CN205620054U - Pressure becomes power transmission way - Google Patents

Abstract

The utility model discloses a pressure becomes power transmission way. 4 20mA current output is the industrial remote output signal that the high efficiency is reliable, does pressure change 4 20mA's module circuit increases day by day. The utility model discloses a constant current source generating circuit provides constant current source for diffusion silicon pressure sensor, and diffusion silicon pressure sensor converts pressure signal into the voltage difference signal, accurate differential voltage amplifier circuit is used for enlargeing the voltage difference signal that diffusion silicon pressure sensor produced to does to enlarge the signal of handling well through the sampling resistor turn into 4 the 20mA signal carries out remote output. The utility model discloses upward the electricity can obtain accurate electrorheological and send numerical value, and reading data time interval tripping power scene is far away, has prolonged safe distance effectively.

Description

Pressure inverting circuit

Technical field

This utility model belongs to electronic technology field, is specifically related to a kind of pressure inverting circuit.

Background technology

Along with the continuous progress of society's industry, people carry day by day for the requirement of measurements various in daily life High.Owing to pressure measxurement is likely to be of certain danger, to pressure signal long-distance transmissions and monitor Require also to become increasingly conspicuous, and the output of 4-20mA electric current is the industrial long-range output letter of a kind of high efficient and reliable Number, the most day by day increase so turning the modular circuit of 4-20mA for pressure.

Some special measuring pressure instrument and meter heavinesses are unfavorable for carrying, and most price is much more expensive, right The most convenient in the use of industry spot.

Summary of the invention

The purpose of this utility model is for the deficiencies in the prior art, it is provided that a kind of for diffused-silicon pressure The pressure inverting circuit that sensor signal measures.

This utility model includes that constant-current source generation circuit, diffusion silicon pressure sensor, precision differential voltage are put Big circuit and power supply circuits；Described constant-current source generation circuit provides constant electricity to diffusion silicon pressure sensor Stream, pressure signal is converted to voltage differential signal by diffusion silicon pressure sensor；Described precision differential voltage Amplifying circuit is used for amplifying the voltage differential signal that diffusion silicon pressure sensor produces, and will by sampling resistor The signal that processing and amplifying is good is converted into 4-20mA signal and remotely exports.

Power supply circuits include that model is Voltage stabilizing module A1 and A2 of LM317；The 3 of Voltage stabilizing module A2 Pin connects the negative pole of diode D1, one end of 2 pin connecting resistance R2；Another termination voltage stabilizing of resistance R2 1 pin of modules A 2 output voltage V2 are that precision differential voltage amplifier circuit is powered；Diode D1 Positive pole connect one end of electric capacity C0 and CK0 and input supply voltage VCC；Another termination of electric capacity CK0 One end of electric capacity CK1, one end of another termination capacitor C1 of electric capacity CK1 and C0 also connects externally； 3 pins of another termination Voltage stabilizing module A1 of electric capacity C1；The 2 pin connecting resistance R1 of Voltage stabilizing module A1 One end, the other end of 1 pin connecting resistance R1 and the negative pole of diode D2 output voltage V1 are constant current Source occurs circuit and precision differential voltage amplifier circuit to power；The positive pole of diode D2 connects internally.

Described diffusion silicon pressure sensor uses Hangzhou meter Ke sensor company limited to produce MIK-P300E pressure transducer.

Constant-current source generation circuit includes amplifier A3B, diode D3, diode D4 and resistance R8；Put The normal phase input end of big device A3B connects positive pole and the negative pole of diode D4 of diode D3；Amplifier A3B Inverting input be connected with one end of resistance R8 and connect the negative voltage input of diffusion silicon pressure sensor； The positive voltage input of the output termination diffusion silicon pressure sensor of amplifier A3B；Another of resistance R8 The positive pole of end and diode D4 all connects internally；The negative pole of diode D3 connects the output voltage of power supply circuits V1。

