CN111896804A - Measuring equipment and method - Google Patents
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- CN111896804A CN111896804A CN202010638408.7A CN202010638408A CN111896804A CN 111896804 A CN111896804 A CN 111896804A CN 202010638408 A CN202010638408 A CN 202010638408A CN 111896804 A CN111896804 A CN 111896804A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/02—Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/02—Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time or duration
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Abstract
The present invention provides a measuring apparatus comprising: the first measuring circuit is used for acquiring a frequency signal according to an input signal; the second measuring circuit is used for acquiring a duty ratio signal according to the input signal; the switching circuit is connected with the second measuring circuit; the control circuit is connected with the switch circuit and is used for controlling the switch circuit to be coupled with or disconnected from the second measuring circuit; and the input end of the processing circuit is connected with the first measuring circuit and the second measuring circuit, and the processing circuit is used for processing the frequency signal or the duty ratio signal output by the first measuring circuit or the second measuring circuit to obtain the frequency value of the frequency signal or the duty ratio value of the duty ratio signal. According to the measuring device of the embodiment of the invention, the frequency signal for measuring the frequency and the duty ratio signal for measuring the duty ratio can be respectively obtained, corresponding values are finally obtained, and finally, the distinguishing and the identification of the frequency and the duty ratio signal types are realized so as to improve the measuring accuracy.
Description
Technical Field
The invention relates to the field of general measurement, in particular to measuring equipment and a measuring method.
Background
The measurement of the frequency and the duty ratio of the signal has a very important meaning for analyzing the signal, the frequency of the signal is also called as a frequency signal, which refers to the change time of the signal in a period, the duty ratio represents the percentage of a positive peak or a negative peak of a waveform in the period, and a universal meter is generally adopted to measure the frequency and the duty ratio of the signal.
The multimeter needs to introduce a signal shaping technology for measuring the signals, and the signal shaping technology goes through the processes from an original external trigger circuit to operational amplifier shaping through the development of the last two decades until the current ADC + MCU technology evolves. The external trigger circuit adopts the core principle that a monostable trigger technology is adopted, and frequency and duty ratio measurement is completed through a Schmidt trigger; with the development of the multimeter industry, besides the monostable contactor technology, some time-base trigger circuits and operational amplifier circuits are adopted to realize frequency shaping measurement, and at present, the technologies are already integrated into an integrated digital multimeter. With the development of chip integration technology, the original external monostable and time-base triggering processing technologies have been integrated into a whole, namely, the high-speed ADC + MCU technology is adopted.
However, in the process of implementing the technical scheme of the invention in the embodiment of the present application, the inventor of the present application finds that the above-mentioned technologies, whether the technologies are external circuits, shaping processing technologies or integrated ADC processing technologies, have the problem of accuracy in frequency measurement and duty ratio measurement, and how to ensure that the measurement of the frequency signal and the duty ratio signal is more accurate becomes a problem that needs to be solved together in the instrument industry at present.
Disclosure of Invention
In view of the above-mentioned problem of poor accuracy of frequency measurement and duty cycle measurement, the present invention has been made in order to provide a measuring apparatus and method that overcome or at least partially solve the above-mentioned problem.
According to an aspect of the present invention, there is provided a measuring apparatus comprising:
the first measuring circuit is used for acquiring a frequency signal according to an input signal;
the second measuring circuit is used for acquiring a duty ratio signal according to the input signal;
a switching circuit connected to the second measurement circuit;
the control circuit is connected with the switch circuit and is used for controlling the switch circuit to be coupled with or disconnected from the second measuring circuit;
and the input end of the processing circuit is connected with the first measuring circuit and the second measuring circuit, and the processing circuit is used for processing the frequency signal or the duty ratio signal output by the first measuring circuit or the second measuring circuit to obtain the frequency value of the frequency signal or the duty ratio value of the duty ratio signal.
Optionally, the measurement device, wherein:
when the control circuit outputs a first level, the switching circuit is disconnected from the second measurement circuit, and the processing circuit is coupled to the first measurement circuit;
when the control circuit outputs a second level, the switching circuit is coupled to the second measurement circuit and the processing circuit is coupled to the switching circuit.
Optionally, the measuring apparatus further includes:
a display component coupled to the control circuit, the display component configured to receive and display a frequency value or a duty cycle value of the input signal accordingly; wherein,
the control circuit is coupled to the output of the processing circuit for receiving the frequency value or duty cycle value of the input signal output by the processing circuit.
