CN104142430A - RLC measuring instrument and measuring method - Google Patents
RLC measuring instrument and measuring method Download PDFInfo
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Abstract
The invention relates to an RLC measuring instrument. The CPLD technology is adopted for replacing a digital circuit to generate sine detection signals, chip resources on a CPLD development board are rich, PLLs are contained in the CPLD development board, and the frequency can be multiplied and divided conveniently. The RLC measuring instrument comprises a storage unit, a ROM table macroblock can be directly called, an SOPC can be used as a kernel, high-frequency test signals can be obtained conveniently, and the waveform quality of the sine detection signals can be improved. The invention further relates to a measuring method based on the RLC measuring instrument. The direct digital frequency synthesis technique is adopted, the frequency and the phase of the output sine detection signals can be accurately controlled, and meanwhile, the measuring instrument has the advantages that frequency switching time is short, the frequency resolution is high, the phase is changed continuously, phase noise and drifting are low, and integration and adjustment are easy.
Description
Technical field
The present invention relates to a kind of RLC measuring instrument and measuring method.
Background technology
RLC component parameters surveying instrument is for measuring the surveying instrument of lumped parameter resistance R, inductance L, inductance M, capacitor C and quality factor q, is a kind of material industry, medical industry, the electronic information industry measurement of various correlation parameters and multipurpose instrument of data analysis of being widely used in.
Resistance, inductance, electric capacity, kind, still quantitatively say it is all to use electronic devices and components very frequently, along with the development of the aspects such as electronic material, technique and use, the characteristic of the components and parts such as resistance, inductance, electric capacity and quality factor its value under different frequency electronic circuit thereof is had higher requirement.The inductance value of most of inductor can vary widely when using different survey frequencies and test signal level, and aluminium electrolutic capacitor is also along with its value of change of survey frequency also variation sharply can occur.On market, the nominal value of common resistance R, inductance L, capacitor C is all the value of measuring under 1kHz frequency test signal and the effect of 1V test signal level, does not have versatility.The survey frequency of product in the market, mostly 30HZ～300KHZ (adopting single-chip microcomputer design), can not meet the demand of device measuring frequency range.
Summary of the invention
For above-mentioned technical matters, technical matters to be solved by this invention is to provide a kind of based on CPLD technology, meets the RLC measuring instrument of device measuring frequency range demand.
Corresponding therewith, for above-mentioned technical matters, technical matters to be solved by this invention is to provide a kind of RLC measuring instrument based on the present invention's design, meets the measuring method of device measuring frequency range demand.
The present invention is in order to solve the problems of the technologies described above by the following technical solutions: the present invention has designed a kind of RLC measuring instrument, comprises preposition testing circuit module, difference processing circuit module, detecting circuit module, integration module, signal acquisition process control single chip computer, two-port RAM, input/output control module, load module, output module, low pass filter blocks and D/A converter, also comprise CPLD control panel, wherein, the output terminal of preposition testing circuit module is connected with the input end of difference processing circuit module, the output terminal of difference processing circuit module is connected with one of them input end of detecting circuit module, the output terminal of detecting circuit module is connected with the input end of integration module, the output terminal of integration module is connected with the input end of signal acquisition process control single chip computer, the output terminal of signal acquisition process control single chip computer is connected with the input end of CPLD control panel, signal acquisition process control single chip computer carries out interactive communication with two-port RAM simultaneously, two output terminals of CPLD control panel respectively with detecting circuit module, D/A converter is connected, the output terminal of D/A converter is connected with the input end of low pass filter blocks, simultaneously respectively with detecting circuit module, D/A converter is connected, two-port RAM and input/output control module carry out interactive communication, the input end of input/output control module, output terminal respectively with load module, output module is connected.
As a preferred technical solution of the present invention: described integration module comprises interconnective integrating A/D converter sum counter, wherein, the output terminal of described detecting circuit module is connected with the input end of integrating A/D converter, and the output terminal of integrating A/D converter is connected with the input end of described signal acquisition process control single chip computer.
As a preferred technical solution of the present invention: described CPLD control panel is CPLD development board.
As a preferred technical solution of the present invention: described input/output control module is Keyboard and display control single-chip microcomputer, and described input media is finger-impu system, and described output unit is liquid crystal indicator.
