CN102901549B - Driving, signal conditioning and acquisition device for strain resistance type pressure sensor - Google Patents

Abstract

The invention discloses a driving, signal conditioning and acquisition device for a strain resistance type pressure sensor. A precision voltage reference source and a positive-negative-positive (PNP) transistor switch are utilized to form a 10V constant voltage source to drive a strain resistance type sensor, and the constant voltage source ripple wave is smaller than 0.05mV. As for a signal conditioning part, a differential amplifier and a local grounding technology are utilized to achieve differential input, differential output and cascade connection of the differential amplifier, and thereby the common-mode noise of the amplifier cascade connection is reduced. A 24-bit analog-to-digital converter is utilized for collecting a pre-amplified signal and transmitting the digital signal to a microcontroller through a serial peripheral interface (SPI) serial communication protocol, and the microcontroller sends a measurement signal to a computer through a wireless communication module according to a serial communication interface (SCI) serial communication standard for integrated management. The driving, signal conditioning and acquisition device for the strain resistance type pressure sensor has the advantages that the high gain of 106 is achieved, the accuracy is high, the linear range is wide, the gain-programmed automatic adjustment and wireless data transmission are achieved, and the noise, the power consumption and the cost are low.

Description

For the driving of strain resistance type pressure transducer, signal condition and harvester

Technical field

The present invention relates to precision electronic device field, specifically, be a kind of driving for strain resistance type pressure transducer, signal condition and harvester, use with the strain resistance type sensor matching of ten thousand/precision, effectively can improve the precision of strain resistance type sensor.

Background technology

Strain resistance type pressure transducer utilizes strain-type shift theory, resistance strain plate or strain film can be supported, the strain produced when measuring object receiving force or moment can be experienced, and strain variation is converted to resistance variations, the change of voltage or electric current is converted to further by electric bridge.The scales utilizing strain-type shift theory to realize is strain gauge transducer.

The resistance strain gage of current application mainly contains metal wire type foil gauge, metal foil stain gauge, semiconductor gauge and film metal foil gauge.

For metallic resistance silk, strain-type shift theory is described below.

Cross section is the resistance value of the metallic resistance silk of circle:

$R=\frac{\mathrm{L\ρ}}{S}=\frac{\mathrm{L\ρ}}{\mathrm{\π}{r}^2}$

In formula, R is resistance value (Ω), ρ be resistivity (Ω m), L be length m, S wiry is cross-sectional area m wiry ², r is section radius m wiry.When extending dL when one section of metallic resistance silk under tension, its cross-sectional area by corresponding minimizing dS, resistivity then because of metal lattice distortion factor impact also will change d ρ, thus cause resistance wiry change dR be:

$\mathrm{dR}=\frac{L}{{\mathrm{\πr}}^2}\mathrm{d\ρ}+\frac{\mathrm{\ρ}}{\mathrm{\π}{r}^2}\mathrm{dL}-2\frac{\mathrm{\ρL}}{\mathrm{\π}{r}^2}\mathrm{dr}$

Then:

$\frac{\mathrm{dR}}{R}=K_0\mathrm{dL}/L$

In formula, K ₀represent the gage factor of metal material, K ₀representation unit strains the resistance change rate caused.Determined by material properties.

As seen from the above analysis, strain resistance type sensor can experience the strain of its resistance strain plate supported or strain film generation, and obtain the relative change of resistance, usually by electric bridge, the change of resistance can be changed into voltage or electric current letter, the type of drive of electric bridge is divided into constant voltage to drive or constant current drives.

Strain gauge transducer is the core component of widespread use in electronic scale.Electronic scale generally refers to the weighing apparatus that electronic installation is housed, and is the important means of automatic weighting control and Trade Measures, all serves vital role to reinforcement business administration, strict production, trade settlement, communications and transportation and scientific research.There is reaction velocity fast, measurement range is wide, wide application, structure are simple, it is easy to operate to use, the signal is far passed, be convenient to the features such as computing machine control.Be widely used in the every field such as coal, oil, chemical industry, electric power, light industry, metallurgy, mine, communications and transportation, harbour, building, machine-building and national defence.With the development of society, have higher requirement to tonometric precision in each field.The technical indicator of domestic and international pressure transducer is given in following table 1, and manufacturer.