Precision differential voltage amplifier circuit includes amplifier A3A, A4A, A4B and audion A5；Amplify The normal phase input end of device A4A meets the voltage differential signal negative terminal S that diffusion silicon pressure sensor produces_-And electric capacity One end of C2, the output voltage V1 of positive supply voltage termination power supply circuits, negative supply voltage terminates internally； The normal phase input end of amplifier A4B meets the voltage differential signal anode S that diffusion silicon pressure sensor produces₊And electricity Hold the other end of C2；One end of outfan connecting resistance R10 and R11 of amplifier A4A, anti-phase input The sliding end of termination gain resistor WS and the other end of resistance R10；One of gain resistor WS fixes One end of terminating resistor R9, the inverting input of another termination amplifier A4B of resistance R9 and resistance One end of R13, one end of the outfan connecting resistance R14 of amplifier A4B and the other end of resistance R13； One end of other end connecting resistance R15 of resistance R14, one end of resistance R18, one end of electric capacity C4 and The normal phase input end of amplifier A3A；One end of other end connecting resistance R12 of resistance R11, resistance R17 One end, one end of electric capacity C3 and the inverting input of amplifier A3A；The just power supply of amplifier A3A The output voltage V1 of voltage termination power supply circuits, negative supply voltage terminates internally；Amplifier A3A's is defeated Go out one end of terminating resistor R16, the base stage of another termination audion A5 of resistance R16；Audion A5 One end of emitter stage connecting resistance R20, the other end of resistance R12, the other end of electric capacity C3 in connecing Ground, portion；One end of the colelctor electrode connecting resistance R19 of audion A5, another termination power supply electricity of resistance R19 The output voltage V2 on road；The other end connecting resistance R15 of resistance R20 and the other end of electric capacity C4 outside connecing Ground, portion；One end of other end connecting resistance R5 and R6 of resistance R17；Another termination constant current of resistance R5 There is the positive pole of diode D3 in circuit in source；Another termination of resistance R6 is internally；Resistance R18's is another The sliding end of one termination zero-regulator resistor WZ；One end of one fixing terminating resistor R3 of zero-regulator resistor WZ, One end of another fixing terminating resistor R4；Two poles in another termination constant-current source generation circuit of resistance R3 The positive pole of pipe D3；Another termination of resistance R4 is internally.

The beneficial effects of the utility model:

This utility model is simple to operate, powers on and can obtain electric current pick-up numerical value accurately, when reading data Distance pressure scene farther out, effectively extends safe distance, can preferably ensure the people of staff Body safety.

Accompanying drawing explanation

Fig. 1 is system block diagram of the present utility model；

Fig. 2 is the circuit diagram of constant-current source generation circuit in this utility model；

Fig. 3 is the circuit diagram of precision differential voltage amplifier circuit in this utility model；

Fig. 4 is the circuit diagram of power supply circuits in this utility model.

Detailed description of the invention

The utility model is described in further detail below in conjunction with the accompanying drawings.

As it is shown in figure 1, pressure inverting circuit includes constant-current source generation circuit 101, diffusion silicon pressure sensor 102, precision differential voltage amplifier circuit 103 and power supply circuits 104；Power supply circuits 104 are sent out to constant-current source Raw circuit 101 and precision differential voltage amplifier circuit 103 are powered；Constant-current source generation circuit 101 gives diffusion Silicon pressure sensor 102 provides constant current, diffusion silicon pressure sensor 102 to be converted to by pressure signal Voltage differential signal.Precision differential voltage amplifier circuit 103 is for amplifying what diffusion silicon pressure sensor produced Voltage differential signal, is amplified to vor signal by faint millivolt signal so that the electric current output of rear class is more stable, And by sampling resistor, the signal that processing and amplifying is good is converted into 4-20mA signal and remotely exports.

Diffusion silicon pressure sensor uses the MIK-P300E that Hangzhou meter Ke sensor company limited produces, energy Enough measure the force value (corresponding voltage difference scope is 0～60mV) of 0～2Mpa, measure temperature at-10 DEG C～ 80℃.Diffusion silicon pressure sensor is to form 4 with ion implanting and laser modification method on silicon elastic film sheet The diffusion resistance that individual resistance is equal, forms a wheatstone bridge.At electric bridge a, b two ends during constant current-supplying Forming a potential difference, when pressure is the biggest, this potential difference is the biggest, and this potential difference is carried out precision 4-20mA output is carried out after amplifying.

