CN201435721Y - Fluxgate sensor excitation circuit with inverter and inverting differentiator - Google Patents

Abstract

The utility model discloses a fluxgate sensor excitation circuit with an inverter and an inverting differentiator. The utility model is characterized in that: a resistor R1, a capacitor C1 and an operational amplifier A1 are connected to an inverting integrator; a resistor R2, a resistor R8, a capacitor C2 and an operational amplifier A2 are connected to the inverting differentiator; a resistor R3, a resistor R4, an adjustable resistor W1 and an operational amplifier A3 are connected to an adder; the input end of the integrator is connected with the input square wave signal end, and the inputsquare wave signal end is connected with the input end of the inverting differentiator through an inverter N1; the output of the integrator is connected with one input end R3 of the adder; the outputof the differentiator is connected with the other input end W1 of the adder; and a capacitor Cp is connected between the output end of the adder and the input end of the fluxgate. The circuit can be used for generating the excitation signal of the fluxgate and reducing the residual magnesium error of the fluxgate without the operation of an excitation circuit in the toning state.

Description

The exciting circuit of flux gate sensor that contains inverter and anti-phase differentiator

Technical field

The utility model relates to a kind of exciting circuit, particularly contains the exciting circuit of flux gate sensor of inverter and anti-phase differentiator.

Background technology

Remanence error is that Magnetic Sensor is subjected to changing the additive error of generation because of the remanent magnetism of magnetic material than after the high-intensity magnetic field interference.Compare with other Magnetic Sensors, the remanence error of fluxgate sensor is less, but must further reduce remanence error in the high request occasion.Improve exciting current and can effectively reduce the remanence error of fluxgate sensor, but also caused the big problem of power consumption.

Document 1 " Pulse Excitation of Micro-Fluxgate Sensors; IEEE TRANSACTIONS ON MAGNETICS; VOL.37; NO.4, JULY 2001 1988-2000 " discloses a kind of employing burst pulse motivational techniques, can obtain enough exciting current amplitudes under the little situation of power consumption, thereby remanence error is effectively fallen, but this method makes the sensitivity of fluxgate reduce under the same conditions, and high order harmonic component is more in the output signal, brings difficulty to signal extraction.

With reference to Fig. 5, document 2 " Switching-mode fluxgate; TRANSDUCERS ' 03.12th International Conference onSolid-State Sensors; Actuators and Microsystems, 2003, Vol.2; pp1283-1286 " and document 3 " Excitationefficiency of fluxgate sensors; Sensors and Actuators A 129,2006, pp75-79. " disclose a kind of tuning method of end that encourages and have reduced the fluxgate remanence error.Its pumping signal is the square-wave signal that produces with switching circuit, tuning capacity Cr of series connection between the excitation input 2 of signal output part 1 and fluxgate 3.The characteristic of utilizing fluxgate excitation coil inductance to reduce behind core sataration by regulating the fluxgate excitation coil resonance after series capacitance Cr makes itself and core sataration, obtains a kind of sine-wave excitation current signal that has burst pulse at the peak value place.This method through suitable tuning after, after the experience magnetic field intensity is the impact of 5mT, but the remanent magnetism error reaches 1nT, consumed power is 50mW.The numerical value that this method must carefully be regulated series capacitance makes it produce resonance at driving frequency place and excitation coil inductance.When ambient temperature changed, the variation of shunt capacitance numerical value and excitation coil variation inductance might depart from or destroy this resonance condition.In resonance condition, the effective value of peak value of exciting current (being the peak value of spike) and exciting current is regulated very inconvenient.

Summary of the invention

Regulate the deficiency of difficulty in order to overcome prior art resonance, the utility model provides a kind of exciting circuit of flux gate sensor that contains inverter and anti-phase differentiator, adopt electronic circuit respectively square-wave signal to be carried out integration and differential acquisition triangular wave and spike signal, again their addition is obtained a kind of pumping signal of the triangle wave voltage signal of spike as fluxgate that have at the peak value place.Its output waveform guarantees by circuit function, need not regulate resonance, thereby temperature influence is little, and can conveniently regulates exciting current peak value and effective value.

The technical scheme that its technical problem that solves the utility model adopts is: a kind of exciting circuit of flux gate sensor that contains inverter and anti-phase differentiator is characterized in: resistance R ₁, capacitor C ₁And operational amplifier A ₁Connect into inverting integrator, resistance R ₂, resistance R ₈, capacitor C ₂And operational amplifier A ₂Connect into anti-phase differentiator, resistance R ₃, resistance R ₄, adjustable resistance W ₁And operational amplifier A ₃Connect into adder, the integrator input is connected with the square-wave signal end of input, and the square-wave signal end of input is through inverter N ₁Link to each other an input R of the output of integrator and adder with the input of anti-phase differentiator ₃Connect; Another input W of the output of differentiator and adder ₁Connect, be connected capacitor C p between the output of adder and the input of fluxgate.