Optionally, the measuring apparatus further includes:
and the input component is connected with the control circuit and is configured to receive input information of a user and instruct the control circuit to output a first level or a second level according to the input information.
Optionally, in the measurement apparatus:
the first measurement circuit includes a capacitance and the second measurement circuit includes a first resistance, the capacitance being in parallel with the first resistance.
Optionally, the device further includes a transistor, and the control circuit controls the switching circuit to be coupled to or disconnected from the second measurement circuit through the transistor.
The invention also comprises a measurement method applied to a multimeter having an input port, wherein the method comprises:
receiving an operation instruction, wherein the operation instruction represents that an input signal is measured to obtain a parameter value;
determining a measurement parameter in response to the operating instruction;
coupling the input port to an input of a first measurement circuit or a second measurement circuit according to the measurement parameter; the first measurement circuit is different from the second measurement circuit;
and controlling the output end of the first measuring circuit or the second measuring circuit to be coupled with a processing circuit so that the processing circuit obtains a parameter value according to the signal output by the first measuring circuit or the second measuring circuit.
Optionally, in the measurement method, determining the measurement parameter in response to the operation instruction includes:
judging whether the operation instruction is a first instruction or not, if so, the measurement parameter is a frequency parameter;
if not, the measurement parameter is a duty ratio parameter.
Optionally, in the measuring method, coupling the input port to an input terminal of a first measuring circuit or a second measuring circuit according to the measurement parameter includes:
when the measurement parameter is a frequency parameter, outputting a first level to control the input signal to enter the first measurement circuit through the input port;
and when the measurement parameter is a duty cycle parameter, outputting a second level to control the input signal to enter the second measurement circuit through the input port.
Optionally, in the measuring method, outputting the second level to control the input signal to pass through the second measuring circuit includes:
based on the second level, controlling a switching circuit to be coupled with the second measurement circuit to cause the input signal to enter the second measurement circuit via the input port.
According to the measuring equipment and the measuring method, the frequency signal for measuring the frequency and the duty ratio signal for measuring the duty ratio can be respectively obtained, the difference is that in the prior art, only frequency measurement or duty ratio measurement can be carried out on a single input signal, and finally, the frequency and duty ratio signal types are distinguished and identified so as to improve the measuring accuracy.
The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, 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 an external configuration of a multimeter incorporating a measurement device according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of the measuring apparatus according to the embodiment of the present invention;
FIG. 3 is a schematic diagram of a circuit relationship of the measurement apparatus according to an embodiment of the present invention;
fig. 4 is a flowchart of the measurement method according to the embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The application aims at providing the measuring equipment capable of measuring different parameters, and the measuring equipment is arranged on the universal meter. Referring to FIG. 1, a multimeter incorporating a measurement device according to various embodiments of the present invention includes: the test device comprises a shell 10, an input port 20 and a meter pen 30, wherein the input port is arranged on the shell 10, one end of the meter pen 30 is connected with the input port 20 and a public end, and the other end of the meter pen is connected with a circuit to be tested to obtain an input signal. And the measurement device is integrated inside the multimeter.
The present application is described below with reference to specific embodiments and specific application scenarios.
Referring to fig. 2, a measurement apparatus according to an embodiment of the present invention is provided, including:
a first measurement circuit 201 for acquiring a frequency signal from an input signal;
a second measurement circuit 202, configured to obtain a duty ratio signal according to the input signal;
a switching circuit 203 connected to the second measurement circuit 202;
a control circuit 204 connected to the switch circuit 203 for controlling the switch circuit 203 to be coupled to or decoupled from the second measurement circuit 202;
the input end of the processing circuit 205 is connected to the first measuring circuit 201 and the second measuring circuit 202, and the processing circuit 205 is configured to process the frequency signal or the duty cycle signal output by the first measuring circuit 201 or the second measuring circuit 202 to obtain a frequency value of the frequency signal or a duty cycle value of the duty cycle signal.
The measuring device according to the above embodiment of the present invention may obtain the frequency signal for measuring the frequency and the duty ratio signal for measuring the duty ratio from the first measuring circuit or the second measuring circuit, respectively, and finally obtain the frequency value or the duty ratio value, which is different from the prior art that only a single input signal can be subjected to frequency measurement or duty ratio measurement, and finally realize the distinguishing and identification of the frequency and duty ratio signal types to improve the accuracy of the measurement.