Table 1:

Current as can be seen from Table 1, international by 0.015% precision LOAD CELLS commercialization, and the precision level of the core sensor of domestic weighing apparatus manufacturer the highest only have 0.02% generally apply precision 0.5%, even high-precision electronic scale, its core sensor also depends on import.Therefore development has the electronic scale of China's independent intellectual property right and signal condition system has great Social and economic benef@.

Summary of the invention

For the deficiencies in the prior art, the present invention proposes a kind of low cost, high precision, the integration driving for strain resistance type pressure transducer of high reliability, signal condition and harvester, adopt constant voltage type of drive, avoid the feedback element that complex modules when constant current drives and constant current drive.

The present invention is used for the driving of strain resistance type pressure transducer, signal condition and harvester, comprises high-accuracy and constant potential source, prime amplifier, analog-to-digital conversion module, microcontroller and wireless communication module.

Wherein, high-accuracy and constant potential source is used for actuation performance resistance sensor, for forming 10V constant pressure source by reference voltage source chip REF102 and PNP transistor switch 2N2905 and current-limiting resistance R1; Wherein, No. 2 pins of reference voltage source chip REF102 are connected with the base stage of PNP transistor switch 2N2905, are also connected with 12V direct supply anode by current-limiting resistance R1 simultaneously; No. 4 pin ground connection of reference voltage source chip REF102; The emitter of PNP transistor switch 2N2905 is connected with 12V direct supply anode, collector is connected with No. 6 pins of reference voltage source chip REF102 jointly as the output terminal of driving circuit, is connected respectively with the positive and negative terminal of the power supply of strain resistance type pressure transducer.

Described prime amplifier adopts the differential signal exported strain resistance type sensor to carry out amplifying signal conditioning mode, is made up of AD620 chip and AD705 chip, feedback resistance RF and resistance R2 and resistance R3.

Wherein, in AD620 chip: No. 2 pins are connected with strain resistance type sensor output respectively with No. 3 pins, as forward, the reverse input end of the differential signal that strain resistance type sensor exports; No. 7 pins connect 10V power positive end; No. 4 pin ground connection; No. 6 pins are as the positive pole of prime amplifier output terminal; No. 1 pin is all connected with feedback resistance RF with No. 8 pins.

In AD705 chip: No. 2 pins are all connected with No. 5 pins of AD620 chip with No. 6 pins, form local earth thus; No. 3 pins are connected with the common port of resistance R3 with resistance R2; Wherein, the other end of resistance R3 is all connected with the positive pole of 10V power supply with No. 7 pins; The other end of resistance R2 is connected with No. 2 pins; No. 4 pin ground connection; No. 6 pins are as the negative pole of amplifier out.

Forward, the reverse input end of prime amplifier are connected with the differential signal outputs of strain resistance type pressure transducer respectively.Analog input end positive pole in the negative pole of output end of prime amplifier and analog conversion module, and the negative pole of output end of prime amplifier also with is in analog connected, and be connected by inductance and the power supply in analog-to-digital conversion module; The positive pole of output terminal is connected with the analog input end negative pole of analog-to-digital conversion module, makes the positive pole of the output terminal of prime amplifier export as single-ended signal thus, can directly be coupled with analog-to-digital conversion module like this.

Described analog-to-digital conversion module adopts the differential signal of 24 analog to digital converter collections after preposition direct current amplifier amplifies, and is converted into digital signal and is delivered to microcontroller by SPI serial communication protocol; In the present invention, the concrete structure of analog-to-digital conversion module is: analog-to-digital conversion module is by the analog to digital converter chip CS5532 of the high integration as core; In analog to digital converter chip CS5532, No. 2 pins are used as the analog input end negative pole of analog-to-digital conversion module; No. 1 pin simulation input anode of modulus conversion chip CS5532; No. 9 pins, No. 10 pins are all connected with crystal oscillator; No. 5 pins are connected with No. 15 pins by resistance R4, and are connected with 5V power supply; No. 5 pins, No. 15 pins also connect power supply ground respectively by a decoupling capacitor; No. 3 pins, No. 4 pins are connected by electric capacity C1; No. 16 pins are connected with No. 6 pins; No. 6 pins connect power supply ground; No. 7 pins, No. 8 pins are connected with the I/O port of microcontroller; 11 ~ No. 14 pins are connected with the SPI serial communication end of microcontroller.

