltage value in the measuring range of the adjustable range measuring unit; when the proportion of the second voltage value in the current measuring range of the adjustable range measuring unit is between the upper proportion limit and the lower proportion limit, determining that the second voltage value is in the current measuring range of the adjustable range measuring unit; and when the proportion of the second voltage value in the current measuring range of the adjustable range measuring unit is larger than the upper limit of the proportion or smaller than the lower limit of the proportion, determining that the second voltage value is out of the current measuring range of the adjustable range measuring unit.

Judging whether the target measuring range is the minimum measuring range in all measuring ranges of the second voltage value or not, comprising the following steps: dividing the difference value between the second voltage value and the minimum value of the measuring range of each measurable second voltage value of the adjustable range measuring unit by the difference value between the corresponding maximum value and the corresponding minimum value of the measuring range respectively, and determining the proportion of the second voltage value in the measuring range of each measurable second voltage value of the adjustable range measuring unit; if the measuring range corresponding to the maximum proportion of the second voltage values in the proportion occupied in the measuring ranges of the second voltage values measurable by the adjustable range measuring unit is not the target measuring range, determining that the target measuring range is not the minimum measuring range in all measuring ranges of the second voltage values; and if the measuring range corresponding to the maximum proportion of the second voltage values in the proportion of the measuring ranges of the second voltage values which can be measured in each adjustable range measuring unit is the target measuring range, determining that the target measuring range is the minimum measuring range of all the measuring ranges of the second voltage values.

Specifically, in the measurement range of the adjustable range measurement unit, in which the second voltage value can be measured, the measurement range in which the proportion of the second voltage value is the largest is the minimum measurement range in which the second voltage value can be measured. The measured second voltage value is already the most accurate value that can be measured by the voltage measuring device.

And S280, outputting a second voltage value.

Specifically, after step S280 is performed, step S270 is performed. After the second voltage value measured at the first moment is output, determining whether the second voltage value measured at the second moment is in the target measuring range or not, and whether the target measuring range is the minimum measuring range of all measuring ranges of the second voltage value measured at the second moment or not; wherein the second time is after the first time.

In this embodiment, first, it is determined whether the first voltage value is within the maximum measurement range of the adjustable range measurement unit, and if not, it indicates that the adjustable range measurement unit cannot measure the signal to be measured, and only the first voltage value measured by the maximum range measurement unit is accurate, so that the first voltage value is directly output. And then receiving the voltage signal to be measured at the next moment, and judging whether the voltage signal to be measured at the next moment is within the maximum measuring range of the adjustable measuring range measuring unit again.

If the first voltage value is within the maximum measuring range of the adjustable range measuring unit, whether the second voltage value is within the current measuring range of the adjustable range measuring unit is further judged, and if the second voltage value is not within the current measuring range of the adjustable range measuring unit, the second voltage value is inaccurate, so that the target measuring range of the adjustable range measuring unit is determined according to the first voltage value, the target measuring range can be adjusted in all ranges of the range measuring unit, and the first voltage value can be measured and does not exceed the minimum measuring range of the range.

If the second voltage value is within the current measuring range of the adjustable range measuring unit, the second voltage value is accurate at the moment, so that the target measuring range of the adjustable range measuring unit is determined according to the second voltage value, and the target measuring range can measure the second voltage value in all ranges of the adjustable range measuring unit and does not exceed the minimum range of the range.

After the target measuring range is determined, the adjustable gain amplifier is controlled to adjust the adjustable multiple to be corresponding to the target measuring range, namely, the current measuring range is switched to the target measuring range.

And then, outputting the first voltage value within a set time length after the target measuring range is determined, so that the voltage can still be measured in the process of controlling the adjustable gain amplifier to switch the measuring range by the processor.