Specifically, one end of the first measurement circuit 201 is connected to the input port, and is configured to obtain an input signal from the input port, and the other end of the first measurement circuit is connected to the processing circuit 205; one end of the second measurement circuit 202 is also connected to the input port, and is also used for acquiring an input signal from the input port; the other end of the input port is connected with a switch circuit 203, namely the input port, the first measuring circuit and the processing circuit are sequentially connected, the input port, the second measuring circuit, the switch circuit and the processing circuit are sequentially connected, and the first measuring circuit is connected with the second measuring circuit in parallel.
The frequency signal output by the input signal after passing through the first measuring circuit 201 can accurately obtain the frequency value of the input signal, the duty ratio signal output by the input signal after passing through the second measuring circuit 202 can accurately obtain the duty ratio value of the input signal, both the first measuring circuit and the second measuring circuit can convert the same input signal into signals containing different components, but it can be determined that the frequency signal output by the first measuring circuit does not change the frequency value of the input signal, and the duty ratio signal output by the second measuring circuit does not change the duty ratio value of the input signal, so that the frequency value of the frequency signal and the duty ratio value of the duty ratio signal can be accurately and conveniently measured, and the finally obtained frequency value and duty ratio value of the input signal are more accurate.
In order to make the first measuring circuit and the second measuring circuit respectively conduct, the switching circuit 203 is mainly used for switching between the first measuring circuit and the second measuring circuit to obtain corresponding frequency values or duty ratios according to different requirements, specifically, one end of the switching circuit is connected to the second measuring circuit, and the other end of the switching circuit is connected to the processing circuit. When the frequency value of the frequency signal needs to be obtained, the switch circuit and the second measuring circuit are disconnected, so that the input signal outputs the frequency signal to the processing circuit after passing through the first measuring circuit.
The control circuit 204 is configured to receive the measurement instruction, determine whether the duty ratio or the frequency of the input signal needs to be measured according to the measurement instruction, and then control the switch circuit 203 to couple the switch circuit to the first measurement circuit or the second measurement circuit after the determination, so that the input signal passes through the corresponding circuit and obtains the frequency signal or the duty ratio signal, respectively, and then obtain the frequency value or the duty ratio value after the measurement.
After the frequency signal or the duty ratio signal is obtained by the first measuring circuit 201 and the second measuring circuit 202, the processing circuit 205 performs signal shaping processing on the frequency signal or the duty ratio signal to finally obtain a frequency value of the frequency signal or a duty ratio value of the duty ratio signal. The specific scheme adopted by the processing circuit 205 may be shaping by an external trigger circuit, or shaping by an operational amplifier, or shaping by an application technology integrating an a/D main chip integrated by an ADC + MCU technology.
In a preferred embodiment of the present invention, after the control circuit 204 determines the purpose to be measured according to the measurement instruction, the specific scheme for coupling the switch circuit to the first measurement circuit or the second measurement circuit by controlling the switch circuit is to couple the switch circuit to the first measurement circuit or the second measurement circuit by outputting different levels, wherein two ends of the switch circuit are coupled to the second measurement circuit and the processing circuit respectively.
Specifically, when the control circuit 204 outputs the first level, the switch circuit is disconnected from the second measurement circuit, and at this time, the switch circuit and the second measurement circuit are disconnected, so that the input signal cannot pass through the second measurement circuit and is output to the processing circuit. Meanwhile, the processing circuit is coupled with the first measuring circuit, and the input signal directly passes through the first measuring circuit and is output to the processing circuit, so that the frequency value of the input signal is obtained.
When the control circuit 204 outputs the second level, the switch circuit is coupled to the second measurement circuit, and the processing circuit is coupled to the switch circuit, so that the output signal can be directly outputted to the processing circuit via the second measurement circuit, and the duty ratio of the input signal can be obtained.
In a preferred embodiment of the present invention, the measuring apparatus further includes:
a display component 206 coupled to the control circuit, the display component configured to receive and display a frequency value or a duty cycle value of the input signal accordingly; wherein the control circuit is coupled to the output of the processing circuit for receiving the frequency value or duty cycle value of the input signal output by the processing circuit. Specifically, when the processing circuit obtains the frequency value or the duty ratio value, the frequency value or the duty ratio value needs to be sent to the control circuit for visual display, and the control circuit drives the display component to display the reading of the frequency value or the duty ratio value.