Measuring-signal exports with SCI standard for serial communication by described wireless communication module, is connected, realizes wireless penetration control and the data acquisition of industry spot by serial port data line with microcontroller; Measuring-signal is exported with SCI standard for serial communication by wireless transmission/reception module by microcontroller; Described microcontroller adopts XS128_MAL series 16 8-digit microcontrollers.

The invention has the advantages that:

1, driving of the present invention, signal condition and harvester have high-gain 10 ⁶, high precision, the wide range of linearity, programmable gain regulates automatically, Wireless Data Transmission, low noise, low-power consumption, the feature of low cost.

2, driving of the present invention, signal condition and harvester and high precision strain resistance type sensor matching use, and the electronic weighing system precision of formation is improved;

3, in driving of the present invention, signal condition and harvester, prime amplifier can be used for rear class cascade by output difference sub-signal, and also exportable single-ended signal is directly connected with analog to digital converter; Prime amplifier single-stage maximum amplification is 1000.

Accompanying drawing explanation

Fig. 1 is driving of the present invention, signal condition and harvester one-piece construction block diagram; Circuit diagram;

Fig. 2 is high-accuracy and constant source circuit figure in driving of the present invention, signal condition and harvester;

Fig. 3 is preamplifier circuit figure in driving of the present invention, signal condition and harvester;

Fig. 4 is analog-to-digital conversion module circuit diagram in driving of the present invention, signal condition and harvester;

Fig. 5 is electric capacity C2 connected mode figure in driving of the present invention, signal condition and harvester;

Fig. 6 is driving of the present invention, signal condition and harvester one-piece construction circuit diagram;

Fig. 7 be when there is in driving of the present invention, signal condition and harvester 2 prime amplifiers between connected mode figure.

Embodiment

Below in conjunction with accompanying drawing, the invention will be further described.

The present invention is used for the driving of strain resistance type pressure transducer, signal condition and harvester, comprises high-accuracy and constant potential source, prime amplifier, analog-to-digital conversion module, microcontroller and wireless communication module, as shown in Figure 1.

Wherein, high-accuracy and constant potential source is used for actuation performance resistance sensor, and known through Theory of Circuit Analysis, the fluctuation of bridge-drive voltage will cause the fluctuation of electric bridge nonequilibrium condition output difference sub-signal, thus increases the instability measured; And the supply voltage suitably increasing electric bridge can improve the sensitivity of sensor, therefore a kind of high-precision constant pressure source serves very important effect in strain resistance type pressure transducer.Thus, in the present invention, high-accuracy and constant potential source forms 10V constant pressure source by as the reference voltage source chip REF102 of core and the current-limiting resistance R1 of PNP transistor switch 2N2905 and 50 ~ 200 Ω, as shown in Figure 2; Wherein, No. 2 pins of reference voltage source chip REF102 are connected with the base stage of PNP transistor switch 2N2905, are also connected with 12V direct supply anode by current-limiting resistance R1 simultaneously; No. 4 pin ground connection (power supply negative terminal) of reference voltage source chip REF102; The emitter of PNP transistor switch 2N2905 is connected with 12V direct supply anode, collector is connected jointly as the output terminal of driving circuit with No. 6 pins of reference voltage source chip REF102, be connected with the positive and negative terminal of the power supply of strain resistance type pressure transducer respectively, as shown in Figure 6.The resistance magnitude range of above-mentioned current-limiting resistance R1 is 50 ~ 200 Ω, and the resistance size of current-limiting resistance R1 depends on required driving power, and experimental formula is: maximum output current I _max=20V/ resistance.In the present invention, the resistance of current-limiting resistance R1 is 100 Ω, and make the constant pressure source ripple of the high-accuracy and constant potential source of said structure be less than 0.05mV, peak power output reaches 2W, and ripple is less than 0.05mV.

Described prime amplifier is used for nursing one's health the faint differential signal that strain resistance type pressure transducer exports, and be converted to the metastable signal that can be gathered by analog-to-digital conversion module, usual signal condition mode comprises amplification, filtering, modulation and demodulation etc.Prime amplifier of the present invention adopts the differential signal exported strain resistance type sensor to carry out amplifying signal conditioning mode, be convenient to the cascade of prime amplifier, form by as the AD620 chip of core and AD705 chip, feedback resistance RF and 20K Ω resistance R2 and 30K Ω resistance R3, as shown in Figure 3; Wherein, in AD620 chip: No. 2 pins are connected with strain resistance type sensor output respectively with No. 3 pins, as forward, the reverse input end of the differential signal that strain resistance type sensor exports; No. 7 pins connect 10V power positive end; No. 4 pin ground connection (power supply negative terminal); No. 6 pins are as the positive pole of prime amplifier output terminal; No. 1 pin is all connected with feedback resistance RF with No. 8 pins, is adjusted the enlargement factor of prime amplifier by feedback resistance RF, and the feedback resistance RF resistance that different amplification is selected is as shown in table 2 below.