A kind of RLC measuring instrument of the present invention adopts above technical scheme compared with prior art, there is following technique effect: the RLC measuring instrument of the present invention's design, adopt CPLD technology to substitute by digital circuit and produce sinusoidal detection signal, and on CPLD development board, resources of chip is abundant, include PLL phaselocked loop, conveniently realize frequency multiplication and frequency division, and comprise storage unit, can directly call ROM table macroblock, and can apply SOPC and realize kernel, be convenient to realize high-frequency test signal, can improve the waveform quality of sinusoidal detection signal, effectively widen the measurement range of sinusoidal detection signal, meet device measuring frequency range demand, and be convenient to upgrading and safeguard.
Corresponding therewith, the present invention is in order to solve the problems of the technologies described above by the following technical solutions: the present invention has designed a kind of measuring method that designs RLC measuring instrument based on the present invention, comprises the steps:
Described in step 001., load module sends control command through input/output control module, two-port RAM, signal acquisition process control single chip computer to described CPLD control panel, described CPLD control panel adopts direct digital frequency synthesis technology, produces and controls sinusoidal detection signal be delivered to tested electronic devices and components through D/A converter, low pass filter blocks according to the control command receiving;
Described in step 002., preposition testing circuit module detects for tested electronic devices and components, obtains the detection signal of tested electronic devices and components, and is delivered to described difference processing circuit module and processes;
After described in step 003., difference processing circuit module is processed for detection signal, be sent to detecting circuit module, described load module sends phase demodulation control command through input/output control module, two-port RAM, signal acquisition process control single chip computer to described CPLD control panel, described CPLD control panel adopts direct digital frequency synthesis technology, according to the phase demodulation control command receiving, control detecting circuit module pin and carry out to the received signal two phase demodulations, and phase discrimination signal is sent to described integrating A/D converter;
Described in step 004., integrating A/D converter receives phase discrimination signal, and according to the counter being attached thereto, for phase discrimination signal, carries out integration, and converts its mean value to corresponding digital quantity signal, is sent to described signal acquisition process control single chip computer;
Described in step 005., signal acquisition process control single chip computer receives digital quantity signal, through two-port RAM, input/output control module, by output module, exports.
As a preferred technical solution of the present invention: in described step 001, described CPLD control panel adopts direct digital frequency synthesis technology, produces and controls 20Hz～1MHz sinusoidal detection signal be delivered to tested electronic devices and components through D/A converter, low pass filter blocks according to the control command receiving.
As a preferred technical solution of the present invention: in described step 003, described CPLD control panel is controlled detecting circuit module pin and is carried out to the received signal, in two phase demodulation processes, adopting three road square waves to carry out phase demodulation to the voltage differential signal of tested electron device and standard resistor at two terminals.
A kind of measuring method that designs RLC measuring instrument based on the present invention of the present invention adopts above technical scheme compared with prior art, there is following technique effect: the present invention's design designs the measuring method of RLC measuring instrument based on the present invention, based on CPLD technology, adopt direct digital frequency synthesis technology, can accurately control frequency and the phase place of output sinusoidal detection signal, simultaneously direct digital frequency synthesis technology have that frequency switching time is short, frequency resolution is high, phase place changes continuously, there is low phase noise and low drift, be easy to integrated, be easy to the advantages such as adjustment; And in the measuring method of the present invention's design, adopted two phase demodulations, the impact that the synthetic waveform after phase demodulation is subject to DC voltage ripple in integral process has reduced, and makes the precision of measurement result improve one, and this improves the competitiveness of product in market greatly.
Accompanying drawing explanation
Fig. 1 is the RLC measuring instrument that designs of the present invention and the structural representation of measuring method;
Fig. 2 is that the present invention designs preposition testing circuit modular circuit schematic diagram in RLC measuring instrument;
Fig. 3 is that the present invention designs difference processing circuit module circuit diagram in RLC measuring instrument;
Fig. 4 is that the present invention designs detecting circuit module diagram in RLC measuring instrument;
Fig. 5 is that the present invention designs integration module schematic diagram in RLC measuring instrument;
Fig. 6 is that the present invention designs RLC measuring instrument Counter schematic diagram;
Fig. 7 is that the present invention designs Keyboard and display control single-chip microcomputer schematic diagram in RLC measuring instrument.