A measuring apparatus according to a preferred embodiment of the present invention, wherein: the measuring apparatus further includes: an input component 207 connected to the control circuit, the input component configured to receive input information from a user and instruct the control circuit to output the first level or the second level according to the input information. The user is a user of the measuring device, the input information of the user is the measurement requirement of the user, for example, the duty ratio or the frequency of the measurement input signal is measured, and the user provides the input information to the measuring device through the input component to instruct the control circuit to control the coupling or the decoupling of the switching circuit and the second measuring circuit. Namely, the measuring device receives input information of a user through the input assembly and feeds the input information back to the control circuit, so that the control circuit generates corresponding action. The input component may be in the form of a knob or a key, or may be in the form of a touch screen operation, and is not limited to the manner described in the embodiment of the present invention. Wherein the first level is a low level and the second level is a high level.
A measuring apparatus according to a preferred embodiment of the present invention is shown in fig. 3, wherein: in order to ensure mutual isolation between the first measuring circuit and the second measuring circuit, the first measuring circuit comprises a capacitor C8, the second measuring circuit comprises a first resistor R3, and the capacitor C8 is connected with the first resistor R3 in parallel. The main method of frequency measurement is to trigger the input processing circuit through the gate circuit to calculate the pulse period of the frequency, and in the analog electronic circuit, no matter how many frequency circuits such as clock, high frequency, local oscillator, harmonic wave, etc., there are DC components, depending on the size. Therefore, when the duty ratio of the input signal needs to be measured, the second measurement circuit in which the first resistor R3 is located cannot be turned on. In a specific usage scenario of the present invention, when a user provides first input information via an input component (not shown), the first input information representing a frequency value of an input signal, the first measurement circuit comprising a capacitor receives the input signal from the input port 301 and outputs the frequency signal to the processing circuit (not shown). In other words, the input signal can only pass through the capacitor C8 at this time, and the second measuring device in which the first resistor R3 is located is in an open state because it is not yet connected to the switching circuit. The capacitor C8 converts the input signal passing through it into a pure ac signal, and then inputs the symmetrical waveform output by the ac signal into a processing circuit for signal shaping processing to obtain an accurate frequency value, which is the frequency value of the input signal.
When the duty ratio value is obtained by measuring the frequency signal output by the first measuring circuit, the frequency measurement can be normally measured without being affected, but the duty ratio signal is attenuated due to the influence of the capacitor C8, so that the duty ratio measurement value has a larger deviation, particularly 1% -10%, 90% -99%, and especially has a larger difference when the duty ratio reading value is measured to be less than 10%. Thus, in another specific use scenario of the present invention, when a user provides a second input information via an input component (not shown), the second input information indicating that a duty cycle value of the input signal is obtained, a second measurement circuit comprising a first resistor R3 receives the input signal from the input port 301 and outputs a duty cycle signal to the processing circuit. The capacitor C8 and the first resistor R3 are isolated from each other and the input signal can only pass through the first resistor R3, at this time, the capacitor C8 can be regarded as an off state, and the input capacitive reactance in the capacitor C8 can cause negligible attenuation to the signal in the second measurement circuit. After the input signal passes through the first resistor R3, the obtained duty cycle signal is input to the processing circuit for signal shaping processing to obtain an accurate duty cycle value, which is the duty cycle value of the input signal.
Preferably, the capacitance value of the capacitor C8 is 0.1uF, and the resistance value of the first resistor R3 is 10K. The processing circuit is realized by adopting a general DSP processing chip.
A measuring apparatus according to a preferred embodiment of the present invention, wherein: the apparatus also includes a transistor Q1, the control circuit controlling the switching circuit to be coupled to or decoupled from the second measurement circuit via the transistor Q1. Specifically, the base of the transistor Q1 is coupled to the output of the control circuit, and the emitter of the transistor is coupled to the switching circuit.
In a specific implementation scenario of the present invention, when a frequency (Hz) signal needs to be obtained, the control circuit outputs a first level to enable the transistor Q1 and the switch circuit to be in an off state, and meanwhile, the switch circuit and the second measurement circuit are also in an off state, and the frequency signal is obtained by the first measurement circuit where the capacitor C8 is located; when the duty ratio (%) signal is required to be obtained, in order to couple the switching circuit to the second measurement circuit, the control circuit outputs a second level to drive the transistor Q1, and the power is supplied to the switching circuit, so that the switching circuit is coupled to the second measurement circuit, and the attenuation of the input signal caused by the input capacitance of the capacitor C8 can be ignored. Preferably, transistor Q1 is model SS 8050.
In a preferred embodiment, the output terminal of the control circuit is further connected in series with a resistor R4 and then coupled to the base of the transistor Q1, and the size of the resistor R4 is 4.7K. The collector of the triode Q1 is connected with a resistor R5, and the size of the resistor R5 is 2.2K.