And then judging whether the second voltage value is in the target measuring range of the adjustable range measuring unit or not and whether the target measuring range is the minimum measuring range of all measuring ranges of the second voltage value or not outside the set time length after the target measuring range is determined, wherein if the second voltage value is outside the target measuring range of the adjustable range measuring unit or the target measuring range is not the minimum measuring range of all measuring ranges of the second voltage value, the second voltage value is inaccurate at the moment, or the second voltage value can be measured by using the smaller measuring range of the adjustable range measuring unit, namely the measuring precision of the current second voltage value is higher, the current second voltage value is not adopted, and the current first voltage value is judged again whether to be in the maximum measuring range of the adjustable range measuring unit or not. If the second voltage value is within the target measuring range of the adjustable range measuring unit and the target measuring range is the minimum measuring range of all measuring ranges of the second voltage value, it represents that the second voltage value at the moment is the most accurate value which can be measured by the voltage measuring device, so the second voltage value is output.

The time of the set time length is set to be longer than the longest time of the switching range, so that the adjustable gain amplifier is ensured to complete the range switching action after the set time length.

The device can automatically switch the measuring range according to the signal to be measured, the signal to be measured does not exceed the minimum measuring range of the measuring range and the range, namely the device can measure the most accurate measuring range of the signal to be measured. Therefore, the range can be automatically switched to the optimal range according to the signal to be measured, the measurement accuracy is ensured, when the adjustable gain amplifier adjusts the adjustable multiple or the scaled signal to be measured is out of the measurement range of the second analog-to-digital converter, the second voltage value measured by the adjustable range measurement unit is inaccurate, the processor outputs the first voltage value at the moment, the continuity of voltage measurement can be maintained under the condition that the measurement of the adjustable range measurement unit is inaccurate, and the measurement result is accurate.

Specifically, the processor 30 is configured to determine a ratio of the second voltage value in the measurement range of the second analog-to-digital converter 21; when the proportion of the second voltage value in the measurement range of the second analog-to-digital converter 21 is between the upper proportion limit and the lower proportion limit, determining that the signal to be measured after the adjustable gain amplifier 11 is scaled is in the measurement range of the second analog-to-digital converter 21; when the proportion of the second voltage value in the measurement range of the second analog-to-digital converter 21 is greater than the upper limit of the proportion or less than the lower limit of the proportion, determining that the signal to be measured after the scaling of the adjustable gain amplifier 11 is outside the measurement range selected by the second analog-to-digital converter 21.

In such a way, whether the signal to be measured after the adjustable gain amplifier is zoomed is out of the measuring range of the second analog-to-digital converter or not is judged, so that whether the adjustable gain amplifier exceeds the measuring range or not is determined, and whether the second voltage value output by the adjustable gain amplifier is reliable and accurate or not is determined.

The second voltage value is, for example, a ratio of the second voltage value to the measurement range of the second analog-to-digital converter 21, which is a difference between the second voltage value and the minimum value of the measurement range of the second analog-to-digital converter 21, divided by a difference between the maximum value and the minimum value of the measurement range of the second analog-to-digital converter 21.

In one embodiment, as shown in fig. 4, the processor 30 is further configured to take the first upper scale limit as the upper scale limit and the first lower scale limit as the lower scale limit when the second voltage value is gradually increased; and when the second voltage value is gradually reduced, taking the second proportion upper limit as the proportion upper limit, taking the second proportion lower limit as the proportion lower limit, wherein the second proportion upper limit is smaller than the first proportion upper limit, and the second proportion lower limit is smaller than the first proportion lower limit.

Taking fig. 4 as an example, Vth1+ represents a first upper ratio limit, Vth0+ represents a second upper ratio limit, Vth 0-represents a first lower ratio limit, and Vth 1-represents a second lower ratio limit. As shown in fig. 4, the first upper ratio limit Vth1+ is greater than the second upper ratio limit Vth0+, and the first lower ratio limit Vth 0-is greater than the second lower ratio limit Vth 1-.

The arrows in fig. 4 represent the trend of the voltage change, and the solid line indicates the selected upper or lower proportional limit.

