CN105758438A - Quick calibration device for LVDT signal demodulation circuit - Google Patents
Quick calibration device for LVDT signal demodulation circuit Download PDFInfo
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- CN105758438A CN105758438A CN201610122724.2A CN201610122724A CN105758438A CN 105758438 A CN105758438 A CN 105758438A CN 201610122724 A CN201610122724 A CN 201610122724A CN 105758438 A CN105758438 A CN 105758438A
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- operational amplifier
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- lvdt
- dual pathways
- band switch
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D18/00—Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
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- General Physics & Mathematics (AREA)
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Abstract
The invention discloses a quick calibration device for an LVDT signal demodulation circuit, and the device comprises a direct digital-type frequency synthesizer, a double-channel operational amplifier, a band switch, parameter adjusting resistors, a collection terminal, and a display terminal. The device is characterized in that the direct digital-type frequency synthesizer is connected with the double-channel operational amplifier; the double-channel operational amplifier, and is connected with a to-be-detected demodulation circuit; the to-be-detected demodulation circuit is connected with the collection terminal; the collection terminal is connected with the display terminal; the double-channel operational amplifier is connected with the band switch; and the waveband switch is connected with the parameter adjusting resistors. According to the invention, the device selects six groups of constant-value resistors as the parameter adjusting resistors of the double-channel operational amplifier, achieves the switching of the constant-value resistors through the band switch, and achieves the precise and quick measurement of a typical value.
Description
Technical field
The present invention relates to the fast calibration device of a kind of LVDT signal demodulating circuit, it is achieved LVDT signal demodulating circuit quickly calibrated.
Background technology
LVDT (linear change differential transformers) is a kind of general-purpose device for position measurement, possesses that the measurement range of linearity is big, the plurality of advantages such as contactless, reliability is high, anti-pollution of moving, and is widely used in the fields such as servo, numerical control, aviation.In actual use, LVDT exports signal is AC differential signal, it is impossible to be made directly acquisition process, generally adopts demodulator circuit that ac voltage signal is changed into the d. c. voltage signal being directly proportional to position.Owing to LVDT adopts without rub measurement mode, it is made to have unlimited resolution and unlimited mechanical life in theory, so the resolution of demodulator circuit often determines LVDT and uses resolution really, demodulator circuit is carried out accurate calibration and also becomes the key issue of LVDT displacement measurement system.
At present, the method realizing the calibration of LVDT signal demodulating circuit both at home and abroad mainly has following several:
1) adopt high precision measuring instrument point-to-point measurement component parameter value, contrast with design theory value；
2) utilize 2 road D/A converters, generate the 2 quasi-LVDT secondary coil signals of road sign, signal is injected LVDT signal demodulating circuit to be detected, magnitude of voltage after output demodulation, utilizes high-accuracy voltage to measure this magnitude of voltage of apparatus measures, contrast with theoretical value；
3) utilize signal generating device and 2 tunnel dual pathways operational amplifiers (abbreviation amplifier), utilize 2 potentiometers that amplifier is adjusted ginseng, generate the 2 quasi-LVDT secondary coil signals of road sign, utilize high-accuracy voltage to measure magnitude of voltage after apparatus measures demodulates, contrast with theoretical value.
In 3 kinds of above-mentioned methods, method 1 cannot realize automatization and calibration process complexity, and method 2 is difficult to solve Phase synchronization problem, and method 3 regulates potentiometer and causes that demodulating process is complicated, reliability is excessively poor.
Summary of the invention
LVDT is a electronic product as shown in Figure 1, and its working method is when iron core is moved to both sides by centre, and the difference in voltage of two secondary coil outputs is moved into linear relationship with iron core, and the voltage sum of two secondary coil outputs is a constant.The present invention makes improvements on the basis of preceding method 3, it is provided that the fast calibration device of a kind of LVDT signal demodulating circuit.
The present invention is realized by following technical proposals.A kind of fast calibration device of LVDT signal demodulating circuit, including DDS(Direct Digital Synthesizer), dual pathways operational amplifier, band switch, tune ginseng resistance, acquisition terminal, display terminal, DDS connects dual pathways operational amplifier, dual pathways operational amplifier connects demodulator circuit to be detected, demodulator circuit to be detected connects acquisition terminal, acquisition terminal connects display terminal, and dual pathways operational amplifier connects band switch, and band switch connects adjusts ginseng resistance.
More specifically, select 6 groups of fixed value resistances as the tune ginseng resistance of dual pathways operational amplifier.
The technique effect of the present invention: the motion of iron core is less than time within the scope of coil mechanism as shown in Figure 1, LVDT output has the significantly high linearity, only need to choose one group of representative value (generally containing LVDT maximum output voltage and total null voltage) measurement and can meet calibration requirements during calibration.Therefore use high accuracy fixed value resistance to replace potentiometer, solve that method 3 calibration accuracy is poor, poor reliability and the problem that regulates the calibration process complexity that potentiometer brings.
Accompanying drawing explanation
Fig. 1 is LVDT direct current output characteristics figure.
Fig. 2 is principles of the invention figure.
Fig. 3 is circuit diagram of the present invention.
Detailed description of the invention
As shown in Figure 2, a kind of fast calibration device of LVDT signal demodulating circuit, including DDS1, dual pathways operational amplifier 2, band switch, tune ginseng resistance, acquisition terminal, display terminal, DDS1 connects dual pathways operational amplifier 2, dual pathways operational amplifier 2 connects demodulator circuit 3 to be detected, demodulator circuit 3 to be detected connects acquisition terminal 4, acquisition terminal 4 connects display terminal 5, dual pathways operational amplifier 2 connects band switch 7, band switch 7 connects adjusts ginseng resistance 6, selects 6 groups of fixed value resistances as the tune ginseng resistance 6 of dual pathways operational amplifier 2.