In a preferred embodiment, the switch circuit may be one or a combination of two or more of a photoswitch, an analog switch, and a relay with good isolation performance, for example, when the switch circuit is a photoswitch, the photoswitch includes: the light-operated control end is coupled with the control circuit, and the light-operated output end is connected between the processing circuit and the second measuring circuit in series. The light-operated control end can control the opening and closing of the light-operated output end, so that the light-operated switch is coupled with or disconnected from the second measuring circuit, an effective isolation effect is achieved on the first measuring circuit, the interference of any signal passing through the first measuring circuit on the signal passing through the second measuring circuit is prevented, and the light-operated switch has dielectric strength of 3750V and is superior in isolation performance, distributed capacitance and withstand voltage bearing capacity. Preferably, the model of the light-operated switch is 61VY 3. In one embodiment, the photocontrol terminal comprises pins 1 and 2, the photocontrol output terminal comprises pins 3 and 4, pin 1 of the photocontrol terminal is coupled to the emitter of the transistor Q1, and pin 2 of the photocontrol terminal is grounded; pin 3 of the optical control output is coupled to the processing circuit and pin 4 of the optical control output is coupled to the first resistor R3.
According to the measuring device of the embodiment of the present invention, preferably, the measuring device further includes a resistor R1, one end of the resistor R1 is coupled to the first measuring circuit and the second measuring circuit, and the other end thereof is coupled to the input terminal of the processing circuit.
In summary, the measurement device according to the embodiment of the present invention can distinguish and identify the types of the frequency and duty ratio signals, improve the measurement defect of the conventional single input signal processing method, ensure the measurement accuracy of the frequency and duty ratio signals to be improved, and thoroughly solve the application defects of the instrument and meter products.
The embodiment of the present invention further provides a measurement method applied to a multimeter, where the multimeter has an input port, and the process is shown in fig. 4, and includes:
The method of the embodiment of the invention can obtain the required parameter value at the output end, is different from the prior art that only single input signal can be subjected to parameter measurement, and finally realizes the distinguishing and identification of different parameter types so as to improve the measurement accuracy.
In step 401, in the preferred embodiment, the operation command is provided by a user, i.e. a user or operator of the multimeter, the user provides input information through the input component, and the control circuit receives the input information as the operation command, i.e. the operation command includes a command for obtaining a parameter value required. Specifically, the user may input the operation instruction by using a knob, a key, or a touch screen, which is not limited to the scheme described in this embodiment.
In step 402, when an operation instruction provided by a user is received, a measurement parameter may be determined based on parsing the operation instruction. Specifically, the measurement parameters may include: the frequency measurement parameter and the duty ratio measurement parameter, different measurement parameters need to be obtained through different circuits.
After the measurement parameters are determined, step 403 is performed to couple different measurement circuits according to different measurement parameters. For example, when the analyzed measurement parameter is a frequency measurement parameter, the control circuit controls the first measurement circuit to be coupled to the input port, because the first measurement circuit can obtain a corresponding frequency signal, and thus obtain an accurate frequency value; when the analyzed measurement parameter is the duty ratio measurement parameter, the control circuit controls the second measurement circuit to be coupled with the input port, and the second measurement circuit can acquire the duty ratio signal, so that an accurate duty ratio value is acquired.
In a preferred embodiment, the first measurement circuit comprises a capacitor C8, the second measurement circuit comprises a first resistor R3, and the capacitor C8 is connected in parallel with the first resistor R3. The main method of frequency measurement is to trigger the input processing circuit through the gate circuit to calculate the pulse period of the frequency, and in the analog electronic circuit, no matter how many frequency circuits such as clock, high frequency, local oscillator, harmonic wave, etc., there are DC components, depending on the size. Therefore, when the duty ratio of the input signal needs to be measured, the second measurement circuit in which the first resistor R3 is located cannot be turned on.
