CN208459485U - A kind of capacitance measurement system - Google Patents
A kind of capacitance measurement system Download PDFInfo
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- CN208459485U CN208459485U CN201821214127.3U CN201821214127U CN208459485U CN 208459485 U CN208459485 U CN 208459485U CN 201821214127 U CN201821214127 U CN 201821214127U CN 208459485 U CN208459485 U CN 208459485U
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Abstract
The utility model discloses a kind of capacitance measurement systems, including testing capacitance, switching group module, control module, management module, switching group module includes first switch, second switch, third switch, 4th switch, the utility model is designed by the connection relationship to each switch in switching group module, make in control module control switch group module is different when switch on and off, the available multiple measurement capacitances to testing capacitance of management module, and utilize preset algorithm, the stray capacitance that the parasitic capacitance of inside that may be present in measurement capacitance and ground wire generate two pole plates of testing capacitance is all filtered out, then the actual capacitance value of testing capacitance is obtained, the utility model does not need additional definite value capacitor, and it is not limited by environmental factor, the actual capacitance value accuracy of obtained testing capacitance is higher.
Description
Technical field
The utility model relates to capacitance measurement fields, more particularly to a kind of capacitance measurement system.
Background technique
The development of capacitive sensing system is always an important field of research in the quite a long time, existing
, many capacitance type sensors are used for physical quantity, such as movement, power, acceleration, torque, position and pressure measurement, these capacitors
Formula sensor requires to carry out small capacitance high-acruracy survey, small to arrive pF rank, and in terms of low capacitance measurement, measurement
The stray capacitance that the parasitic capacitance of circuit and outer bound pair are measured object is all the source of error, therefore eliminates these parasitic capacitances
It is most important in low capacitance measurement field with stray capacitance.
Currently, eliminate parasitic capacitance inside measuring circuit generally by the testing capacitance that will be under identical environment with
Definite value capacitor does difference, to eliminate measuring circuit internal parasitic capacitances, if testing capacitance and definite value capacitor local environment are different
When sample, external environment is that cannot eliminate to the interference (stray capacitance that such as ground wire generates testing capacitance two-plate) of testing capacitance
, error, low measurement accuracy are still had so as to cause measurement result.
Therefore, how to provide a kind of scheme of solution above-mentioned technical problem is that those skilled in the art need to solve at present
Problem.
Utility model content
The purpose of the utility model is to provide a kind of capacitance measurement system, additional definite value capacitor is not needed, and not by environment
Factor limitation, the actual capacitance value accuracy of obtained testing capacitance are higher.
In order to solve the above technical problems, the utility model provides a kind of capacitance measurement system, including testing capacitance, switch
Group module, control module, management module, the switching group module include first switch, and second switch, third switch, the 4th opens
It closes, in which:
The first end of the first switch is connected with the first end that the third switchs, and common end is as the switching group
The first end of module, the second end of the first switch respectively with the first end of the second switch and the testing capacitance
The second end of the connection of one pole plate, the second end of the second switch and the 4th switch is connected to ground, the third switch
Second end connect respectively with the first end of the 4th switch and the second pole plate of the testing capacitance；
It is connect with the control terminal of the switching group module, for being controlled in the switching group module by current control instruction
It is corresponding with current control instruction to close the switch, and control the control module that other switches disconnect；
It is connect with the first end of the switching group module, for obtaining the testing capacitance under current control instruction
Measurement capacitance obtain the reality of the testing capacitance and according to the measurement capacitance under all control instructions got
The management module of capacitance.
Preferably, the management module includes:
For exporting the first square wave of predetermined level, so as to the first square wave unit for the testing capacitance charge/discharge；
First end is connect with the output end of the first square wave unit, the first end of second end and the switching group module connects
It connects, the second square wave unit for exporting the second square wave, wherein the duty ratio of second square wave is filled with the testing capacitance
Electric time/discharge time corresponds；
Input terminal is connect, for second square wave to be converted to DC voltage with the output end of the second square wave unit
The converting unit of value；
It is connect with the output end of the converting unit, for obtaining the DC voltage value, and by the DC voltage value
Be converted to the sampling unit of capacitance, wherein the capacitance is the survey of the testing capacitance under current control instruction
Measure capacitance.