When the second voltage value gradually increases, the first upper scale limit Vth1+ is selected as the upper scale limit as shown in the upper left diagram in fig. 4, and the first lower scale limit Vth 0-is selected as the lower scale limit as shown in the lower right diagram in fig. 4.

When the second voltage value gradually decreases, as shown in the upper right diagram in fig. 4, the second upper scale limit Vth0+ is selected as the upper scale limit, and as shown in the lower left diagram in fig. 4, the second lower scale limit Vth 1-is selected as the lower scale limit.

Specifically, the second voltage value gradually increases, that is, the second voltage value at the next time is greater than the second voltage value at the previous time within the set time period. The second voltage value gradually decreases, that is, the second voltage value at the next moment is smaller than the second voltage value at the previous moment in the set time length.

Illustratively, the processor 30 includes a hysteresis comparator for changing the upper scale limit of the processor 30 to a first upper scale limit and the lower scale limit to a first lower scale limit when the voltage value is gradually increased, and changing the upper scale limit of the processor 30 to a second upper scale limit and the lower scale limit to a second lower scale limit when the voltage value is gradually decreased.

Illustratively, the first proportion upper limit, the first proportion lower limit, the second proportion upper limit and the second proportion lower limit are determined according to an actual noise value of the voltage signal to be measured.

In this embodiment, when the voltage value gradually increases, the upper proportional limit and the lower proportional limit of the processor are changed to the first upper proportional limit and the first lower proportional limit, and when the voltage value gradually decreases, the upper proportional limit and the lower proportional limit of the processor are changed to the second upper proportional limit and the second lower proportional limit, respectively. The first upper proportion limit, the first lower proportion limit, the second upper proportion limit and the second lower proportion limit are determined according to an actual noise value. Therefore, when the voltage value acquired by the analog-to-digital converter is noisy, the voltage fluctuation caused by the noise can be covered by the hysteresis width, so that the influence of the noise on the processor in judging whether the second analog-to-digital converter exceeds the measuring range is avoided, the frequent replacement and selection of the output voltage value due to the influence of the noise of the processor is avoided, and the output voltage value of the processor is more stable.

In one embodiment, as shown in fig. 5, there is provided a voltage measurement method including:

step S402, zooming the signal to be measured by a fixed multiple through a fixed gain amplifier, and measuring the zoomed signal to be measured of the fixed gain amplifier through a first analog-to-digital converter to obtain a first voltage value; the fixed gain amplifier and the first analog-to-digital converter are connected to form a maximum measuring range measuring unit.

Illustratively, the voltage measurement signal is amplified by a factor of 10 using a proportional amplifier (LM324) circuit.

Step S404, the signal to be measured is zoomed by adjustable multiple through an adjustable gain amplifier, and the zoomed signal to be measured of the adjustable gain amplifier is measured through a second analog-to-digital converter to obtain a second voltage value; the adjustable gain amplifier and the second analog-to-digital converter are connected to form an adjustable range measuring unit, the adjustable multiple corresponds to one of a plurality of measuring ranges of the adjustable range measuring unit, and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit.

Step S406, when the first voltage value is within the maximum measuring range of the adjustable range measuring unit, determining the target measuring range of the adjustable range measuring unit; and controlling the adjustable gain amplifier to adjust the adjustable multiple to correspond to the target measuring range of the adjustable range measuring unit.

Step S408, outputting a first voltage value within a set time length after the target measuring range of the adjustable range measuring unit is determined.