In step 404, the parameter values include: frequency value or duty cycle value. When the operation command is to obtain a frequency value, the control circuit couples the output end of the corresponding first measurement circuit to the processing circuit, so that the processing circuit obtains the frequency value according to the frequency signal output by the first measurement circuit. When the operation command is to obtain the duty ratio value, the control circuit couples the output end of the corresponding second measuring circuit to the processing circuit, so that the processing circuit obtains the duty ratio value according to the duty ratio signal output by the second measuring circuit. When the operation command is to obtain the duty cycle value of the input signal, the second measurement circuit including the first resistor R3 at this time receives the input signal from the input port 301 and outputs a duty cycle signal to the processing circuit. The capacitor C8 and the first resistor R3 are isolated from each other and the input signal can only pass through the first resistor R3, at this time, the capacitor C8 can be regarded as an off state, and the input capacitive reactance in the capacitor C8 can cause negligible attenuation to the signal in the second measurement circuit. After the input signal passes through the first resistor R3, the obtained duty cycle signal is input to the processing circuit for signal shaping processing to obtain an accurate duty cycle value, which is the duty cycle value of the input signal.
In the measurement method according to the preferred embodiment of the present invention, determining the measurement parameter in response to the operation instruction further includes:
judging whether the operation instruction is a first instruction or not, if so, the measurement parameter is a frequency parameter; the first instruction is an instruction measurement frequency value, so that when the operation instruction is the first instruction of the measurement frequency value, the measurement parameter can be determined to be the frequency parameter directly according to the first instruction.
If not, the measurement parameter is a duty ratio parameter. When only two instructions of measuring frequency and measuring duty cycle are included, then if the operating instruction is not the first instruction, i.e., not the measured frequency value, then the operating instruction may be considered the second instruction, i.e., the instruction measuring duty cycle value. The measured parameter may thus be determined as a duty cycle parameter from the second instruction.
According to the measuring method of the preferred embodiment of the present invention, in step 403, coupling the input port to the input terminal of the first measuring circuit or the second measuring circuit according to the measured parameter includes:
when the measurement parameter is a frequency parameter, the control circuit outputs a first level to control the input signal to enter the first measurement circuit through the input port, and the first measurement circuit obtains the frequency signal and then transfers the frequency signal to the processing circuit for processing;
and when the measurement parameter is a duty cycle parameter, outputting a second level by the control circuit to control the input signal to pass through a second measurement. The input is disconnected and the second of the input ports is entered into the second measurement circuit. And the second measuring circuit obtains the duty ratio signal and then transfers the duty ratio signal to the processing circuit for processing.
In a preferred embodiment, the control circuit outputs different levels depending on the measured parameter. The user is a user of the measuring device, the input information of the user is the measurement requirement of the user, for example, the duty ratio or the frequency of the measurement input signal is measured, and the user provides the input information to the measuring device through the input component to instruct the control circuit to control the coupling or the decoupling of the switching circuit and the second measuring circuit. Namely, the measuring device receives input information of a user through the input assembly and feeds the input information back to the control circuit, so that the control circuit generates corresponding action. The input component may be in the form of a knob or a key, or may be in the form of a touch screen operation, and is not limited to the manner described in the embodiment of the present invention. Wherein the first level is a low level and the second level is a high level.
According to the measuring method in the preferred embodiment of the present invention, outputting the second level to control the input signal via the second measuring circuit comprises:
based on the second level, controlling a switching circuit to be coupled with the second measurement circuit to cause the input signal to enter the second measurement circuit via the input port. The switching circuit is used for switching between the first measuring circuit and the second measuring circuit by controlling the coupling and the decoupling of the second measuring circuit.
In a specific implementation scenario of the present invention, when a frequency (Hz) signal needs to be obtained, the control circuit outputs a first level to enable the switch circuit and the second measurement circuit to be in an off state, and the input signal passes through the first measurement circuit to obtain the frequency signal; in another specific implementation scenario of the present invention, when it is required to obtain the duty ratio (%) signal, in order to couple the switching circuit to the second measurement circuit, the control circuit outputs the second level to couple the switching circuit to the second measurement circuit, and the input signal does not enter the first measurement circuit, and the attenuation of the input signal by the capacitance C8 input capacitance reactance can be ignored.
In a preferred embodiment of the present invention, the control circuit outputs the first level or the second level to control the coupling and decoupling of the transistor and the switching circuit, thereby further controlling the coupling and decoupling of the switching circuit and the second measurement circuit.