Preferably, the first square wave unit includes the first NAND gate equipped with Schmidt trigger, first capacitor, and first
Resistance, second resistance and diode, in which:
The first end of the first capacitor respectively with the first input end of first NAND gate, first NAND gate
The connection of the first end of second input terminal and the first resistor, the second end ground connection of the first capacitor, first NAND gate
Output end connect respectively with the first end of the second end of the first resistor, the cathode of the diode, the second resistance,
Output end of its common end as the first square wave unit, the anode of the diode respectively with the second resistance second
The connection of the first end of end and the switching group module.
Preferably, the second square wave unit includes the second NAND gate equipped with Schmidt trigger；
The first input end of second NAND gate is connect with the output end of the first square wave unit, described second with it is non-
Second input terminal of door is connect with the first end of the switching group module.
Preferably, the converting unit is low-pass filter.
Preferably, the low-pass filter includes 3rd resistor and the second capacitor, in which:
Input terminal of the first end of the 3rd resistor as the converting unit, the second end of the 3rd resistor and institute
State the first end connection of the second capacitor, output end of the common end as the converting unit, the second end of second capacitor
It is connected to ground.
Preferably, the sampling unit is microcontroller.
Preferably, the first switch, the second switch, third switch, the 4th switch are adg711
Analog switch.
Preferably, the first switch, the second switch, third switch, the 4th switch are relay.
Preferably, the second resistance is the resistance that resistance value is 1M Ω.
The utility model provides a kind of capacitance measurement system, including testing capacitance, switching group module, control module, pipe
Module is managed, switching group module includes first switch, second switch, third switch, the 4th switch, in which: the first of first switch
The first end switched with third is held to connect, first end of the common end as switching group module, the second end difference of first switch
It is connect with the first pole plate of the first end of second switch and testing capacitance, the second end of the second end of second switch and the 4th switch
It is connected to ground, the second end of third switch is connect with the second pole plate of the first end of the 4th switch and testing capacitance respectively；With
The control terminal connection of switching group module, for by current control instruction control switch group module with current control instruction pair
That answers closes the switch, and controls the control module that other switches disconnect；It is connect with the first end of switching group module, for obtaining
The measurement capacitance of testing capacitance under current control instruction, and according to the measurement capacitor under all control instructions got
Value, obtains the management module of the actual capacitance value of testing capacitance.
As it can be seen that in practical applications, using the embodiment of the utility model, passing through the company to each switch in switching group module
The relationship of connecing is designed, and make in control module control switch group module is different when switch on and off, and management module can be with
Multiple measurement capacitances of testing capacitance are got, and utilize preset algorithm, by inside that may be present in measurement capacitance
The stray capacitance that parasitic capacitance and ground wire generate two pole plates of testing capacitance all filters out, and then obtains testing capacitance
Actual capacitance value, the utility model does not need additional definite value capacitor, and is not limited by environmental factor, the reality of obtained testing capacitance
Border capacitance accuracy is higher.
Detailed description of the invention
It, below will be to the prior art and embodiment in order to illustrate more clearly of the technical scheme in the embodiment of the utility model
Needed in attached drawing be briefly described, it should be apparent that, the accompanying drawings in the following description is only the utility model
Some embodiments for those of ordinary skill in the art without creative efforts, can also be according to this
A little attached drawings obtain other attached drawings.
Fig. 1 is a kind of structural schematic diagram of capacitance measurement system provided by the utility model；
Fig. 2 is the structural schematic diagram of another capacitance measurement system provided by the utility model；
Fig. 3 is the structural schematic diagram of another capacitance measurement system provided by the utility model；
Fig. 4 is a kind of input-output wave shape figure of Schmidt trigger provided by the utility model；
Fig. 5 is a kind of waveform diagram of the embodiment of capacitance measurement system provided by the utility model.
Specific embodiment
The core of the utility model is to provide a kind of capacitance measurement system, does not need additional definite value capacitor, and not by environment
Factor limitation, the actual capacitance value accuracy of obtained testing capacitance are higher.
It is practical new below in conjunction with this to keep the objectives, technical solutions, and advantages of the embodiments of the present invention clearer
Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched
The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Based on the implementation in the utility model
Example, every other embodiment obtained by those of ordinary skill in the art without making creative efforts belong to
The range of the utility model protection.
