CN205280206U - Capacitanc triaxial integration vibration sensor - Google Patents

Abstract

The utility model provides a capacitanc triaxial integration vibration sensor, includes: the little accelerometer of capacitanc silicon, filter circuit, separate directly and biasing amplifier circuit, power supply circuit, silicon capacitance formula accelerometer turns into voltage signal and output with the vibration signal, and its output is connected with filter circuit's input, filter circuit adopts eight rank low passes ellipse switch capacitive filter and RC circuit, and the voltage signal who inputs silicon capacitance formula accelerometer carries out filtering, and filter circuit exports and inputs continuously at a distance from the straight amplifier circuit that offsets that reaches, separate directly and biasing amplifier circuit filtering DC voltage weight, obtain 0V~5V's voltage signal and output, power supply circuit provides operating voltage. The utility model discloses can adapt to the power supply voltage scope of broad, have current -limiting protect function and frequency band, the range is adjustable, has eliminated low frequency component and the influences of highs pairing vibration measuring such as direct current, has improved measurement accuracy, reduces the requirement to data acquisition facility.

Description

A kind of capacitance-type triaxial integration vibration transducer

Technical field

The utility model relates to a kind of capacitance-type triaxial integration vibration transducer, belongs to vibration survey field.

Background technology

Since the nineties in last century, having had built-in circuit, the integrated vibration transducer application exported with low-resistance form is more and more extensive, such as the IEPE vibration transducer of BK company of Denmark, the ICP vibration transducer of PCB company of the U.S.. The sensor built-in circuit mainly realizes impedance matching and signal conditioning, and filtering free circuit, the frequency response of sensor depends primarily on sensor.

The vibration transducer frequency response slightly difference of different principle, integration vibration transducer divides from measuring principle and mainly contains piezoelectric type, condenser type and pressure resistance type. The frequency response of piezoelectric type integration vibration transducer is generally 0.1Hz to tens kHz or tens kHz, such sensor frequency band is wider, in order to avoid occurring mixed folding in signal acquisition process, affects measuring accuracy, therefore signal sampling frequency requirement is higher, it is bigger that it stores data capacity. Condenser type and pressure resistance type integration vibration transducer frequency response are generally 0Hz to a few kHz, such sensor has DC response, when measurement environment exists the low frequency signals such as overload, easily cause vibration signal limiter, particularly for the sensor of little range, its sensor even may occur saturated, affects vibration survey precision. Such as at space industry, rocket launching or aircraft flight process both existed axially (direction of namely flying) low frequency acceleration signal (namely transshipping) and also there is the higher vibration signal of frequency, and vibrate signal and safety monitoring, aerodynamic arrangement are analyzed significant, therefore must peeling off low frequency overload signal to the impact of vibration survey, this just needs can the vibration transducer of the low frequency composition signal such as isolated DC. On the other hand, the vibration measuring parameters of rocket and aircraft need to pass ground back, and by the restriction of Signal transmissions bandwidth, signal sampling frequency is not high, therefore must limiting by frequency measurement vibration transducer, otherwise there will be mixed folded, affect measuring accuracy.

Practical novel content

The technical problem that the utility model solves is: overcome the deficiencies in the prior art; provide a kind of capacitance-type triaxial integration vibration transducer; wider power supply voltage range can be adapted to; have current limliting protection function and frequency band, range is adjustable; eliminate the low frequency components such as direct current and high frequency component to the impact of vibration survey; improve measuring accuracy, reduce the requirement to data acquisition equipment.

The technical scheme that the utility model adopts is: a kind of capacitance-type triaxial integration vibration transducer, comprising: capacitance silicon micro-acceleration gauge, filtering circuit, every straight and bias amplifier, power source circuit; Vibration signal is converted into voltage signal and exports by silicon capacitance jerkmeter, and its output terminal is connected with the input terminus of filtering circuit; Filtering circuit adopts eight rank low pass oblong switches capacitor filter and RC circuit, and the voltage signal of silicon capacitance accelerometer input is carried out filtering, and filtering circuit exports and is connected with every straight and bias amplifier input; Every straight and bias amplifier filtering DC voltage component, obtain in the voltage range of 0V��5V and export; Power source circuit and capacitance silicon micro-acceleration gauge, filtering circuit, it is connected every straight and bias amplifier simultaneously and provides work to power.