In this embodiment, a fixed gain amplifier and a first analog-to-digital converter are connected to form a maximum measurement range unit, the fixed gain amplifier scales a signal to be measured by a fixed multiple, and the first analog-to-digital converter measures a voltage of the signal to be measured after the fixed gain amplifier scales and outputs a first measured voltage value. Meanwhile, the adjustable gain amplifier and the second analog-to-digital converter are connected to form an adjustable range measuring unit, the adjustable gain amplifier scales the signal to be measured by an adjustable multiple, and the second analog-to-digital converter measures the voltage of the signal to be measured after the adjustable gain amplifier scales and outputs a second measured voltage value. Because the adjustable multiple corresponds to one of the multiple measuring ranges of the adjustable range measuring unit and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit, the adjustable range measuring unit can realize the accurate measurement of the voltage in a small range, and the maximum range measuring unit can realize the rough measurement of the voltage in the maximum range. When the first voltage value is within the maximum measuring range of the adjustable range measuring unit, the target measuring range of the adjustable range measuring unit can be determined, and the adjustable gain amplifier is controlled to adjust the adjustable multiple to be corresponding to the target measuring range, so that the measuring range of the adjustable range measuring unit can be automatically switched. When the adjustable gain amplifier adjusts the adjustable multiple or the scaled signal to be measured is outside the measurement range of the second analog-to-digital converter, the second voltage value measured by the adjustable range measurement unit is inaccurate, and the processor outputs the first voltage value at the moment, so that the continuity of voltage measurement can be maintained and the measurement result is accurate under the condition that the measurement of the adjustable range measurement unit is inaccurate.

It should be understood that although the various steps in the flowcharts of fig. 2-3, 5 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in fig. 2-3, 5 may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed in turn or alternatively with other steps or at least some of the other steps.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database or other medium used in the embodiments provided herein can include at least one of non-volatile and volatile memory. Non-volatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical storage, or the like. Volatile Memory can include Random Access Memory (RAM) or external cache Memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others.

In the description herein, references to the description of "some embodiments," "other embodiments," "desired embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, a schematic description of the above terminology may not necessarily refer to the same embodiment or example.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A voltage measurement device, the device comprising:

the maximum measuring range measuring unit comprises a fixed gain amplifier (10) and a first analog-to-digital converter (20) which are connected; the fixed gain amplifier (10) is used for scaling a signal to be measured by a fixed multiple, and the first analog-to-digital converter (20) is used for measuring the voltage of the signal to be measured after scaling by the fixed gain amplifier (10) and outputting a first voltage value obtained by measurement;

the adjustable range measuring unit comprises an adjustable gain amplifier (11) and a second analog-to-digital converter (21) which are connected; the adjustable gain amplifier (11) is used for scaling the signal to be measured by an adjustable multiple, and the second analog-to-digital converter (21) is used for measuring the voltage of the signal to be measured after the adjustable gain amplifier (11) is scaled and outputting a second voltage value obtained through measurement; the adjustable multiple corresponds to one of a plurality of measuring ranges of the adjustable range measuring unit, and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit;

a processor (30) connected to the first analog-to-digital converter (20), the adjustable gain amplifier (11) and the second analog-to-digital converter (21), respectively, for determining a target measurement range of the adjustable range measurement unit when the first voltage value is within a maximum measurement range of the adjustable range measurement unit; controlling the adjustable gain amplifier (11) to adjust the adjustable multiple to correspond to the target measuring range; and outputting the first voltage value within the set time length after the target measuring range is determined.

2. The apparatus of claim 1 wherein the processor (30) is configured to determine a target measurement range of the adjustable range measurement unit based on the first voltage value when the second voltage value is outside a current measurement range of the adjustable range measurement unit; and when the second voltage value is within the current measuring range of the adjustable range measuring unit, determining the target measuring range of the adjustable range measuring unit according to the second voltage value.

3. The apparatus of claim 2 wherein the processor (30) is configured to determine a first proportion of the first voltage value in each measurement range of the adjustable range measurement unit; screening out the first proportion which is smaller than the upper proportion limit and larger than the lower proportion limit; determining the measuring range corresponding to the maximum proportion in the screened first proportion as the target measuring range of the adjustable measuring range measuring unit; or, determining a second proportion of the second voltage value in each measuring range of the adjustable range measuring unit; screening out the second proportion which is smaller than the upper proportion limit and larger than the lower proportion limit; determining the measuring range corresponding to the maximum proportion in the screened second proportion as the target measuring range of the adjustable measuring range measuring unit; the upper limit of the proportion is a judgment reference for determining whether the second voltage value exceeds the upper limit of the measuring range of the adjustable range measuring unit; the lower proportional limit is a criterion for determining whether the second voltage value is lower than the lower measuring range limit of the adjustable measuring range measuring unit.