Embodiment
Below in conjunction with Figure of description, the specific embodiment of the present invention is described in further detail.
As shown in Figure 1, the present invention has designed a kind of RLC measuring instrument, comprises preposition testing circuit module, difference processing circuit module, detecting circuit module, integration module, signal acquisition process control single chip computer, two-port RAM, input/output control module, load module, output module, low pass filter blocks and D/A converter, also comprise CPLD control panel, wherein, the output terminal of preposition testing circuit module is connected with the input end of difference processing circuit module, the output terminal of difference processing circuit module is connected with one of them input end of detecting circuit module, the output terminal of detecting circuit module is connected with the input end of integration module, the output terminal of integration module is connected with the input end of signal acquisition process control single chip computer, the output terminal of signal acquisition process control single chip computer is connected with the input end of CPLD control panel, signal acquisition process control single chip computer carries out interactive communication with two-port RAM simultaneously, two output terminals of CPLD control panel respectively with detecting circuit module, D/A converter is connected, the output terminal of D/A converter is connected with the input end of low pass filter blocks, simultaneously respectively with detecting circuit module, D/A converter is connected, two-port RAM and input/output control module carry out interactive communication, the input end of input/output control module, output terminal respectively with load module, output module is connected.RLC measuring instrument based on above technical scheme, adopt CPLD technology to substitute by digital circuit and produce sinusoidal detection signal, and on CPLD development board, resources of chip enriches, includes PLL phaselocked loop, conveniently realize frequency multiplication and frequency division, and comprise storage unit, can directly call ROM table macroblock and can apply SOPC and realize kernel, be convenient to realize high-frequency test signal, can improve the waveform quality of sinusoidal detection signal, effectively widen the measurement range of sinusoidal detection signal, meet device measuring frequency range demand, and be convenient to upgrading and safeguard.
On basis based on above design technology project: described integration module comprises interconnective integrating A/D converter sum counter, wherein, the output terminal of described detecting circuit module is connected with the input end of integrating A/D converter, and the output terminal of integrating A/D converter is connected with the input end of described signal acquisition process control single chip computer; Described CPLD control panel is CPLD development board; Described input/output control module is Keyboard and display control single-chip microcomputer, and described input media is finger-impu system, and described output unit is liquid crystal indicator.
Corresponding with the RLC measurement of above-mentioned design, the present invention has also designed the measuring method based on this RLC measuring instrument, comprises the steps:
Described in step 001., load module sends control command through input/output control module, two-port RAM, signal acquisition process control single chip computer to described CPLD control panel, described CPLD control panel adopts direct digital frequency synthesis technology, produces and controls 20Hz～1MHz sinusoidal detection signal be delivered to tested electronic devices and components through D/A converter, low pass filter blocks according to the control command receiving;
Described in step 002., preposition testing circuit module detects for tested electronic devices and components, obtains the detection signal of tested electronic devices and components, and is delivered to described difference processing circuit module and processes;
After described in step 003., difference processing circuit module is processed for detection signal, be sent to detecting circuit module, described load module is through input/output control module, two-port RAM, signal acquisition process control single chip computer sends phase demodulation control command to described CPLD control panel, described CPLD control panel adopts direct digital frequency synthesis technology, according to the phase demodulation control command receiving, control detecting circuit module pin and carry out to the received signal two phase demodulations, and phase discrimination signal is sent to described integrating A/D converter, wherein, in two phase demodulation processes, adopt three road square waves to carry out phase demodulation to the voltage differential signal of tested electron device and standard resistor at two terminals,
Described in step 004., integrating A/D converter receives phase discrimination signal, and according to the counter being attached thereto, for phase discrimination signal, carries out integration, and converts its mean value to corresponding digital quantity signal, is sent to described signal acquisition process control single chip computer;
Described in step 005., signal acquisition process control single chip computer receives digital quantity signal, through two-port RAM, input/output control module, by output module, exports.