Select 1 group of DDS1(Direct Digital Synthesizer) produce that 2 tunnel amplitudes are identical, the standard sine signal of phase contrast 180 °, utilize 1 dual pathways operational amplifier 2 respectively 2 groups of sinusoidal signals to be made processing and amplifying.Select 6 groups of fixed value resistances as the tune ginseng resistance 6 of amplifier, switch fixed value resistance by band switch 7 and realize accurately quickly measuring representative value.
This device DDS1 selects the AD9834 of AD company.AD9834 is a 75MHz, low-power consumption DDS device, it is possible to produce high-performance sine wave and triangular wave output.AD9834 provides phase-modulation and frequency modulation function.Frequency register is 28；When clock rate is 1MHz, AD9834 can realize the resolution of 0.004Hz.When supply voltage is 3V, its power consumption is only 20mW, is especially suitable for simulation LVDT standard signal.
This device dual pathways operational amplifier 2 selects LM148J.LM148J is a versatility army grade high-quality dual pathways operational amplifier, it is adaptable to this system.
Produce by AD9834 that AD9834+, AD9834-two-way amplitude is identical, the standard sine signal of phase contrast 180 °, utilize LM148J dual pathways operational amplifier respectively AD9834+, AD9834-2 group signal to be made processing and amplifying.R43, R53, R54, R46, R55, R56 is selected to join resistance as the tune of amplifier, selected by band switch, generating two-way IN+, IN-two-way difference amplitude, phase contrast 180 °, frequency is the LVDT sensor Simulation signal of 1.8KHz, the typical voltage values of simulation LVDT sensor output.Circuit realiration is shown in Fig. 3.
IN+, IN-two paths of differential signals in figure being injected in LVDT signal demodulating circuit, utilize high-accuracy voltage to measure instrument or Acquisition Circuit gathers demodulator circuit output voltage, contrast theoretical value can realize the tune of LVDT signal demodulating circuit is proofreaded standard.
Without advanced/time delay process in hardware circuit, select device concordance good, signal phase will not be caused to change.
Claims (2)
1. the fast calibration device of a LVDT signal demodulating circuit, including Direct Digital Synthesizer, dual pathways operational amplifier, band switch, tune ginseng resistance, acquisition terminal, display terminal, it is characterized in that: Direct Digital Synthesizer connects dual pathways operational amplifier, dual pathways operational amplifier connects demodulator circuit to be detected, demodulator circuit to be detected connects acquisition terminal, acquisition terminal connects display terminal, dual pathways operational amplifier connects band switch, and band switch connects adjusts ginseng resistance.
2. the fast calibration device of LVDT signal demodulating circuit according to claim 1, it is characterised in that: select 6 groups of fixed value resistances as the tune ginseng resistance of dual pathways operational amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610122724.2A CN105758438A (en) | 2016-03-04 | 2016-03-04 | Quick calibration device for LVDT signal demodulation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610122724.2A CN105758438A (en) | 2016-03-04 | 2016-03-04 | Quick calibration device for LVDT signal demodulation circuit |
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| Publication Number | Publication Date |
|---|---|
| CN105758438A true CN105758438A (en) | 2016-07-13 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610122724.2A Pending CN105758438A (en) | 2016-03-04 | 2016-03-04 | Quick calibration device for LVDT signal demodulation circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111006575A (en) * | 2019-12-06 | 2020-04-14 | 江西洪都航空工业集团有限责任公司 | Linear variable differential transformer signal generating device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0768515A1 (en) * | 1995-10-16 | 1997-04-16 | Texas Instruments Inc. | Variable differential transformer apparatus and method |
| CN2871853Y (en) * | 2005-11-11 | 2007-02-21 | 南京科远控制工程有限公司 | Valve-level controller |
| CN101561351A (en) * | 2009-06-04 | 2009-10-21 | 中国航空工业集团公司西安飞机设计研究所 | Airplane engine dynamic simulation test bed |
| CN104748655A (en) * | 2015-03-05 | 2015-07-01 | 江西洪都航空工业集团有限责任公司 | Device and method for quickly calibrating LVDT signal demodulation circuit |
-
2016
- 2016-03-04 CN CN201610122724.2A patent/CN105758438A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0768515A1 (en) * | 1995-10-16 | 1997-04-16 | Texas Instruments Inc. | Variable differential transformer apparatus and method |
| CN2871853Y (en) * | 2005-11-11 | 2007-02-21 | 南京科远控制工程有限公司 | Valve-level controller |
| CN101561351A (en) * | 2009-06-04 | 2009-10-21 | 中国航空工业集团公司西安飞机设计研究所 | Airplane engine dynamic simulation test bed |
| CN104748655A (en) * | 2015-03-05 | 2015-07-01 | 江西洪都航空工业集团有限责任公司 | Device and method for quickly calibrating LVDT signal demodulation circuit |
Non-Patent Citations (2)
| Title |
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| 刘涛等: "一种用于发动机仿真平台的线性可变差动变压器模拟器的设计", 《计算机测量与控制》 * |
| 康晓东等: "一种自监控差动变压传感器模拟平台的设计", 《航空计算技术》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111006575A (en) * | 2019-12-06 | 2020-04-14 | 江西洪都航空工业集团有限责任公司 | Linear variable differential transformer signal generating device |
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Application publication date: 20160713 |
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