Fig. 1 is please referred to, Fig. 1 is the structural schematic diagram of capacitance measurement system provided by the utility model, including electricity to be measured
Hold Cd, switching group module 1, control module 2, management module 3, switching group module 1 includes first switch 11, second switch 12, and the
Three switches 13, the 4th switch 14, in which:
The first end of first switch 11 is connected with the first end of third switch 13, and common end is as switching group module 1
First end, the second end of first switch 11 respectively with the first end of second switch 12 and testing capacitance CdThe first pole plate connection,
The second end of second switch 12 and the second end of the 4th switch 14 are connected to ground, and the second end of third switch 13 is respectively with the 4th
The first end and testing capacitance C of switch 14dThe second pole plate connection；
Embodiment as one preferred, first switch 11, second switch 12, third switch 13, the 4th switch 14 are
Adg711 analog switch.
Embodiment as one preferred, first switch 11, second switch 12, third switch 13, the 4th switch 14 are
Relay.
It is connect with the control terminal of switching group module 1, for by current control instruction control switch group module 1 and currently
Control instruction it is corresponding close the switch, and control other switch disconnect control module 2；
Firstly the need of explanation, scheme provided by the utility model is mainly used to measure small value capacitor, testing capacitance
CdCapacitance be generally 0-1500pF.
Specifically, the utility model does not measure testing capacitance C directlydTwo pole plates between capacitance, by split
The connection relationship of each switch is designed in pass group module 1, makes the different switches in 2 control switch group module 1 of control module
When disconnecting and being closed, the available multiple measurement capacitances to testing capacitance Cd of management module 3.What control module 2 received
The number of control instruction be it is multiple, each control instruction different closed the switch/is disconnected for controlling, it is assumed that of control instruction
Number is four, is denoted as the first control instruction, the second control instruction, third control instruction and the 4th control instruction.First control refers to
Under order, control module 2 controls first switch 11 and the 4th switch 14 closure, and controls second switch 12 and third switch 13 and break
It opens；Under the second control instruction, control module 2 controls second switch 12 and third switch 13 is closed, and controls first switch 11
It is disconnected with the 4th switch 14；Under third control instruction, control module 2 controls first switch 11 and third switch 13 is closed, and
It controls second switch 12 and the 4th switch 14 disconnects；Under the 4th control instruction, control module 2 controls all switches and disconnects,
Wherein, control instruction can be tester's transmission, and herein for transmission sequence the utility model of each control instruction
Without limitation.It is emphasized that the claimed emphasis of the utility model is first switch 11 in switching group module 1,
The connection relationship of two switches 12, third switch 13 and the 4th switch 14 available is treated so that disconnecting and being closed different switches
The different measurement capacitance of capacitor is surveyed, is not how to control the disconnection and closure of each switch.
Specifically, first switch 11, second switch 12 in the utility model, third switch 13, the 4th switch 14
Think adg711 analog switch or relay or other switching devices, the utility model is it is not limited here.
It is connect with the first end of switching group module 1, for obtaining the testing capacitance C under current control instructiondSurvey
Capacitance is measured, and according to the measurement capacitance under all control instructions got, obtains testing capacitance CdActual capacitance value
Management module 3.
Specifically, referring to the connection relationship of each switch in switching group module 1 provided by the utility model, in the first control
System instruction under namely first switch 11 and the 4th switch 14 closure, second switch 12 and third switch 13 disconnection, management module 3
The measurement capacitance of acquisition includes testing capacitance CdActual capacitance value CX, internal parasitic capacitances value CinOver the ground with first pole plate
Capacitance C1, the second pole plate direct-to-ground capacitance is 0 by 14 short circuit of the 4th switch, the second pole plate direct-to-ground capacitance capacitance；In the second control
Under instruction namely second switch 12 and third switch 13 are closed, and first switch 11 and the disconnection of the 4th switch 14, management module 3 obtain
The measurement capacitance taken includes testing capacitance CdActual capacitance value CX, internal parasitic capacitances value CinWith the electricity of the second pole plate over the ground
Capacitance C2, the first pole plate direct-to-ground capacitance is 0 by 12 short circuit of second switch, the first pole plate direct-to-ground capacitance capacitance；Refer in third control
Under order namely first switch 11 and third switch 13 are closed, and the 4th switch 14 and second switch 12 disconnect, the acquisition of management module 3
Measurement capacitance include the capacitance C of the first pole plate over the ground1, the capacitance C of the second pole plate over the ground2And internal parasitic capacitances value
Cin, testing capacitance CdThe first pole plate and the second pole plate by first switch 11 and the short circuit of third switch 13, testing capacitance capacitance value
It is 0；Under the 4th control instruction, all switches are disconnected, and the measurement capacitance that management module 3 obtains is internal parasitic capacitances value
Cin, by weight of preset algorithm carries out, testing capacitance C can be obtaineddActual capacitance value.