The present invention designs in RLC measuring instrument and measuring method, for CPLD development board, under QUARTUSII development environment, application hardware descriptive language coding, substitute by digital circuit and produce sinusoidal detection signal, and be convenient to upgrading and safeguard, if want to improve the frequency of sinusoidal detection signal, only need to revise Verilog or VHDL program, prerequisite is that the resource of CPLD or FPGA is more than enough, and direct digital frequency synthesis technology (DDS) employing is with software programming, to realize the function of hardware, beginner can learn and grasp this technology in a short period of time, develop practical outstanding product.And the frequency that adopts digital circuit to revise sine wave signal is very very difficult, require developer to have very deep circuit base, wherein, described CPLD control panel is CPLD development board, integrated SDRAM and FLASH on development board, a lot of free IP kernels in QUARTUSII development environment, have been carried, can in SOPC, design CPU core, design software in NIOSII, the Top-layer Design Method of engineering downloads in the EPCS chip of development board, and the software programming designing in NIOSII is in FLASH chip, the present invention is based on such method for designing, through exploitation and debugging, design the sinusoidal wave test signal of 20Hz～1MHz, widened the measurement range of sinusoidal detection signal.
Moreover, in two phase demodulation processes in step 003, adopt three road square waves to carry out phase demodulation to the voltage differential signal of tested electron device and standard resistor at two terminals, than single phase demodulation, two phase demodulations have adopted two-way square-wave signal more, between three road square-wave signals with 0 °, 45 °, 90 °, 135 °, 180 °, 225 °, 270 °, the phase relation of 315 ° exists, through derivation of equation proof, adopt two phase demodulations equally can realize separated to the voltage differential signal real part of measured device and standard resistor at two terminals and imaginary part, key is to have adopted after two phase demodulations, the impact that synthetic waveform after phase demodulation is subject to DC voltage ripple in integral process has reduced, and show through test, the precision of measurement result has improved one, this improves the competitiveness of product in market greatly.
In the present invention, preposition testing circuit modular circuit schematic diagram, controls three or eight code translators 74138 by P1.5, P1.6, the P1.7 pin of signal acquisition process control single chip computer and carrys out choice criteria resistance as shown in Figure 2.Tested electronic devices and components are placed between HS, LS, HS, HD are connected, LS, LD are connected, the sinusoidal detection signal that CPLD control panel produces is added in HD end, the V/I port controlling that the control end of 4052 chips is exported to SN74ALS574A chip by SN74LS245A chip by the P0 mouth of signal acquisition process control single chip computer; By V/I port, select tested electronic devices and components or the output of the both end voltage of measuring resistance is the output of SIGNAL1, SIGNAL2; And 74138 A, B, C end is controlled by P1.5 (RANG1), P1.6 (RANG2), P1.7 (RANG3) output of signal acquisition process control single chip computer; When the some pins when 74138 are low level, the relay connecting is therewith connected, and has just selected measuring resistance, by the various combination of these three pin, selects different measuring resistances, and tested electronic devices and components are placed on test fixture.
The major function of difference processing circuit module is the voltage difference that obtains tested electronic devices and components and standard resistor at two terminals, difference processing circuit module circuit diagram as shown in Figure 3, SIGNAL1, SIGNAL2 signal is the output signal of preposition testing circuit module, be respectively the voltage at measuring resistance and tested electronic devices and components two ends, these two signals pass through respectively voltage follower, because these two voltage signals itself are not very little, so just do not need to amplify by subtraction circuit, what the positive and negative two ends of subtraction circuit amplifier all adopted here is the resistance of 5K, DB7～DB0 of AD7524 is controlled by the data bus of signal acquisition process control single chip computer, be used for amplifying the magnitude of voltage at measuring resistance and tested electronic devices and components two ends, be convenient to measurement below.Wherein, amplifier U15 and U16 form a subtraction circuit, and establishing SIGNAL1 is V
1, SIGNAL2 is V
2, the output terminal of U16 is V
out2 terminal voltages be V
0, according to the voltage of short acquisition 3 ends of the void of amplifier, be also V
0, U15 is two voltage followers, from modal equation:
According to R36=5k Ω, R38=5k Ω, R37=5k Ω, R39=5k Ω, is released by formula (1) and formula (2):
V
out＝V
2-V
1 (3)
Realized the measurement of tested electronic devices and components and standard resistor at two terminals voltage.
If AD7524 dwindles 4 times in low-pass filter, at difference processing circuit module, just amplify 2 times.