In a preferred embodiment, the switch circuit may be one or a combination of two or more of a photoswitch, an analog switch, and a relay with good isolation performance, for example, when the switch circuit is a photoswitch, the photoswitch includes: the light-operated control end is coupled with the control circuit, and the light-operated output end is connected between the processing circuit and the second measuring circuit in series. The light-operated control end can control the opening and closing of the light-operated output end, so that the light-operated switch is coupled with or disconnected from the second measuring circuit, an effective isolation effect is achieved on the first measuring circuit, the interference of any signal passing through the first measuring circuit on the signal passing through the second measuring circuit is prevented, and the light-operated switch has dielectric strength of 3750V and is superior in isolation performance, distributed capacitance and withstand voltage bearing capacity. Preferably, the model of the light-operated switch is 61VY 3. In one embodiment, the photocontrol terminal comprises pins 1 and 2, the photocontrol output terminal comprises pins 3 and 4, pin 1 of the photocontrol terminal is coupled to the emitter of the transistor Q1, and pin 2 of the photocontrol terminal is grounded; pin 3 of the light control output is coupled to the processing circuit, and pin 4 of the light control output is coupled to the second measurement circuit.
In summary, the measurement device according to the embodiment of the present invention can distinguish and identify the types of the frequency and duty ratio signals, improve the measurement defect of the conventional single input signal processing method, ensure the measurement accuracy of the frequency and duty ratio signals to be improved, and thoroughly solve the application defects of the instrument and meter products.
It should be understood that, in various embodiments of the present invention, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.
It should also be understood that, in the embodiment of the present invention, the term "and/or" is only one kind of association relation describing an associated object, and means that three kinds of relations may exist. For example, a and/or B, may represent: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.
Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may also be an electric, mechanical or other form of connection.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment of the present invention.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention essentially or partially contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The principle and the implementation mode of the invention are explained by applying specific embodiments in the invention, and the description of the embodiments is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (10)
1. A measurement device, comprising:
the first measuring circuit is used for acquiring a frequency signal according to an input signal;
the second measuring circuit is used for acquiring a duty ratio signal according to the input signal;
a switching circuit connected to the second measurement circuit;
the control circuit is connected with the switch circuit and is used for controlling the switch circuit to be coupled with or disconnected from the second measuring circuit;
and the input end of the processing circuit is connected with the first measuring circuit and the second measuring circuit, and the processing circuit is used for processing the frequency signal or the duty ratio signal output by the first measuring circuit or the second measuring circuit to obtain the frequency value of the frequency signal or the duty ratio value of the duty ratio signal.
2. A measuring device according to claim 1, wherein:
when the control circuit outputs a first level, the switching circuit is disconnected from the second measurement circuit, and the processing circuit is coupled to the first measurement circuit;
when the control circuit outputs a second level, the switching circuit is coupled to the second measurement circuit and the processing circuit is coupled to the switching circuit.
3. A measuring device according to claim 2, wherein: the measuring apparatus further includes:
a display component coupled to the control circuit, the display component configured to receive and display a frequency value or a duty cycle value of the input signal accordingly; wherein,
the control circuit is coupled to the output of the processing circuit for receiving the frequency value or duty cycle value of the input signal output by the processing circuit.
4. A measuring device according to claim 2, wherein:
the measuring apparatus further includes: and the input component is connected with the control circuit and is configured to receive input information of a user and instruct the control circuit to output a first level or a second level according to the input information.
5. A measuring device according to claim 1, wherein:
the first measurement circuit includes a capacitance and the second measurement circuit includes a first resistance, the capacitance being in parallel with the first resistance.
6. A measuring device according to claim 1, wherein:
the device further comprises a triode, and the control circuit controls the switch circuit to be coupled with or disconnected from the second measuring circuit through the triode.
7. A measurement method for use with a multimeter having an input port, wherein the method comprises:
receiving an operation instruction, wherein the operation instruction represents that an input signal is measured to obtain a parameter value;
determining a measurement parameter in response to the operating instruction;
coupling the input port to an input of a first measurement circuit or a second measurement circuit according to the measurement parameter; the first measurement circuit is different from the second measurement circuit;
and controlling the output end of the first measuring circuit or the second measuring circuit to be coupled with a processing circuit so that the processing circuit obtains a parameter value according to the signal output by the first measuring circuit or the second measuring circuit.
8. The measurement method of claim 7, wherein determining measurement parameters in response to the operational instructions comprises:
judging whether the operation instruction is a first instruction or not, if so, the measurement parameter is a frequency parameter;
if not, the measurement parameter is a duty ratio parameter.
9. The measurement method of claim 8, wherein coupling the input port to an input of a first measurement circuit or a second measurement circuit according to the measurement parameter comprises:
when the measurement parameter is a frequency parameter, outputting a first level to control the input signal to enter the first measurement circuit through the input port;
and when the measurement parameter is a duty cycle parameter, outputting a second level to control the input signal to enter the second measurement circuit through the input port.