The preposition direct current amplifier enlargement factor of table 2 and feedback resistance value relatable

Feedback resistance resistance (Ω)	Gain	Feedback resistance resistance (Ω)	Gain
				49.9K	1.990	1.00K	50.40
12.4K	4.984	499	100.0
				5.49K	9.998	100	495.0
2.61K	19.93	49.9	991.0

In AD705 chip: No. 2 pins are all connected with No. 5 pins of AD620 chip with No. 6 pins, form local earth (Local Ground) thus; No. 3 pins are connected with the common port of resistance R3 with resistance R2; Wherein, the other end of resistance R3 is all connected with the positive pole of 10V power supply with No. 7 pins; The other end of resistance R2 is connected with No. 2 pins; No. 4 pin ground connection; No. 6 pins are as the negative pole of amplifier out.

As shown in Figure 6, the forward of prime amplifier, reverse input end are connected with the differential signal outputs of strain resistance type pressure transducer respectively.Analog input end positive pole in the negative pole of output end of prime amplifier and analog conversion module, and the negative pole of output end of prime amplifier also with is in analog connected, and by inductance value be the inductance of 10uH with the power supply in analog-to-digital conversion module be connected; The positive pole of output terminal is connected with the analog input end negative pole of analog-to-digital conversion module, makes the positive pole of the output terminal of prime amplifier export as single-ended signal thus, can directly be coupled with analog-to-digital conversion module like this.

In the present invention strain resistance type pressure transducer with can be connected n prime amplifier between analog-to-digital conversion module, n >=1; When the enlargement factor not high (being less than 1000 times) that strain resistance type pressure transducer sensor needs, then only need a prime amplifier to carry out one-level to faint differential signal in driving of the present invention, signal condition and harvester to amplify, n=1, prime amplifier is connected with strain resistance type pressure transducer, analog-to-digital conversion module by above-mentioned connected mode.When the enlargement factor very high (being greater than 1000 times) that sensor needs, the differential signal exported after a prime amplifier carries out one-level amplification may can't meet system requirements, multiple prime amplifier can be accessed thus between prime amplifier and analog-to-digital conversion module, i.e. n > 1, realize carrying out 2 ~ n level to the differential signal of strain resistance type Output pressure to amplify, that the faint differential signal enlargement factor that sensor exports can be carried like this is higher.Now, between strain resistance type pressure transducer and prime amplifier, and between prime amplifier with analog-to-digital conversion module, same employing aforesaid way connects.And the connected mode between two prime amplifiers is: the output head anode of previous prime amplifier, negative pole are connected with the input anode of a rear prime amplifier, negative pole respectively, as shown in Figure 7.In reality, the selection of the number n of prime amplifier needs relevant according to the amplitude of the output signal of strain resistance type pressure transducer.

Described analog-to-digital conversion module adopts the differential signal (simulating signal) of 24 analog to digital converter collections after preposition direct current amplifier amplifies, and is converted into digital signal and is delivered to microcontroller by SPI serial communication protocol.In the present invention, the concrete structure of analog-to-digital conversion module is:

Analog-to-digital conversion module is by the analog to digital converter chip CS5532 of the high integration as core, owing to having used charge balance technique, its performance can reach 24, is applicable to very much the list/bipolarity small-signal measuring the applications such as weighing instrument, process control, science and medical treatment.As shown in Figure 4, analog to digital converter CS5532 has 2 passages can for choosing, and there is the chopper-stabilized instrumentation amplifier (6nV/Hz@0.1Hz) of a pole low noise inside, and its gain may be selected to be 1X, 2X, 4X, 8X, 16X, 32X and 64X.This analog to digital converter inside also has the Δ ∑ modulator on 4 rank, thereafter follow a digital filter, it provides 20 kinds of alternative output word speed: 6.25,7.5,12.5,15,25,30,50,60,100,120,200,240,400,480,800,960,1600,1920,3200 and 3840Sps(MCLK=4.9152MHz).Communication conveniently and between microprocessor, it is inner also have one with the 3-line serial interface of SPI and Microwire compatibility, have a Schmidt trigger at serial clock mouth (SCLK).Analog to digital converter chip CS5532 has high dynamic range, output word speed able to programme and the advantage such as power configuration option flexibly.