D23～D26 is used for protecting positive and negative 12 volts of power supplys, and U19 is voltage follower, and U20 is that 4052 electronic switches are used for selecting output, if measure impedance Z
xmould value be less than 30, range resistance is just selected the resistance of imaginary quantity journey 10 Ω so, RANG4 is with regard to gating X0, otherwise RANG4 is with regard to gating X1.Signal voltage before input 4052, the bleeder circuit forming through R44 and R45, it is original 1/3rd that signal voltage becomes, after 4052, by R46 and R47, signal voltage becomes original three times, returns to again original amplitude.By INPUT, hold to deliver to and in detecting circuit, carry out phase demodulation.
The explanation of imaginary quantity journey 10 Ω resistance: imaginary quantity journey 10 Ω resistance are non-existent in fact, when measuring impedance Z
xmould value be less than at 30 o'clock, that measuring resistance is also selected is 30 Ω, and now in order to keep the amplitude of INPUT signal, RANG4, with regard to gating X0, then passes through by R46 and R47, and signal voltage amplifies three times, be equivalent to signal voltage and do not amplify, and measuring resistance employing is 10 Ω resistance.The concept of Here it is imaginary quantity journey 10 Ω resistance.
In the present invention, the effect of detecting circuit module be by
with different fixed phase phase demodulations, complete the separated of measured device and standard resistor at two terminals voltage real part and imaginary part, detecting circuit module diagram as shown in Figure 4, the input INPUT of detecting circuit module is the output of difference processing circuit, PHAB, PHB, PHA is input as wave0, wave21, wave41, be used for controlling multiway analog switch device and turn-off selection input waveform, wave0 occurs 0 ° under the effect of phase control words, 90 °, 180 °, 270 ° of variations, and wave21, the phase relation of wave41 and wave0 is fixed, then at multiway analog switch output, three kinds of waveform stacks, PHAB, PHB, PHA is by the pin 30 (PHAB) of CPLD, 31 (PHB), 29P (PHA) output is controlled.Wherein, U22 amplifier is inverting amplifier, in U23 device, used the resistance of 14.1k Ω, in U24 device, used the resistance of 10k Ω, and the feedback resistance of amplifier U25 is also 14.1k Ω, mainly because the phase differential that PHAB phase demodulation square wave in U23 contains 90 degree, and the phase differential that contains 45 degree in PHA in U24 and PHB phase demodulation square wave, so enlargement factor is
doubly, conveniently in software, data are processed.
In the present invention, integration module has adopted the integrating A/D converter of a kind of being referred to as " charge balance ".Integration module schematic diagram as shown in Figure 5, mainly by these several parts, formed: compensator-amplifier unit, switching device, three grades of comparers and digital logic device, they make to input to the action synchronised of the thick counting of integrator and smart counter switch and thick counting, smart counter, timer conter has three passages, pass through system bus, the integral multiple that be test frequency the integral time of controlling A/D, can eliminate like this alternating component containing in phase demodulation output completely, below by integrated waveform, describe A/D transfer process.Integrated waveform is from 0V level, when A is high level, integrator is oblique+5V electrical level rising, when reach+5V level, it is high level that an action that is referred to as " HC " makes B, make thick reference signal add integrator simultaneously, now two kinds of signals add on integrator simultaneously, integration output declines to zero level, when being down to 0.45V, to make B be low level in " LC " action, now A is still in high level state, integrator output is risen to+5V again, after arrival+5V, B is again high level, output declines to 0.45V again, so circulate until integration period 20ms finishes, then allow the C be high level, allow electric capacity continue electric discharge, when the moment that electric capacity is discharged, " ZC " action, by GAL, make D become high level, when signal acquisition process control single chip computer receives D signal, A/D transfer process has just been described one time, initialization A, B, C, D signal.Then continue to have judged whether 8 times, if be less than, just proceed A/D conversion for 8 times, until 8 times.Finally, this count value of 8 times process mathematical operation, the formula in application principle just can have been calculated the characteristic of measured device.Adopt the object of this switching technique to be that between integrator output remain at+5V～+ 0.45V, the integration of the long period that this just makes can not surpass the range of linearity, for the setting of integral time provides well-to-do scope.In addition, owing to having added with reference to discharge signal in integration period, also just shortened total A/D switching time, this " charge balance " A/D transfer process that is this.Thick, essence with reference between have following relation to exist, when B is high level, the counter 1 that corresponding thick counting is 82C54 is just in count tracking state.After 20ms, allow the C be high level, the counter 2 that smart counting is 82C54 is in count tracking state, these two count values have following relation: a thick counting equals 512 smart count values, 82C54 is 4 times of count frequency (500kHz) to C to the count frequency of B (2MHz), integrating resistor is 128 times of (R60=10k Ω simultaneously, R61=1.28M Ω), like this, can obtain the resolution of this instrument A/D converter, slightly, smart counter is 16, has above-mentioned 512 times of relations to exist between the two, total meter digital should be 16+9=25 position.Here by adjusting the width of UNK signal, just can realize the selection of test speed: quick, middling speed, three kinds of speed at a slow speed.Middling speed UNK is 20ms, and UNK is 10ms fast, and UNK is 40ms at a slow speed.