10. The measurement method of claim 9, wherein outputting a second level to control the input signal via a second measurement circuit comprises:
based on the second level, controlling a switching circuit to be coupled with the second measurement circuit to cause the input signal to enter the second measurement circuit via the input port.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2411489Y (en) * | 2000-02-22 | 2000-12-20 | 刘哲明 | Logic testing probe with easyly testing frequency and duty ratio function |
| CN102055443A (en) * | 2009-10-30 | 2011-05-11 | 无锡海威半导体科技有限公司 | Duty cycle detection circuit |
| US20110121874A1 (en) * | 2009-11-24 | 2011-05-26 | Masaaki Kaneko | Systems and Methods for PLL Linearity Measurement, PLL Output Duty Cycle Measurement and Duty Cycle Correction |
| US20140219401A1 (en) * | 2013-02-04 | 2014-08-07 | Koby Finkelstein | Rfi mitigation via duty cycle control |
| CN104331340A (en) * | 2014-11-20 | 2015-02-04 | 苏州富欣智能交通控制有限公司 | Watchdog circuit |
| CN104682929A (en) * | 2013-11-28 | 2015-06-03 | 北车大连电力牵引研发中心有限公司 | Pulse signal duty ratio measuring circuit |
| CN106932640A (en) * | 2017-04-28 | 2017-07-07 | 金陵科技学院 | Pulse signal measurement method of parameters and system based on FPGA |
| CN107093357A (en) * | 2017-06-01 | 2017-08-25 | 华东师范大学 | Multifunction teaching integrated signal analysis system |
| CN107942116A (en) * | 2017-12-28 | 2018-04-20 | 优利德科技(中国)有限公司 | A kind of multi-function multimeter and its measuring method with voice control function |
| CN110231535A (en) * | 2019-06-24 | 2019-09-13 | 爱驰汽车有限公司 | A kind of high-tension circuit method for detecting operation state and system |
| CN110426546A (en) * | 2019-08-26 | 2019-11-08 | 上海理工大学 | Wearable AR Multimeter |
| CN110988466A (en) * | 2019-12-11 | 2020-04-10 | 云南大学 | High-precision frequency meter based on double modes |
-
2020
- 2020-07-06 CN CN202010638408.7A patent/CN111896804B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2411489Y (en) * | 2000-02-22 | 2000-12-20 | 刘哲明 | Logic testing probe with easyly testing frequency and duty ratio function |
| CN102055443A (en) * | 2009-10-30 | 2011-05-11 | 无锡海威半导体科技有限公司 | Duty cycle detection circuit |
| US20110121874A1 (en) * | 2009-11-24 | 2011-05-26 | Masaaki Kaneko | Systems and Methods for PLL Linearity Measurement, PLL Output Duty Cycle Measurement and Duty Cycle Correction |
| US20140219401A1 (en) * | 2013-02-04 | 2014-08-07 | Koby Finkelstein | Rfi mitigation via duty cycle control |
| CN104682929A (en) * | 2013-11-28 | 2015-06-03 | 北车大连电力牵引研发中心有限公司 | Pulse signal duty ratio measuring circuit |
| CN104331340A (en) * | 2014-11-20 | 2015-02-04 | 苏州富欣智能交通控制有限公司 | Watchdog circuit |
| CN106932640A (en) * | 2017-04-28 | 2017-07-07 | 金陵科技学院 | Pulse signal measurement method of parameters and system based on FPGA |
| CN107093357A (en) * | 2017-06-01 | 2017-08-25 | 华东师范大学 | Multifunction teaching integrated signal analysis system |
| CN107942116A (en) * | 2017-12-28 | 2018-04-20 | 优利德科技(中国)有限公司 | A kind of multi-function multimeter and its measuring method with voice control function |
| CN110231535A (en) * | 2019-06-24 | 2019-09-13 | 爱驰汽车有限公司 | A kind of high-tension circuit method for detecting operation state and system |
| CN110426546A (en) * | 2019-08-26 | 2019-11-08 | 上海理工大学 | Wearable AR Multimeter |
| CN110988466A (en) * | 2019-12-11 | 2020-04-10 | 云南大学 | High-precision frequency meter based on double modes |
Non-Patent Citations (3)
| Title |
|---|
| 徐薇等: "数字万用表自动测量系统的设计", 《电子测量技术》 * |
| 邓继海等: "综合测试仪数字万用表模块的研究与设计", 《中国仪器仪表》 * |
| 陈辉云等: "基于STM32的智能WiFi万用表设计", 《工业仪表与自动化装置》 * |
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