CN103675385A - Multi-channel sensing single-channel constant current measuring device - Google Patents

Multi-channel sensing single-channel constant current measuring device Download PDF

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Publication number
CN103675385A
CN103675385A CN201310697341.4A CN201310697341A CN103675385A CN 103675385 A CN103675385 A CN 103675385A CN 201310697341 A CN201310697341 A CN 201310697341A CN 103675385 A CN103675385 A CN 103675385A
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CN
China
Prior art keywords
circuit
constant current
channel
sensing
selection circuit
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Pending
Application number
CN201310697341.4A
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Chinese (zh)
Inventor
张伟
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JIANGXI QINGHUA TAIHAO MICRO MOTOR Co Ltd
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JIANGXI QINGHUA TAIHAO MICRO MOTOR Co Ltd
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Priority to CN201310697341.4A priority Critical patent/CN103675385A/en
Publication of CN103675385A publication Critical patent/CN103675385A/en
Pending legal-status Critical Current

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Abstract

The invention provides a multi-channel sensing single-channel constant current measuring device. The multi-channel sensing single-channel constant current measuring device comprises a plurality of sets of differential amplification circuits, a simulation selection circuit, a constant current filter circuit and a variable gain amplifying circuit, wherein each sensing signal is connected with the corresponding set of differential amplification circuit, the sensing signals are amplified in a differential amplification mode and then enter the simulation selection circuit, an AD converter of the simulation selection circuit is in a multi-channel input and single-channel output mode, the simulation selection circuit is connected with the constant current filter circuit, and the sensing signals filtered in a constant current mode pass through the variable gain amplifying circuit and enter an AD sampling chip to carry out sample measurement. The multi-channel sensing single-channel constant current measuring device is high in adaptability, stable and reliable in circuit, and capable of being applied to various paths of sensing signals at the same time, reducing the scale of sensing and measuring hardware circuits, lowering the component cost and improving the flexibility of testing hardware.

Description

A kind of multichannel sensing single channel constant current measurement mechanism
Technical field
The invention belongs to transducing signal field, be specifically related to a kind of multichannel sensing single channel constant current measurement mechanism.
Background technology
The measurement of transducing signal is main points and the difficult point in signal measurement often.In physical quantitys such as probe temperature, pressure, must be converted into the electrical quantity signal that resistance etc. can be measured by sensor just can measure.Yet what because resistance sizes and the resolving accuracy of the conversion of different sensing devices are not identical, every road signal all must carry out by the excitation of constant current source and by transforming, conditioning can receive for chip is the voltage signal of 0-3.3V.In this manner, need to not only increase device cost, and can cause sensing resistor for a long time in "on" position for current source of each Path Setup and modulate circuit, be unfavorable for the long-term stable operation of circuit, and increase system power dissipation.
Summary of the invention
The object of this invention is to provide a kind of analog switch that passes through, with single channel conditioning and measurement passage, measure the constant current measurement mechanism of multichannel transducing signal.
For achieving the above object, the technical solution adopted in the present invention is:
A kind of multichannel sensing single channel constant current measurement mechanism, comprise some groups of differential amplifier circuits, analog selection circuit, constant current filtering circuit, variable-gain amplification circuit, it is characterized in that: each road transducing signal respectively connects one group of differential amplifier circuit, transducing signal enters analog selection circuit after differential amplification, the AD converter of described analog selection circuit is the output of hyperchannel input single channel, analog selection circuit connects constant current filtering circuit, and the filtered transducing signal of constant current enters AD sampling A/D chip through variable-gain amplification circuit and carries out sampled measurements.
Described differential amplifier circuit is two differential amplifier circuits.
Described AD converter is MAX4581 converter.
Variable gain amplifier in described variable-gain amplification circuit is PGA204.
Technique effect of the present invention is: 1, strong adaptability, and circuit is reliable and stable, can be applied to multichannel transducing signal simultaneously; 2, can reduce the scale of sensing measurement hardware circuit, reduce device cost, increase the dirigibility of testing hardware.If 3 when enter without transducing signal, apparatus of the present invention can be ended energising, reduce the power consumption of device, have extended the serviceable life of device.
Accompanying drawing explanation
Fig. 1 is differential amplifier circuit of the present invention;
Fig. 2 is analog selection circuit of the present invention;
Fig. 3 is constant current filtering circuit of the present invention;
Fig. 4 is variable-gain amplification circuit of the present invention.
Accompanying drawing explanation: 1, AD converter 2, variable gain amplifier 3, AD sampling A/D chip.
Embodiment
Below by accompanying drawing, the present invention is described further.
A kind of multichannel sensing single channel constant current measurement mechanism, comprise some groups of differential amplifier circuits, analog selection circuit, constant current filtering circuit, variable-gain amplification circuit, it is characterized in that: each road transducing signal respectively connects one group of differential amplifier circuit, transducing signal enters analog selection circuit after differential amplification, the AD converter 1 of described analog selection circuit 2 is the output of hyperchannel input single channel, analog selection circuit connects constant current filtering circuit, and the filtered transducing signal of constant current enters AD sampling A/D chip 3 through variable-gain amplification circuit and carries out sampled measurements.
Described differential amplifier circuit is two differential amplifier circuits.
Described AD converter 1 is MAX4581 converter.
Variable gain amplifier 2 in described variable-gain amplification circuit is PGA204.
Differential amplifier circuit as shown in Figure 1, voltage reference is introduced the positive input terminal of amplifier J1 by R1, and J1 and J2 form constant-current device, and the signal of voltage reference forms steady current by constant-current device between AB point.Sensor is connected between 1, No. 2 terminal of J6, and current limit produces at A point the voltage signal matching with resistance after by resistance, and by being designated AD-1 for late-class circuit after the resistance R 12 connecting.When there being multichannel transducing signal to be greater than, repeat circuit shown in Fig. 1, be designated AD-2, AD-3......AD-X (X is not more than 8), be connected with the circuit of next stage.
Analog selection circuit as shown in Figure 2, transducing signal is after nursing one's health into the plurality of voltages signals such as AD-1, AD-2, and access analog selection circuit, on the basis of an AD passage of application, guarantees the measurement to multichannel transducing signal.Circuit after conditioning access IC1(AD converter 1) the pins such as 14,15, by the effect of IC1, switch analog channel with taking turns the mode turning, when not carrying out lane testing, analog channel is selected No. 13 pins of IC1, carries out error school zero, is then connected with the circuit of next stage.
Constant current filtering circuit as shown in Figure 3, the signal of selection is through No. 3 point outputs of IC1, and the voltage-controlled filtering circuit of second order forming by entering J3 after R2, carries out 10Hz low-pass filtering to front segment signal, and filtering completes the output by R5, is connected with the circuit of next stage.
Variable-gain amplification circuit as shown in Figure 4, the voltage signal of conditioning is because the difference of front end sensing resistor may differ larger after filtering, input now may be 100mV-2V, signal condition must be arrived the electric pressure of 2V-2.5V by the mode of amplifying in rear end, for AD sampling A/D chip 3, processes.Due to the difference of input range, need to carry out signal amplification by the adjusting of gain amplifier.IC2 is variable gain amplifier 2, and signal is from No. 5 point accesses of IC2, and 15, No. 16 points of IC2 are gain-adjusted control end, by changing this data of 2, change the output magnification ratio that IC211 is ordered.Data after amplification are introduced AD sampling A/D chip 3 after J4 next stage differential amplification.