In the RLC measuring instrument of the present invention's design, described integration module comprises interconnective integrating A/D converter sum counter, wherein, counter adopts 82C54 counter circuit, and the effect of counter is the magnitude of voltage of tested electronic devices and components and measuring resistance is converted into the process of counting by integration.In order to meet the sequential of integrating A/D converter, counter works is set in mode 2, the initial value of counter is 0xffff, it is the requirement that 0xffff can meet counting in 20ms that initial value is set, as the GATE1 of counter,, the B of GATE2, C signal while being low level, CLK1, CLK2 under the effect of 500kHz, 2MHz frequency, start to subtract 1 to the initial value of counter respectively, until an integral process completes, counter subtrahend process also stops; As shown in Figure 6, the CS chip selection signal of 82C54 is exported by P2.0, the P2.1 of signal acquisition process control single chip computer, the Y1 of P2.2 port controlling SN74LS138, when master routine enters integration subroutine, signal acquisition process control single chip computer sends ADST signal, allow the counter 0 of 82C54 work, then under the effect of F, count, finally the square wave (under middling speed mode) at a 20ms of OUT1 pin generation is the UNK signal in A/D conversion integration sequence.GATE1 and GATE2 are signal B and the C that GAL16V8 sends, and the count frequency signal that the pin that CLK0, CLK1, CLK2 are CPLD sends.Complete one-shot measurement, counter need to be counted 8 times, and measuring resistance and tested electronic devices and components are counted respectively 4 times; If first tested electronic devices and components are carried out to integration, under the effect of phase control words, there are 0 °, 90 °, 180 °, 270 ° variations in phase discrimination signal wave0, and the phase relation of wave21, wave41 and wave0 is fixed, under the two phase discrimination signals that change in four kinds of phase places, count value is made as respectively X1, X2, X3, X4, through formula N1=(X3-X1)/2, N2=(X4-X2)/2, can obtain the value of N1 and N2, equally measuring resistance is carried out to integration, it is the same that the variation of phase discrimination signal and tested electronic devices and components carry out integral process, also can obtain Y1, Y2, Y3, Y4.Through formula N3=(Y3-Y1)/2, N4=(Y4-Y2)/2, can obtain the value of N3 and N4, then according to the formula in 2.1 joints, can calculate needed parameter value, but be noted that the value now calculating need to just imitate in software, then by liquid crystal indicator display measurement value.
Eight of DB0～DB7 in AD7524 in the data bus control difference processing circuit module of the signal acquisition process control single chip computer in the present invention's design, control CPLD development board output sinusoidal detection signal through the waveform voltage of tested electronic devices and components and measuring resistance; The data bus of signal acquisition process control single chip computer produces in low pass filter blocks 4052 control signal, 4052 control signal in preposition testing circuit module, the phase control words signal of CPLD by 74LS245,74ALS574; Control signal and cue between signal acquisition process control single chip computer and counter 82C54, GAL16V8, and the data of be responsible for processing in 82C54 revise data in signal acquisition process control single chip computer, send in Keyboard and display control single-chip microcomputer and show.