In analog to digital converter chip CS5532, No. 2 pins are used as the analog input end negative pole of analog-to-digital conversion module.No. 1 pin of modulus conversion chip is the analog input end positive pole of analog-to-digital conversion module.For direct current signal, the electric capacity C2 of 50 ~ 100uF can be added between No. 2 pin of 1, of CS5532, as shown in Figure 5, like this can filtering difference letter in high frequency noise components.But this can cause the reduction of the real-time of Circuit responce, the selection for the higher circuit capacitance of real-time at 0 ~ 1uF, namely should reduce the capability value of electric capacity C2 or does not add electric capacity; No. 9 pins, No. 10 pins are all connected with 4.0592MHz crystal oscillator; No. 5 pins are connected with No. 15 pins by 10 Ω resistance R4, and are connected with 5V power supply; No. 5 pins, No. 15 pins also connect power supply ground respectively by a 0.1uF decoupling capacitor; No. 3 pins, No. 4 pins are connected by 22nF electric capacity; No. 16 pins are connected with No. 6 pins.No. 6 are drawn corner connection power supply ground; No. 7 pins, No. 8 pins are connected with the I/O port of microcontroller, thus by the duty of microprocessor controls modulus conversion chip CS5532; 11 ~ No. 14 pins are connected with the SPI serial communication end of microcontroller, transmit analog-to-digital result thus and control analog-digital conversion process to microcontroller.

As shown in Figure 6, described microcontroller adopts XS128_MAL series 16 8-digit microcontrollers, and this microcontroller has the bus speed of 40MHz; There is 64KB, 128KB and 256KB flash memory option, all with error code error correction (ECC); With ECC, 4KB to 8KB DataFlash, store for realizing data or program; Configure 12 analog to digital converters, the switching time of 3 μ s can be realized; Support control area net (CAN), local internet (LIN) and Serial Peripheral Interface (SPI) (SPI) agreement, serial data interface (SCI) agreement; With 16 digit counters, 8 passage timers; Outstanding EMC/ runs and stops current capability.

Adopt wireless communication module to be exported with SCI standard for serial communication by measuring-signal in invention, be connected with microcontroller by serial port data line.Wireless penetration control and the data acquisition of industry spot can be realized.Measuring-signal is exported with SCI standard for serial communication by wireless transmission/reception module by microcontroller.Described wireless communication module working carrier frequency frequency is the open ISM band of 431MHz ~ 436MHz, exempts from licence and uses; Micro-emissive power, maximum transmission power 10mW(10dBm); Antijamming capability is strong, and adopt forward error correction coding, the actual bit error rate is low reaches 10-5 ~ 10-6; Long transmission distance, in sighting distance situation, antenna placement location is higher than 2m, and transmitting distance can reach 1000m(BER=10-3/1200bps), transmitting distance is greater than 700m(BER=10-3/4800bps), transmitting distance is greater than 500m(BER=10-3/9600bps).

Claims (7)

1., for the driving of strain resistance type pressure transducer, signal condition and harvester, it is characterized in that: comprise high-accuracy and constant potential source, prime amplifier, analog-to-digital conversion module, microcontroller and wireless communication module;

Wherein, high-accuracy and constant potential source is used for actuation performance resistance sensor, for forming 10V constant pressure source by reference voltage source chip REF102 and PNP transistor switch 2N2905 and current-limiting resistance R1; Wherein, No. 2 pins of reference voltage source chip REF102 are connected with the base stage of PNP transistor switch 2N2905, are also connected with 12V direct supply anode by current-limiting resistance R1 simultaneously; No. 4 pin ground connection of reference voltage source chip REF102; The emitter of PNP transistor switch 2N2905 is connected with 12V direct supply anode, collector is connected with No. 6 pins of reference voltage source chip REF102 jointly as the output terminal of driving circuit, is connected respectively with the positive and negative terminal of the power supply of strain resistance type pressure transducer;

The Standard resistance range of described current-limiting resistance R1 is 50 ~ 200 Ω, and make the constant pressure source peak power output of high-accuracy and constant potential source reach 2W, ripple is less than 0.05mV;