Specifically, assuming that the measurement capacitance under above-mentioned 4 kinds of control instructions is denoted as C respectively01、C02、C03And C04, C01=
CX+Cin+C1, C02=CX+Cin+C2, C03=C2+Cin+C1, C04=Cin, therefore, it is not difficult to extrapolate, CX=(C01+C02-C03-C04)/
2, thus eliminating the need ground wire to the internal parasitic capacitances inside the stray capacitance and measuring system of two pole plates to electricity to be measured
Hold CdMeasurement result influence.
Certainly, the present embodiment proposed to testing capacitance CdCarry out four measurements and each control instruction control phase
That answers closes the switch/disconnects, and only has chosen a kind of scheme being most easy to implement, can be in addition to can using the above scheme
Using other schemes, includes such as other control instructions, control different switches and be opened or closed, to testing capacitance CdIt carries out multiple
Measurement etc. eliminates the stray capacitance of internal parasitic capacitances and two pole plates over the ground as long as being able to achieve, and the utility model is to this
Without limitation.
The utility model provides a kind of capacitance measurement system, including testing capacitance, switching group module, control module, pipe
Module is managed, switching group module includes first switch, second switch, third switch, the 4th switch, in which: the first of first switch
The first end switched with third is held to connect, first end of the common end as switching group module, the second end difference of first switch
It is connect with the first pole plate of the first end of second switch and testing capacitance, the second end of the second end of second switch and the 4th switch
It is connected to ground, the second end of third switch is connect with the second pole plate of the first end of the 4th switch and testing capacitance respectively；With
The control terminal connection of switching group module, for by current control instruction control switch group module with current control instruction pair
That answers closes the switch, and controls the control module that other switches disconnect；It is connect with the first end of switching group module, for obtaining
The measurement capacitance of testing capacitance under current control instruction, and according to the measurement capacitor under all control instructions got
Value, obtains the management module of the actual capacitance value of testing capacitance.
As it can be seen that in practical applications, using the embodiment of the utility model, passing through the company to each switch in switching group module
The relationship of connecing is designed, and make in control module control switch group module is different when switch on and off, and management module can be with
Multiple measurement capacitances of testing capacitance are got, and utilize preset algorithm, by inside that may be present in measurement capacitance
The stray capacitance that parasitic capacitance and ground wire generate two pole plates of testing capacitance all filters out, and then obtains testing capacitance
Actual capacitance value, the utility model does not need additional definite value capacitor, and is not limited by environmental factor, the reality of obtained testing capacitance
Border capacitance accuracy is higher.
Referring to figure 2., Fig. 2 is the structural schematic diagram of another capacitance measurement system provided by the utility model, the electricity
Hold measuring system on the basis of the above embodiments:
Embodiment as one preferred, management module 3 include:
For exporting the first square wave of predetermined level, to be testing capacitance CdFirst square wave unit 31 of charge/discharge；
First end connect with the output end of the first square wave unit 31, the first end connection of second end and switching group module 1, uses
In the second square wave unit 32 for exporting the second square wave, wherein the duty ratio and testing capacitance C of the second square wavedCharging time/put
The electric time corresponds；
Input terminal is connect, for the second square wave to be converted to turning for DC voltage value with the output end of the second square wave unit 32
Change unit 33；
It connect with the output end of converting unit 33, be converted to capacitor for obtaining DC voltage value, and by DC voltage value
The sampling unit 34 of value, wherein capacitance is the testing capacitance C under current control instructiondMeasurement capacitance.
Embodiment as one preferred, sampling unit 34 are microcontroller.