The present invention designs in RLC measuring instrument, described input/output control module is Keyboard and display control single-chip microcomputer, Keyboard and display control single-chip microcomputer is accepted the input of finger-impu system, be used for producing frequency control word and various control signal, by two-port RAM, send in signal acquisition process control single chip computer and process; And Keyboard and display control Single-chip Controlling liquid crystal indicator, the data that the input of display keyboard input media and signal acquisition process control single chip computer send over.Keyboard and display control single-chip microcomputer schematic diagram as shown in Figure 7, the DISR of Keyboard and display control single-chip microcomputer is the serial ports input signal of finger-impu system, input signal be take DISK as incoming frequency, KEY0～KEY4 is the output signal of finger-impu system, Keyboard and display control single-chip microcomputer reads in this signal, and in conjunction with the serial signal of DISR input, just can judge the position of button, thereby the word program that enters this button is processed accordingly.X1-M, X2-M are crystal oscillator connector, and REST is reset signal.
By reference to the accompanying drawings embodiments of the present invention are explained in detail above, but the present invention is not limited to above-mentioned embodiment, in the ken possessing those of ordinary skills, can also under the prerequisite that does not depart from aim of the present invention, makes a variety of changes.
Claims (7)
1. a RLC measuring instrument, comprises preposition testing circuit module, difference processing circuit module, detecting circuit module, integration module, signal acquisition process control single chip computer, two-port RAM, input/output control module, load module, output module, low pass filter blocks and D/A converter, it is characterized in that: also comprise CPLD control panel, wherein, the output terminal of preposition testing circuit module is connected with the input end of difference processing circuit module, the output terminal of difference processing circuit module is connected with one of them input end of detecting circuit module, the output terminal of detecting circuit module is connected with the input end of integration module, the output terminal of integration module is connected with the input end of signal acquisition process control single chip computer, the output terminal of signal acquisition process control single chip computer is connected with the input end of CPLD control panel, signal acquisition process control single chip computer carries out interactive communication with two-port RAM simultaneously, two output terminals of CPLD control panel respectively with detecting circuit module, D/A converter is connected, the output terminal of D/A converter is connected with the input end of low pass filter blocks, simultaneously respectively with detecting circuit module, D/A converter is connected, two-port RAM and input/output control module carry out interactive communication, the input end of input/output control module, output terminal respectively with load module, output module is connected.
2. a kind of RLC measuring instrument according to claim 1, it is characterized in that: described integration module comprises interconnective integrating A/D converter sum counter, wherein, the output terminal of described detecting circuit module is connected with the input end of integrating A/D converter, and the output terminal of integrating A/D converter is connected with the input end of described signal acquisition process control single chip computer.
3. a kind of RLC measuring instrument according to claim 1, is characterized in that: described CPLD control panel is CPLD development board.
4. according to a kind of RLC measuring instrument described in any one in claims 1 to 3, it is characterized in that: described input/output control module is Keyboard and display control single-chip microcomputer, described input media is finger-impu system, and described output unit is liquid crystal indicator.
5. the measuring method based on a kind of RLC measuring instrument described in any one in claim 2 to 4, is characterized in that, comprises the steps:
Described in step 001., load module sends control command through input/output control module, two-port RAM, signal acquisition process control single chip computer to described CPLD control panel, described CPLD control panel adopts direct digital frequency synthesis technology, produces and controls sinusoidal detection signal be delivered to tested electronic devices and components through D/A converter, low pass filter blocks according to the control command receiving;
Described in step 002., preposition testing circuit module detects for tested electronic devices and components, obtains the detection signal of tested electronic devices and components, and is delivered to described difference processing circuit module and processes;
After described in step 003., difference processing circuit module is processed for detection signal, be sent to detecting circuit module, described load module sends phase demodulation control command through input/output control module, two-port RAM, signal acquisition process control single chip computer to described CPLD control panel, described CPLD control panel adopts direct digital frequency synthesis technology, according to the phase demodulation control command receiving, control detecting circuit module pin and carry out to the received signal two phase demodulations, and phase discrimination signal is sent to described integrating A/D converter;
Described in step 004., integrating A/D converter receives phase discrimination signal, and according to the counter being attached thereto, for phase discrimination signal, carries out integration, and converts its mean value to corresponding digital quantity signal, is sent to described signal acquisition process control single chip computer;
Described in step 005., signal acquisition process control single chip computer receives digital quantity signal, through two-port RAM, input/output control module, by output module, exports.
6. a kind of measuring method based on a kind of RLC measuring instrument described in any one in claim 2 to 4 according to claim 5, it is characterized in that: in described step 001, described CPLD control panel adopts direct digital frequency synthesis technology, produces and controls 20Hz ~ 1MHz sinusoidal detection signal be delivered to tested electronic devices and components through D/A converter, low pass filter blocks according to the control command receiving.