The beneficial effects of the utility model are: have the pumping signal of the signal of spike as fluxgate owing to adopt the method for integration, differential and addition to be created in triangular wave peak value place.Its output waveform guarantees by circuit function, need not regulate resonance, thereby temperature influence is little, and can conveniently regulates exciting current peak value and effective value.The utility model is after the experience magnetic field intensity is the impact of 10mT, but the remanent magnetism error reaches 0.5nT, and consumed power is 42mW.With the background technology contrast, the utility model is not carrying out under the tuning situation, and disturbing magnetic field has increased one times, and remanence error has reduced half, and power consumption has reduced 8mW.

Below in conjunction with the drawings and specific embodiments the utility model is elaborated.

Description of drawings

Fig. 1 is the circuit diagram that the utility model contains the exciting circuit of flux gate sensor of inverter and anti-phase differentiator.

Fig. 2 is the circuit diagram of background technology.

Among the figure, 1-square-wave signal, 2-fluxgate excitation input, 3-fluxgate, 4-exciting circuit output.

Embodiment

With reference to Fig. 1.(1) resistance R ₁, capacitor C ₁And operational amplifier A ₁Connect into inverting integrator;

(2) resistance R ₂, resistance R ₈, capacitor C ₂And operational amplifier A ₂Connect into anti-phase differentiator;

(3) resistance R ₃, resistance R ₄, adjustable resistance W ₁And operational amplifier A ₃Connect into adder, operational amplifier A ₃Have the power drive ability, can export driving voltage and exciting current that the present embodiment circuit produces without distortion;

(4) the integrator input is connected with square-wave signal 1 end of input;

(5) Shu Ru square-wave signal 1 end is through inverter N ₁Link to each other with the input of anti-phase differentiator;

(6) output of integrator and adder input R ₃Connect; Another input W of the output of differentiator and adder ₁Connect;

(7) resistance R ₁, capacitor C ₁, resistance R ₃And resistance R ₄Numerical value by the driving frequency of fluxgate, the peak-to-peak value of the peak-to-peak value of required driving voltage triangular wave part and input square wave is determined.The peak-to-peak value Vp-p and the resistance R of required driving voltage triangular wave part ₁, capacitor C ₁, resistance R ₃And resistance R ₄, driving frequency f and the input square wave peak-to-peak value E between the pass be:

$V_{p-p}=\frac{\mathrm{<figure-callout\; id="4"\; label="E"\; filenames="Y2009200338730006H1.png"\; state="\{\{state\}\}">E</figure-callout>}}{4}\&CenterDot;\frac{R_4}{{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="Y2009200338730006H1.png,Y2009200338730006H2.png"\; state="\{\{state\}\}">R</figure-callout>}}_3}\&CenterDot;\frac{1}{R_1{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="Y2009200338730006H1.png,Y2009200338730006H2.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}\&CenterDot;\frac{1}{f}$

When driving frequency is 3kHz, the peak-to-peak value of input square wave is 5V, when the peak-to-peak value Vp-p of required driving voltage triangular wave part is 1.25V, and resistance R ₁Be 10k Ω, capacitor C ₁Be 33nF, resistance R ₃And resistance R ₄Be 10k Ω.Resistance R ₁, capacitor C ₁, resistance R ₃And resistance R ₄Numerical value also can be other combinations of satisfying above-mentioned relation;

(8) driving frequency f is determined by the requirement of employed fluxgate, and the peak-to-peak value Vp-p of driving voltage triangular wave part is greater than the minimum driving voltage peak-to-peak value that makes the fluxgate core sataration.Driving frequency f is 3kHz in the present embodiment, and the peak-to-peak value Vp-p of driving voltage triangular wave part is 1.25V;

(9) timeconstant of integrator ₁(resistance R ₁And capacitor C ₁Product) greater than the timeconstant of differentiator ₂(resistance R ₂And capacitor C ₂Product), according to width and the amplitude requirement to spike, τ ₁Be τ ₂2 to 200 times; In the present embodiment, R ₁Be 10k Ω, capacitor C ₁During for 33nF, R ₂Be 5k Ω, resistance R ₈Be 5k Ω, capacitor C ₂Be 470pF;

(10) variable resistor W ₁Variable range be 0 to resistance R ₄10 times.

(11) be connected capacitor C p between the input 2 of the output 4 of adder and fluxgate 3, its numerical value is greater than 10uF, and to hold the value of Cp be 100uF in power taking in the present embodiment.

The method of present embodiment employing integration, differential and addition is created in triangular wave peak value place and has the pumping signal of the signal of spike as fluxgate.With the background technology contrast, present embodiment is not carrying out under the tuning situation, and disturbing magnetic field has increased one times, and remanence error has reduced half, and power consumption has reduced 8mW.

Claims (1)

1, a kind of exciting circuit of flux gate sensor that contains inverter and anti-phase differentiator is characterized in that: resistance R ₁, capacitor C ₁And operational amplifier A ₁Connect into inverting integrator, resistance R ₂, resistance R ₈, capacitor C ₂And operational amplifier A ₂Connect into anti-phase differentiator, resistance R ₃, resistance R ₄, adjustable resistance W ₁And operational amplifier A ₃Connect into adder, the integrator input is connected with the square-wave signal end of input, and the square-wave signal end of input is through inverter N ₁Link to each other an input R of the output of integrator and adder with the input of anti-phase differentiator ₃Connect; Another input W of the output of differentiator and adder ₁Connect, be connected capacitor C p between the output of adder and the input of fluxgate.

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