Specifically, it is default for generating the amplitude of a substantially stationary frequency (1.7KHz or so) by the first square wave unit 31
The square wave of level, predetermined level here can be set to 0-5V, and 0V is low level, and 5V is high level namely supply voltage,
Then pass through testing capacitance CdCharge/discharge characteristics, according to different testing capacitance CdIt is worth the difference of charge/discharge time, it is available
Second square wave of different duty, and then the second square wave of different duty is converted into DC voltage by converting unit 33
Value, is sampled by sampling unit 34, it is to be understood that includes the conversion pair of DC voltage value and capacitance in sampling unit 34
It should be related to, according to obtained DC voltage value and conversion corresponding relationship, so that it may obtain capacitor corresponding with DC voltage value
The size of value, the capacitance are the testing capacitance C under current control instructiondMeasurement capacitance.Correspondingly, different
Under control instruction, obtained measurement capacitance is also not all identical, wherein sampling unit 34 can be microcontroller.
Referring to figure 3., Fig. 3 is the structural schematic diagram of another capacitance measurement system provided by the utility model, the electricity
Hold measuring system on the basis of the above embodiments:
Embodiment as one preferred, the first square wave unit 31 include the first NAND gate equipped with Schmidt trigger
UD1, first capacitor C31, first resistor R1, second resistance R2And diode D1, in which:
First capacitor C31First end respectively with the first NAND gate UD1First input end, the first NAND gate UD1Second
Input terminal and first resistor R1First end connection, first capacitor C31Second end ground connection, the first NAND gate UD1Output end point
Not with first resistor R1Second end, diode D1Cathode, second resistance R2First end connection, common end is as first
The output end of square wave unit 31, diode D1Anode respectively with second resistance R2Second end and switching group module 1 first end
Connection.
Embodiment as one preferred, second resistance R2The resistance for being 1M Ω for resistance value.
Specifically, being illustrated first to the NAND gate for being equipped with Schmidt trigger, value that there are two Schmidt triggers, one
A is upper limit voltage threshold value Vh+With lower threshold voltage Vh-, when Schmidt trigger input terminal voltage from be lower than Vh+Electricity
Rising is pressed to, V is more than or equal toh+Afterwards, Schmidt trigger export high level, the voltage of input terminal decline from high to low when
It waits, and is less than or equal to Vh-Afterwards, Schmidt trigger export low level, therefore Schmidt trigger from high level go to low level or
Person goes to high level from low level, and input terminal can all be undergone from Vh+To Vh-Pressure difference, referring to shown in Fig. 4.
Specifically, the first square wave unit 31 includes the first NAND gate UD for having Schmitt trigger all the way1.It powers on just
Begin, the first NAND gate UD1Output end voltage VcFor high level, first capacitor C31Pass through first resistor R1Charging, when the first electricity
Hold C31Voltage the upper limit voltage threshold value V of Schmidt trigger is reached by chargingh+Afterwards, VcFor low level, first capacitor C31Again
Pass through first resistor R1Electric discharge, as first capacitor C31Tension discharge be put into the lower threshold voltage V of Schmidt triggerh-Afterwards,
VcBecome high level, then, VcThe voltage at place will appearance low and high level conversion in cycles, and the period converted is exactly the
One capacitor C31Charge and discharge are from Vh+To Vh-Between the sum of charge and discharge time.In this way in VcPlace has just obtained a substantially stationary frequency
The amplitude of rate is the square wave of 0-5v, and square wave frequency is 1.7KHz or so.
Wherein, first resistor R1It can choose the resistance that resistance value is 100K Ω, first capacitor C31Can choose capacitance is
The capacitor of 10nF, the second capacitor C32It can choose the capacitor that capacitance is 100nF, diode D1 can choose model 1N4148's
Diode.
Specifically, in VcBetween high period, testing capacitance CdPass through second resistance R2Charging is charged to its upper limit threshold electricity
Press Vh+Time be T1, in VcBetween low period, testing capacitance CdPass through diode D1Electric discharge, diode D1It can choose Xiao
Speed and conducting resistance all very littles is connected in special based diode, the second resistance R for being 1M Ω relative to resistance value2It can ignore not
Meter, therefore testing capacitance CdDischarge into its lower threshold voltage Vh-Time T2It can be ignored.So can only consider to
Survey capacitor CdThe case where charging time.
Embodiment as one preferred, the second square wave unit 32 include the second NAND gate equipped with Schmidt trigger
UD2；
Second NAND gate UD2First input end connect with the output end of the first square wave unit 31, the second NAND gate UD2's
Second input terminal is connect with the first end of switching group module 1.