Described filtering circuit comprises resistance R1, electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, eight rank low pass oblong switches capacitor filter N1, silicon capacitance jerkmeter output terminal contact resistance R1, ground connection after resistance R1 and electric capacity C2 series connection, resistance R1 and electric capacity C2 connects the input port IN that public termination enters eight rank low pass oblong switches capacitor filter N1, the power supply port VDD of eight rank low pass oblong switches capacitor filter N1 meets power supply VCC after being connected with shutoff control signal port SHDN and is connected with electric capacity C1, electric capacity C1 the other end ground connection, the public port COM of eight rank low pass oblong switches capacitor filter N1 and biased adjustment input terminus OS connects, public end after connection is connected rear ground connection with electric capacity C3, electric capacity C4 connect with input end of clock mouth CLK after ground connection, the grounding ports GND ground connection of eight rank low pass oblong switches capacitor filter N1.

Described comprise resistance R2, resistance R3, resistance R4, resistance R5, resistance R6, resistance R7, operational amplifier N2A, operational amplifier N2B, electric capacity C5, electric capacity C6, electric capacity C7 every straight and bias amplifier; Resistance R2 mono-termination power supply VCC, the other end connect with resistance R3 after ground connection, electric capacity C5 is connected in parallel on the two ends of resistance R3, resistance R2 is connected with the in-phase input end of operational amplifier N2A with the tie point of resistance R3, the power supply termination power supply VCC of operational amplifier N2A, signal ground end ground connection, inverting input is connected with output terminal; The output terminal of the one termination operational amplifier N2A of resistance R4, the in-phase input end of another termination operational amplifier N2B, electric capacity C6 mono-termination wave filter exports, the other end connecting resistance R5, the resistance R5 the other end is connected with the inverting input of operational amplifier N2B, after resistance R6 is in parallel with electric capacity C7, the inverting input of one termination operational amplifier N2B, the output terminal of another termination operational amplifier N2B, the output terminal of resistance R7 mono-termination operational amplifier N2B, the other end is the output of sensor.

Described power source circuit comprises resistance R8, electric capacity C7, electric capacity C8, electric capacity C9, electric capacity C10, a reference source N3; The one termination power supply of resistance R8, the other end is connected with dormancy end with the input terminus VS of a reference source N3, one end ground connection after electric capacity C7 and electric capacity C8 parallel connection, the input terminus VS of another termination a reference source N3 and dormancy end, after electric capacity C9 and electric capacity C10 parallel connection, the output terminal of one termination power supply VCC and a reference source N3, the signal ground end of another termination a reference source N3 and ground connection.

The utility model advantage compared with prior art is:

(1) the utility model by having isolated the low frequency signal of below 1Hz every straight and bias amplifier, high-frequency signal is limited by filtering circuit, thus eliminate the low frequency components such as direct current and high frequency component to the impact of vibration survey, eliminate the signals such as overload to the impact of vibration survey, it is to increase responding range and measuring accuracy.

(2) the utility model can according to actual measurement demand, adjust capacitance silicon micro-acceleration gauge range and realize any range every straight and bias amplifier gain and arrange, compared with relatively needing to change multiple resistance, capacitance with conventional filter adjustment bandwidth, by adjusting a capacitance, sensor filter bandwidth can be set, reduce data sampling frequency, it is convenient to record and the collection of signal.

(3) the utility model forms power source circuit jointly by current limliting resistance, filter capacitor, a reference source; there is current limliting protection function; prevent owing to sensor faults itself causes the damage of power supply; the utility model has wider service voltage simultaneously, it is possible to normal operation under the service voltage of 9V��18V.

Accompanying drawing explanation

Fig. 1 is the utility model functional block diagram;

Fig. 2 is the utility model filtering circuit schematic diagram;

Fig. 3 is that the utility model is every straight and bias amplifier schematic diagram;

Fig. 4 is the utility model power circuit principle figure.

Embodiment

As shown in Figure 1, a kind of capacitance-type triaxial integration vibration transducer, comprise capacitance silicon micro-acceleration gauge, filtering circuit, every straight and bias amplifier, power source circuit. Silicon capacitance jerkmeter has frequency band width, the advantage of good temp characteristic. When there being vibration signal, silicon capacitance jerkmeter exports the voltage signal with vibration level equity, and its output terminal is connected with the input terminus of filtering circuit. The eight rank low pass oblong switches capacitor filters that filtering circuit adopts, have the interior roughness of band preferably and attenuation outside a channel, and by regulating electric capacity just can complete frequency band adjustment. Wave filter exports and is connected with every straight and bias amplifier input, after the DC voltage component of filtering front stage circuits, is nursed one's health by signal in the voltage range of 0V��5V, and provides direct current (DC) bias. Power source circuit is capacitance silicon micro-acceleration gauge, filtering circuit, powers every straight and bias amplifier.