7. a kind of measuring method based on a kind of RLC measuring instrument described in any one in claim 2 to 4 according to claim 5, it is characterized in that: in described step 003, described CPLD control panel is controlled detecting circuit module pin and is carried out to the received signal, in two phase demodulation processes, adopting three road square waves to carry out phase demodulation to the voltage differential signal of tested electron device and standard resistor at two terminals.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109374971A (en) * | 2018-09-25 | 2019-02-22 | 北京工业大学 | Based on megahertz impedance measurement of embedded system |
| CN110542793A (en) * | 2019-08-07 | 2019-12-06 | 华南理工大学 | passive device intelligent equivalent circuit model, parameter measuring device and working method |
| CN114089040A (en) * | 2021-11-01 | 2022-02-25 | 苏州茂鼎电子科技有限公司 | Multichannel high-precision LCR test system |
| CN114371346A (en) * | 2022-03-22 | 2022-04-19 | 江苏游隼微电子有限公司 | Capacitance value detection circuit and detection method of capacitor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2118992U (en) * | 1992-02-15 | 1992-10-14 | 国家地震局地震研究所 | Frequency meter |
| CN101533047A (en) * | 2009-04-14 | 2009-09-16 | 江苏工业学院 | AC milliohm meter based on complex programmable logic device, and measurement method therefor |
| CN102201819A (en) * | 2011-03-07 | 2011-09-28 | 武汉理工大学 | Frequency synthesis source applied by DDS short-wave transmitter based on CPLD design |
| CN102508024A (en) * | 2011-09-20 | 2012-06-20 | 郑州轻工业学院 | Frequency and phase difference precision measurement method based on frequency and phase relationship auxiliary processing |
| US20130297236A1 (en) * | 2007-06-21 | 2013-11-07 | Commissariat A L'energie Atomique | Method for Detecting Defective Electrodes in a Micro-Electrode Matrix |
-
2014
- 2014-07-07 CN CN201410321835.7A patent/CN104142430A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2118992U (en) * | 1992-02-15 | 1992-10-14 | 国家地震局地震研究所 | Frequency meter |
| US20130297236A1 (en) * | 2007-06-21 | 2013-11-07 | Commissariat A L'energie Atomique | Method for Detecting Defective Electrodes in a Micro-Electrode Matrix |
| CN101533047A (en) * | 2009-04-14 | 2009-09-16 | 江苏工业学院 | AC milliohm meter based on complex programmable logic device, and measurement method therefor |
| CN102201819A (en) * | 2011-03-07 | 2011-09-28 | 武汉理工大学 | Frequency synthesis source applied by DDS short-wave transmitter based on CPLD design |
| CN102508024A (en) * | 2011-09-20 | 2012-06-20 | 郑州轻工业学院 | Frequency and phase difference precision measurement method based on frequency and phase relationship auxiliary processing |
Non-Patent Citations (3)
| Title |
|---|
| 李林 等: "FPGA与单片机在RLC测量系统设计中的应用", 《化工自动化及仪表》 * |
| 李燕民: "《电路和电子技术（下）》", 31 March 2004, 北京理工大学出版社 * |
| 高昆: "基于FPGA的便携式RLC参数测量仪设计", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109374971A (en) * | 2018-09-25 | 2019-02-22 | 北京工业大学 | Based on megahertz impedance measurement of embedded system |
| CN109374971B (en) * | 2018-09-25 | 2020-12-04 | 北京工业大学 | Megahertz impedance meter based on embedded system |
| CN110542793A (en) * | 2019-08-07 | 2019-12-06 | 华南理工大学 | passive device intelligent equivalent circuit model, parameter measuring device and working method |
| CN114089040A (en) * | 2021-11-01 | 2022-02-25 | 苏州茂鼎电子科技有限公司 | Multichannel high-precision LCR test system |
| CN114371346A (en) * | 2022-03-22 | 2022-04-19 | 江苏游隼微电子有限公司 | Capacitance value detection circuit and detection method of capacitor |
| CN114371346B (en) * | 2022-03-22 | 2022-05-24 | 江苏游隼微电子有限公司 | Capacitance value detection circuit and detection method of capacitor |
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