Specifically, the second square wave unit 32 includes the second NAND gate UD equipped with Schmidt trigger2.Second NAND gate UD2
The second input termination switch group module 1, it is to be understood that connect by switching group module 1 is testing capacitance CdA certain pole
The capacitor of plate over the ground, it can be understood as the second NAND gate UD2The second input terminal on V4Point is exactly the testing capacitance C connectdOne
A electrode, and testing capacitance CdAnother electrode be ground connection.
According to above-mentioned principle, V is only analyzedcFor the logical relation between the high period of a square-wave cycle, the second NAND gate
UD2Output voltage V5With the first NAND gate UD1Output voltage VcIt compares, the second NAND gate UD2Output voltage will receive to
Survey capacitor CdSize influence, because only that working as V4The voltage at place is greater than UD2The Schmidt's touching connected inside second input terminal
Send out the upper limit threshold voltage V of deviceh+Afterwards,
UD2Two input pins of NAND gate are just all high level, at this time V5Output is just low level, V5Relative to VcIt is high
Level duration ratio VcThe low level duration has grown T1Time, testing capacitance CdPass through second resistance R2Charging, Ke Yili
Solution, V4The voltage at place reaches the second NAND gate UD2Upper limit threshold voltage Vh+Time T1With testing capacitance CdSize at
Direct ratio, i.e. testing capacitance CdBigger T1It is bigger, therefore, testing capacitance CdSize will affect the second NAND gate UD2The second of output
The duty ratio of square wave, specific waveform diagram is referring to Figure 5.Embodiment as one preferred, converting unit 33 are low pass filtered
Wave device.
Embodiment as one preferred, low-pass filter include 3rd resistor R3With the second capacitor C32, in which:
3rd resistor R3Input terminal of the first end as converting unit 33,3rd resistor R3Second end and the second capacitor
C32First end connection, output end of the common end as converting unit 33, the second capacitor C32Second end be connected to ground.
Specifically, converting unit 33 can be for one by 3rd resistor R3With the second capacitor C32Low-pass filter is formed, it will
Second square wave of the second square wave unit 32 output passes through 3rd resistor R3With the second capacitor C32Low-pass filtering is DC voltage value, with
Just sampling unit 34 is sampled.
In conclusion the utility model is broken by what difference in the four adg711 analog switches of control of control module 2 switched
Open and close are closed, and do not measure the capacitance between the two-plate of measured capacitance directly, but by four measurements, it, can using algorithm
Ground wire is to testing capacitance C in measuring system existing for energydStray capacitance and free surrounding space to testing capacitance CdStray capacitance and
Internal parasitic capacitances inside measuring system all filter out, accurately to measure testing capacitance CdSize.
Each embodiment in this specification is described in a progressive manner, the highlights of each of the examples are with other
The difference of embodiment, the same or similar parts in each embodiment may refer to each other.For device disclosed in embodiment
For, since it is corresponded to the methods disclosed in the examples, so being described relatively simple, related place is said referring to method part
It is bright.
The foregoing description of the disclosed embodiments can be realized professional and technical personnel in the field or using originally practical new
Type.Various modifications to these embodiments will be readily apparent to those skilled in the art, and determine herein
The General Principle of justice can be realized in other embodiments without departing from the spirit or scope of the present utility model.Cause
This, the present invention will not be limited to the embodiments shown herein, and is to fit to and principles disclosed herein
The widest scope consistent with features of novelty.
Claims (10)
1. a kind of capacitance measurement system, which is characterized in that including testing capacitance, switching group module, control module, management module,
The switching group module includes first switch, second switch, third switch, the 4th switch, in which:
The first end of the first switch is connected with the first end that the third switchs, and common end is as the switching group module
First end, the second end of the first switch the first pole with the first end of the second switch and the testing capacitance respectively
The second end of plate connection, the second end of the second switch and the 4th switch is connected to ground, and the of third switch
Two ends are connect with the second pole plate of the first end of the 4th switch and the testing capacitance respectively；
Connect with the control terminal of the switching group module, for by current control instruction control in the switching group module with work as
Preceding control instruction is corresponding to be closed the switch, and controls the control module that other switches disconnect；
It is connect with the first end of the switching group module, the survey for obtaining the testing capacitance under current control instruction
Capacitance is measured, and according to the measurement capacitance under all control instructions got, obtains the actual capacitance of the testing capacitance
The management module of value.