4. The apparatus of claim 2, wherein the processor (30) is configured to determine a proportion of the second voltage value in a current measurement range of the second analog-to-digital converter (21); when the proportion of the second voltage value in the current measuring range of the second analog-to-digital converter (21) is between a proportion upper limit and a proportion lower limit, determining that the second voltage value is in the current measuring range of the adjustable range measuring unit; and when the proportion of the second voltage value in the current measuring range of the second analog-to-digital converter (21) is larger than the upper proportion limit or smaller than the lower proportion limit, determining that the second voltage value is out of the current measuring range of the adjustable range measuring unit.

5. The apparatus of claim 4, wherein the processor (30) is configured to, when the second voltage value increases gradually, take a first upper scale limit as the upper scale limit and a first lower scale limit as the lower scale limit; and when the second voltage value is gradually reduced, taking a second proportion upper limit as the proportion upper limit, taking a second proportion lower limit as the proportion lower limit, wherein the second proportion upper limit is smaller than the first proportion upper limit, and the second proportion lower limit is smaller than the first proportion lower limit.

6. The device according to any one of claims 1 to 5, wherein the processor (30) is configured to output the first voltage value measured at a first time when the first voltage value measured at the first time is outside the maximum measurement range of the adjustable range measurement unit; determining whether the first voltage value measured at the second moment is within the maximum measuring range of the adjustable range measuring unit; wherein the second time is after the first time.

7. The device according to any one of claims 1 to 5, wherein the set time period is longer than the maximum time required for the adjustable gain amplifier (11) to adjust the adjustable multiple to correspond to the target measurement range.

8. The apparatus of any one of claims 1 to 5, wherein the processor (30) is configured to output the second voltage value measured at the first time when the second voltage value measured at the first time is within the target measurement range and the target measurement range is a minimum measurement range of all measurement ranges of the second voltage value measured at the first time, outside the set duration after the target measurement range is determined; determining whether the second voltage value measured at the second moment is within the target measuring range or not, and whether the target measuring range is the minimum measuring range of all measuring ranges of the second voltage value measured at the second moment or not; wherein the second time is after the first time.

9. The apparatus of any of claims 1 to 5 wherein the processor (30) is configured to determine whether the first voltage value is within a maximum measurement range of the adjustable range measurement unit outside a set duration after the target measurement range is determined, when the second voltage value is outside the target measurement range, or when the target measurement range is not a minimum measurement range of all measurement ranges of the second voltage value.

10. A method of voltage measurement, the method comprising:

zooming a signal to be measured by a fixed gain amplifier by a fixed multiple, and measuring the zoomed signal to be measured of the fixed gain amplifier by a first analog-to-digital converter to obtain a first voltage value; the fixed gain amplifier and the first analog-to-digital converter are connected to form a maximum measuring range measuring unit;

the signal to be measured is zoomed by an adjustable gain amplifier by an adjustable multiple, and the zoomed signal to be measured of the adjustable gain amplifier is measured by a second analog-to-digital converter to obtain a second voltage value; the adjustable gain amplifier and the second analog-to-digital converter are connected to form an adjustable range measuring unit, the adjustable multiple corresponds to one of a plurality of measuring ranges of the adjustable range measuring unit, and each measuring range of the adjustable range measuring unit is really contained in the measuring range of the maximum range measuring unit;

when the first voltage value is within the maximum measuring range of the adjustable range measuring unit, determining the target measuring range of the adjustable range measuring unit;

controlling the adjustable gain amplifier to adjust the adjustable multiple to correspond to the target measuring range;

and outputting the first voltage value within a set time length after the target measuring range of the adjustable range measuring unit is determined.

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