Capacitance silicon micro-acceleration is counted based on silicon capacitance principle, adopt the acceleration measurement system of micromachining technology, inside is integrated with signal conditioning circuit, its useful range is divided into 2g, 10g, 30g, 50g, 100g, 200g, corresponding sensitivity is respectively 1000mV/g, 200mV/g, 66.6mV/g, 40mV/g, 20mV/g, 10mV/g, can select the jerkmeter of corresponding useful range according to actual measurement demand.

As shown in Figure 2, filtering circuit is made up of RC circuit and eight rank low pass oblong switches capacitor filter N1. Ground connection after silicon capacitance jerkmeter output terminal contact resistance R1, resistance R1 and electric capacity C2 series connection, resistance R1 and electric capacity C2 connects the input port IN (2 pin) that public termination enters eight rank low pass oblong switches capacitor filter N1; The power supply port VDD (4 pin) of eight rank low pass oblong switches capacitor filter N1 and shutoff control signal port SHDN (7 pin) meet power supply VCC after connecting, with the power supply port VDD (4 pin) of eight rank low pass oblong switches capacitor filter N1 and the public end connection of connection turning off control signal port SHDN (7 pin) after electric capacity C1 ground connection; Public port COM (1 pin) and biased adjustment input terminus OS (6 pin) of eight rank low pass oblong switches capacitor filter N1 connect, and the public end after connection is connected rear ground connection with electric capacity C3. Eight rank low pass oblong switches capacitor filter N1 attenuation outside a channels are greater than 50dB, and the ratio of this wave filter internal clock frequencies and limiting frequency is 100:1, and wave filter is operated in inner clock pattern. Electric capacity C4 connect with the input end of clock mouth CLK (8 pin) of eight rank low pass oblong switches capacitor filter N1 after ground connection, by adjust electric capacity C4 capacitance change filtering limiting frequency, grounding ports GND ground connection. Wave filter limiting frequency fc calculates as follows:

$fc=\frac{380}{c_4}$

Wherein, fc is wave filter limiting frequency, and unit is kHz, c₄For capacitance, unit is pf.

As shown in Figure 3, stopping condenser, bias voltage generating circuit, output amplifier is comprised every straight and bias amplifier. Electric capacity C5, resistance R2, resistance R3 and operational amplifier N2A form bias voltage generating circuit, and biased voltage is obtained by resistance R2 and resistance R3 dividing potential drop. Resistance R4, resistance R5, resistance R6, resistance R7, electric capacity C7, operational amplifier N2B form output amplifier, and this circuit is 1 for the gain of direct current signal, and the gain of exchange signal is-R3/R5. The equivalent output impedance of whole circuit depends on R7. Resistance R2 mono-termination power supply VCC, the other end connect with resistance R3 after ground connection, electric capacity C5 is connected in parallel on the two ends of resistance R3. Resistance R2 is connected with the in-phase input end (3 pin) of operational amplifier N2A with the tie point of resistance R3. The power supply end (8 pin) of operational amplifier N2A meets power supply VCC, signal ground end (4 pin) ground connection, and inverting input (2 pin) is connected with output terminal (1 pin). The output terminal (1 pin) of the one termination operational amplifier N2A of resistance R4, the in-phase input end (5 pin) of another termination operational amplifier N2B; Electric capacity C6 is stopping condenser, the low-frequency level component of filtering front stage circuits, its termination wave filter exports, the other end connecting resistance R5, the resistance R5 the other end is connected with the inverting input (6 pin) of operational amplifier N2B, after resistance R6 is in parallel with electric capacity C7, the inverting input (6 pin) of one termination operational amplifier N2B, the output terminal (7 pin) of another termination operational amplifier N2B, the output terminal (7 pin) of resistance R7 mono-termination operational amplifier N2B, the other end is the output of sensor.