2. capacitance measurement system according to claim 1, which is characterized in that the management module includes:
For exporting the first square wave of predetermined level, so as to the first square wave unit for the testing capacitance charge/discharge；
First end is connect with the output end of the first square wave unit, second end is connect with the first end of the switching group module,
For exporting the second square wave unit of the second square wave, wherein the duty ratio of second square wave and the charging of the testing capacitance
Time/discharge time corresponds；
Input terminal is connect, for second square wave to be converted to DC voltage value with the output end of the second square wave unit
Converting unit；
It connect with the output end of the converting unit, converted for obtaining the DC voltage value, and by the DC voltage value
For the sampling unit of capacitance, wherein the capacitance is the measurement electricity of the testing capacitance under current control instruction
Capacitance.
3. capacitance measurement system according to claim 2, which is characterized in that the first square wave unit includes close equipped with applying
First NAND gate of special trigger, first capacitor, first resistor, second resistance and diode, in which:
The first end of the first capacitor respectively with the first input end of first NAND gate, first NAND gate second
The first end of input terminal and the first resistor connection, the first capacitor second end ground connection, first NAND gate it is defeated
Outlet is connect with the first end of the second end of the first resistor, the cathode of the diode, the second resistance respectively, public
Output end of the end as the first square wave unit altogether, the anode of the diode respectively with the second end of the second resistance and
The first end of the switching group module connects.
4. capacitance measurement system according to claim 3, which is characterized in that the second square wave unit includes close equipped with applying
Second NAND gate of special trigger；
The first input end of second NAND gate is connect with the output end of the first square wave unit, second NAND gate
Second input terminal is connect with the first end of the switching group module.
5. capacitance measurement system according to claim 4, which is characterized in that the converting unit is low-pass filter.
6. capacitance measurement system according to claim 5, which is characterized in that the low-pass filter include 3rd resistor and
Second capacitor, in which:
Input terminal of the first end of the 3rd resistor as the converting unit, the second end of the 3rd resistor and described the
The first end of two capacitors connects, output end of the common end as the converting unit, the second end and ground of second capacitor
Connection.
7. capacitance measurement system according to claim 6, which is characterized in that the sampling unit is microcontroller.
8. capacitance measurement system according to claim 7, which is characterized in that the first switch, the second switch, institute
State third switch, the 4th switch is adg711 analog switch.
9. capacitance measurement system according to claim 7, which is characterized in that the first switch, the second switch, institute
State third switch, the 4th switch is relay.
10. capacitance measurement system according to claim 7, which is characterized in that the second resistance is that resistance value is 1M Ω
Resistance.
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| CN201821214127.3U CN208459485U (en) | 2018-07-27 | 2018-07-27 | A kind of capacitance measurement system |
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| CN (1) | CN208459485U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108614161A (en) * | 2018-07-27 | 2018-10-02 | 青岛澳科仪器有限责任公司 | A kind of capacitance measurement system |
| CN109900983A (en) * | 2019-02-26 | 2019-06-18 | 北京航空航天大学 | A kind of measuring device of high frequency transformer parasitic parameter |
| CN113160662A (en) * | 2021-04-19 | 2021-07-23 | 杭州优必学科技有限公司 | Capacitor-based programming building block control method and system |
-
2018
- 2018-07-27 CN CN201821214127.3U patent/CN208459485U/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108614161A (en) * | 2018-07-27 | 2018-10-02 | 青岛澳科仪器有限责任公司 | A kind of capacitance measurement system |
| CN108614161B (en) * | 2018-07-27 | 2024-04-16 | 青岛澳科仪器有限责任公司 | Capacitance measuring system |
| CN109900983A (en) * | 2019-02-26 | 2019-06-18 | 北京航空航天大学 | A kind of measuring device of high frequency transformer parasitic parameter |
| CN109900983B (en) * | 2019-02-26 | 2020-07-07 | 北京航空航天大学 | Measuring device for parasitic parameters of high-frequency transformer |
| CN113160662A (en) * | 2021-04-19 | 2021-07-23 | 杭州优必学科技有限公司 | Capacitor-based programming building block control method and system |
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