Below in conjunction with Fig. 2 and Fig. 3 explanation by diffusion silicon pressure sensor according to potential differentiation measuring principle Measure pressure the method exporting 4-20mA electric current.Wheatstone bridge when potential differentiation is to utilize pressure effect An arm change in resistance, and in the case of the electric current that flows through electric bridge is immovable, form one at two outfans The potential difference being directly proportional to the pressure.

In order to obtain potential difference firstly the need of a constant current value I₁.As in figure 2 it is shown, constant-current source occurs Circuit 101 includes amplifier A3B；Diode D₄Produce a constant voltage reference V_REF, V₊Connect with V- The current input terminal of wheatstone bridge, 5 feet of amplifier A3B and the voltage of 6 feet are identical again, can obtain Arrive

$I_1=\frac{V_{REF}}{R_8}---\left(1\right)$

Wherein, R₈For the resistance of resistance R8, V_REFMagnitude of voltage for REF end.

As it is shown on figure 3, when there being pressure to be applied to diffusion silicon pressure sensor, diffusion silicon pressure sensor Form a potential difference to export to S through precision differential voltage amplifier circuit 103₊And S_-Two ends, can obtain At supply voltage end and externally electric current output formula between GND36

$I_2=\frac{\left(\frac{200+R_G}{R_G}\right)(V_{S+}-V_{S-})+(V_2-V_1)}{R_{20}}---\left(2\right)$

Wherein, V₁Dividing potential drop for resistance R5 and R6；V₂For resistance R3, zero-regulator resistor WZ and R4 Dividing potential drop；V_S+For S₊Terminal voltage, V_S-For S_-Terminal voltage；R_GFor gain resistor WS and the resistance of resistance R9 Sum；GND36 is externally, and GND is internally.

When the potential difference that diffusion silicon pressure sensor is formed is zero, S₊With S_-The potential difference of end is substantially equal to Zero, therefore zero point and consequent V₂-V₁Relevant, work as V₂-V₁When determining, only need to determine that the value of resistance R20 is with regard to energy Adjust offset output.Have error due to resistance in a practical situation, therefore add zero-regulator resistor WZ, logical Cross WZ regulation and cause error because of resistance and circuit, revise zero point error.

When pressure is 2MPa, S₊With S_-The potential difference of end is about 60mV, and after zeroing, full scale is only WithRelevant.By regulation gain resistor WS, by current value adjustment during Full-span output it is 20mA.The resistance of gain resistor must be chosen properly, is otherwise likely to occur full scale current and does not reaches or super Cross range and adjust the phenomenon do not returned.

Fig. 4 is the power supply circuits of whole system, and wherein VCC Yu GND36 is the input both positive and negative polarity of power supply, V2 produces 4-20mA for precision differential voltage amplifier circuit and provides a High Voltage Power Supply, and V1 is constant-current source Circuit and A3A, A3B, A4A, A4B operational amplifier is occurred to power.

Claims (4)

1. pressure inverting circuit, including constant-current source generation circuit, diffusion silicon pressure sensor, precision differential electricity Pressure amplifying circuit and power supply circuits, it is characterised in that: described constant-current source generation circuit senses to diffused-silicon pressure Device provides constant current, and pressure signal is converted to voltage differential signal by diffusion silicon pressure sensor；Described precision Differential voltage amplifying circuit is for amplifying the voltage differential signal that diffusion silicon pressure sensor produces and electric by sampling The signal that processing and amplifying is good is converted into 4-20mA signal and remotely exports by resistance；