As shown in Figure 4, power source circuit is made up of a reference source N3, filter capacitor C7, electric capacity C8, electric capacity C9, electric capacity C10, current limliting resistance R8. The 5V of N3 to be load current be 30mA exports a reference source, and R8 is current limliting resistance, protection power supply when main function is to prevent circuit from signal ground occurring short circuit or low-resistance situation. The one termination power supply of resistance R8, the other end is connected with dormancy end SLEEP (3 pin) with the input terminus VS (2 pin) of a reference source N3, one end ground connection after electric capacity C7 and electric capacity C8 parallel connection, the input terminus VS (2 pin) and dormancy end SLEEP (3 pin) of another termination a reference source N3, after electric capacity C9 and electric capacity C10 parallel connection, the output terminal OUTPUT (6 pin) of one termination power supply VCC and a reference source N3, the signal ground end GND (4 pin) of another termination a reference source N3, the common end grounding of the signal ground end GND of electric capacity C9, electric capacity C10 and a reference source N3.

The content that the utility model specification sheets is not described in detail belongs to the known technology of those skilled in the art.

Claims (4)

1. capacitance-type triaxial integration vibration transducer, it is characterised in that, comprising: capacitance silicon micro-acceleration gauge, filtering circuit, every straight and bias amplifier, power source circuit; Vibration signal is converted into voltage signal and exports by silicon capacitance jerkmeter, and its output terminal is connected with the input terminus of filtering circuit; Filtering circuit adopts eight rank low pass oblong switches capacitor filter and RC circuit, and the voltage signal of silicon capacitance accelerometer input is carried out filtering, and filtering circuit exports and is connected with every straight and bias amplifier input; Every straight and bias amplifier filtering DC voltage component, obtain the voltage signal of 0V��5V and export; Power source circuit and capacitance silicon micro-acceleration gauge, filtering circuit, it is connected every straight and bias amplifier simultaneously and operating voltage is provided.

2. a kind of capacitance-type triaxial integration vibration transducer according to claim 1, it is characterised in that: described filtering circuit comprises resistance R1, electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, eight rank low pass oblong switches capacitor filter N1, silicon capacitance jerkmeter output terminal contact resistance R1, ground connection after resistance R1 and electric capacity C2 series connection, resistance R1 and electric capacity C2 connects the input port IN that public termination enters eight rank low pass oblong switches capacitor filter N1, the power supply port VDD of eight rank low pass oblong switches capacitor filter N1 meets power supply VCC after being connected with shutoff control signal port SHDN and is connected with electric capacity C1, electric capacity C1 the other end ground connection, the public port COM of eight rank low pass oblong switches capacitor filter N1 and biased adjustment input terminus OS connects, public end after connection is connected rear ground connection with electric capacity C3, electric capacity C4 connect with input end of clock mouth CLK after ground connection, the grounding ports GND ground connection of eight rank low pass oblong switches capacitor filter N1.

3. a kind of capacitance-type triaxial integration vibration transducer according to claim 1 and 2, it is characterised in that: described comprise resistance R2, resistance R3, resistance R4, resistance R5, resistance R6, resistance R7, operational amplifier N2A, operational amplifier N2B, electric capacity C5, electric capacity C6, electric capacity C7 every straight and bias amplifier; Resistance R2 mono-termination power supply VCC, the other end connect with resistance R3 after ground connection, electric capacity C5 is connected in parallel on the two ends of resistance R3, resistance R2 is connected with the in-phase input end of operational amplifier N2A with the tie point of resistance R3, the power supply termination power supply VCC of operational amplifier N2A, signal ground end ground connection, inverting input is connected with output terminal; The output terminal of the one termination operational amplifier N2A of resistance R4, the in-phase input end of another termination operational amplifier N2B, electric capacity C6 mono-termination filtering circuit exports, the other end connecting resistance R5, the resistance R5 the other end is connected with the inverting input of operational amplifier N2B, after resistance R6 is in parallel with electric capacity C7, the inverting input of one termination operational amplifier N2B, the output terminal of another termination operational amplifier N2B, the output terminal of resistance R7 mono-termination operational amplifier N2B, the other end is the output of sensor.

4. a kind of capacitance-type triaxial integration vibration transducer according to claim 3, it is characterised in that: described power source circuit comprises resistance R8, electric capacity C7, electric capacity C8, electric capacity C9, electric capacity C10, a reference source N3; The one termination power supply of resistance R8, the other end is connected with dormancy end SLEEP with the input terminus VS of a reference source N3, one end ground connection after electric capacity C7 and electric capacity C8 parallel connection, the input terminus VS and dormancy end SLEEP of another termination a reference source N3, after electric capacity C9 and electric capacity C10 parallel connection, the signal ground end GND of the output terminal OUTPUT of one termination power supply VCC and a reference source N3, another termination a reference source N3, the common end grounding of the signal ground end GND of electric capacity C9, electric capacity C10 and a reference source N3.