Claims (4)

1. a multichannel sensing single channel constant current measurement mechanism, comprise some groups of differential amplifier circuits, analog selection circuit, constant current filtering circuit, variable-gain amplification circuit, it is characterized in that: each road transducing signal respectively connects one group of differential amplifier circuit, transducing signal enters analog selection circuit after differential amplification, the AD converter of described analog selection circuit is the output of hyperchannel input single channel, analog selection circuit connects constant current filtering circuit, and the filtered transducing signal of constant current enters AD sampling A/D chip through variable-gain amplification circuit and carries out sampled measurements.
2. a kind of multichannel sensing single channel constant current measurement mechanism according to claim 1, is characterized in that: described differential amplifier circuit is two differential amplifier circuits.
3. a kind of multichannel sensing single channel constant current measurement mechanism according to claim 1, is characterized in that: described AD converter is MAX4581 converter.
4. a kind of multichannel sensing single channel constant current measurement mechanism according to claim 1, is characterized in that: the variable gain amplifier in described variable-gain amplification circuit is PGA204.
CN201310697341.4A 2013-12-18 2013-12-18 Multi-channel sensing single-channel constant current measuring device Pending CN103675385A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201310697341.4A CN103675385A (en) 2013-12-18 2013-12-18 Multi-channel sensing single-channel constant current measuring device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201310697341.4A CN103675385A (en) 2013-12-18 2013-12-18 Multi-channel sensing single-channel constant current measuring device

Publications (1)

Publication Number Publication Date
CN103675385A true CN103675385A (en) 2014-03-26

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CN201310697341.4A Pending CN103675385A (en) 2013-12-18 2013-12-18 Multi-channel sensing single-channel constant current measuring device

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CN (1) CN103675385A (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080004536A1 (en) * 2006-06-30 2008-01-03 Baxi Amit S Method and apparatus for amplifying multiple signals using a single multiplexed amplifier channel with software controlled AC response
CN103105181A (en) * 2011-11-15 2013-05-15 瑞萨电子株式会社 Semiconductor device and sensor system
CN103106293A (en) * 2011-11-15 2013-05-15 瑞萨电子株式会社 Development support apparatus of semiconductor device and development support method
CN203642941U (en) * 2013-12-18 2014-06-11 江西清华泰豪微电机有限公司 Multipath sensing single-channel constant current measuring device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080004536A1 (en) * 2006-06-30 2008-01-03 Baxi Amit S Method and apparatus for amplifying multiple signals using a single multiplexed amplifier channel with software controlled AC response
CN103105181A (en) * 2011-11-15 2013-05-15 瑞萨电子株式会社 Semiconductor device and sensor system
CN103106293A (en) * 2011-11-15 2013-05-15 瑞萨电子株式会社 Development support apparatus of semiconductor device and development support method
CN203642941U (en) * 2013-12-18 2014-06-11 江西清华泰豪微电机有限公司 Multipath sensing single-channel constant current measuring device

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Application publication date: 20140326