Described prime amplifier adopts the differential signal exported strain resistance type sensor to carry out amplifying signal conditioning mode, is made up of AD620 chip and AD705 chip, feedback resistance RF and resistance R2 and resistance R3;

Wherein, in AD620 chip: No. 2 pins are connected with strain resistance type sensor output respectively with No. 3 pins, as forward, the reverse input end of the differential signal that strain resistance type sensor exports; No. 7 pins connect 10V power positive end; No. 4 pin ground connection; No. 6 pins are as the positive pole of prime amplifier output terminal; No. 1 pin is all connected with feedback resistance RF with No. 8 pins;

In AD705 chip: No. 2 pins are all connected with No. 5 pins of AD620 chip with No. 6 pins, form local earth thus; No. 3 pins are connected with the common port of resistance R3 with resistance R2; Wherein, the other end of resistance R3 is all connected with the positive pole of 10V power supply with No. 7 pins; The other end of resistance R2 is connected with No. 2 pins; No. 4 pin ground connection; No. 6 pins are as the negative pole of amplifier out;

Forward, the reverse input end of prime amplifier are connected with the differential signal outputs of strain resistance type pressure transducer respectively; Analog input end positive pole in the negative pole of output end of prime amplifier and analog conversion module, and the negative pole of output end of prime amplifier also with is in analog connected, and be connected by inductance and the power supply in analog-to-digital conversion module; The positive pole of output terminal is connected with the analog input end negative pole of analog-to-digital conversion module, makes the positive pole of the output terminal of prime amplifier export as single-ended signal thus, can directly be coupled with analog-to-digital conversion module like this;

Strain resistance type pressure transducer be connected n prime amplifier between analog-to-digital conversion module, n >=1; Described analog-to-digital conversion module adopts the differential signal of 24 analog to digital converter collections after preposition direct current amplifier amplifies, and is converted into digital signal and is delivered to microcontroller by SPI serial communication protocol; The concrete structure of analog-to-digital conversion module is: analog-to-digital conversion module is by the analog to digital converter chip CS5532 of the high integration as core; In analog to digital converter chip CS5532, No. 2 pins are used as the analog input end negative pole of analog-to-digital conversion module; No. 1 pin simulation input anode of modulus conversion chip CS5532; No. 9 pins, No. 10 pins are all connected with crystal oscillator; No. 5 pins are connected with No. 15 pins by resistance R4, and are connected with 5V power supply; No. 5 pins, No. 15 pins also connect power supply ground respectively by a decoupling capacitor; No. 3 pins, No. 4 pins are connected by electric capacity C1; No. 16 pins are connected with No. 6 pins; No. 6 pins connect power supply ground; No. 7 pins, No. 8 pins are connected with the I/O port of microcontroller; 11 ~ No. 14 pins are connected with the SPI serial communication end of microcontroller; Described electric capacity C1 is 22nF;

Measuring-signal exports with SCI standard for serial communication by described wireless communication module, is connected, realizes wireless penetration control and the data acquisition of industry spot by serial port data line with microcontroller; Measuring-signal is exported with SCI standard for serial communication by wireless transmission/reception module by microcontroller; Described microcontroller adopts XS128_MAL series 16 8-digit microcontrollers.

2. the driving for strain resistance type pressure transducer as claimed in claim 1, signal condition and harvester, is characterized in that: the resistance of described current-limiting resistance R1, resistance R2, resistance R3, resistance R4 is respectively 100 Ω, 20K Ω, 30K Ω, 10 Ω.

3. the driving for strain resistance type pressure transducer as claimed in claim 1, signal condition and harvester, is characterized in that: the inductance value of described inductance is 10uH.

4. the driving for strain resistance type pressure transducer as claimed in claim 1, signal condition and harvester, is characterized in that: described decoupling capacitor connects as 0.1uF.

5. the driving for strain resistance type pressure transducer as claimed in claim 1, signal condition and harvester, is characterized in that: described crystal oscillator is 4.0592MHz.

6. the driving for strain resistance type pressure transducer as claimed in claim 1, signal condition and harvester, it is characterized in that: the electric capacity C2 connecting 50 ~ 100uF between 1, No. 2 pin of described modulus conversion chip CS5532, the high frequency noise components in the letter of filtering difference thus.

7. the driving for strain resistance type pressure transducer as claimed in claim 6, signal condition and harvester, is characterized in that: described electric capacity C2 is 0 ~ 1uF.