Power supply circuits include that model is Voltage stabilizing module A1 and A2 of LM317；The 3 of Voltage stabilizing module A2 are drawn Foot connects the negative pole of diode D1, one end of 2 pin connecting resistance R2；Another termination Voltage stabilizing module of resistance R2 1 pin of A2 output voltage V2 are that precision differential voltage amplifier circuit is powered；The positive pole of diode D1 connects One end of electric capacity C0 and CK0 also inputs supply voltage VCC；Another termination capacitor CK1 of electric capacity CK0 One end, one end of another termination capacitor C1 of electric capacity CK1 and C0 also connects externally；Electric capacity C1's is another 3 pins of one termination Voltage stabilizing module A1；One end of the 2 pin connecting resistance R1 of Voltage stabilizing module A1,1 pin The other end of connecting resistance R1 and the negative pole of diode D2 output voltage V1 are constant-current source generation circuit and precision Differential voltage amplifying circuit is powered；The positive pole of diode D2 connects internally.

Pressure inverting circuit the most according to claim 1, it is characterised in that: described diffused-silicon pressure Sensor uses the MIK-P300E pressure transducer that Hangzhou meter Ke sensor company limited produces.

Pressure inverting circuit the most according to claim 1, it is characterised in that: constant-current source generation circuit bag Include amplifier A3B, diode D3, diode D4 and resistance R8；The normal phase input end of amplifier A3B connects The positive pole of diode D3 and the negative pole of diode D4；The inverting input of amplifier A3B is with resistance R8's One end connects and connects the negative voltage input of diffusion silicon pressure sensor；The output termination diffusion of amplifier A3B The positive voltage input of silicon pressure sensor；The other end of resistance R8 and the positive pole of diode D4 all connect inside Ground；The negative pole of diode D3 meets the output voltage V1 of power supply circuits.

Pressure inverting circuit the most according to claim 3, it is characterised in that: precision differential voltage amplification Circuit includes amplifier A3A, A4A, A4B and audion A5；The normal phase input end of amplifier A4A connects expansion Dissipating voltage differential signal negative terminal S-and one end of electric capacity C2 that silicon pressure sensor produces, positive supply voltage termination supplies The output voltage V1 of electricity circuit, negative supply voltage terminates internally；The normal phase input end of amplifier A4B connects expansion Dissipate the voltage differential signal anode S that silicon pressure sensor produces₊And the other end of electric capacity C2；Amplifier A4A's is defeated Go out one end of terminating resistor R10 and R11, the sliding end of anti-phase input termination gain resistor WS and resistance R10 The other end；One end of one fixing terminating resistor R9 of gain resistor WS, another termination of resistance R9 The inverting input of amplifier A4B and one end of resistance R13, the outfan connecting resistance R14 of amplifier A4B One end and the other end of resistance R13；One end of other end connecting resistance R15 of resistance R14, resistance R18 One end, one end of electric capacity C4 and the normal phase input end of amplifier A3A；Another termination electricity of resistance R11 Resistance one end of R12, one end of resistance R17, one end of electric capacity C3 and the inverting input of amplifier A3A； The output voltage V1 of the positive supply voltage termination power supply circuits of amplifier A3A, negative supply voltage terminates internally； One end of the outfan connecting resistance R16 of amplifier A3A, the base of another termination audion A5 of resistance R16 Pole；One end of emitter stage connecting resistance R20 of audion A5, the other end of resistance R12, electric capacity C3 another One end also connects internally；One end of the colelctor electrode connecting resistance R19 of audion A5, another termination of resistance R19 The output voltage V2 of power supply circuits；The other end of the other end connecting resistance R15 and electric capacity C4 of resistance R20 is also Connect externally；One end of other end connecting resistance R5 and R6 of resistance R17；Another termination constant current of resistance R5 There is the positive pole of diode D3 in circuit in source；Another termination of resistance R6 is internally；Another of resistance R18 The sliding end of termination zero-regulator resistor WZ；One end of one fixing terminating resistor R3 of zero-regulator resistor WZ, separately One end of one fixing terminating resistor R4；Diode D3 in another termination constant-current source generation circuit of resistance R3 Positive pole；Another termination of resistance R4 is internally.