CN207380223U - A kind of cascade coupling RTD fluxgates Self-excitation Detection circuit - Google Patents
A kind of cascade coupling RTD fluxgates Self-excitation Detection circuit Download PDFInfo
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- CN207380223U CN207380223U CN201721047146.7U CN201721047146U CN207380223U CN 207380223 U CN207380223 U CN 207380223U CN 201721047146 U CN201721047146 U CN 201721047146U CN 207380223 U CN207380223 U CN 207380223U
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Abstract
The utility model is related to a kind of cascade coupling RTD fluxgates Self-excitation Detection circuit, including:Multigroup RTD fluxgates tandem coupling, every group of RTD magnetic fluxs gate output terminal connection instrument amplifier are amplified the output signal of RTD fluxgates；The signal amplified through instrument amplifier is changed into approximate rectangular wave via integrating circuit；The output terminal of integrating circuit connects the first add circuit, and rectangular wave prevents direct current biasing via the first add circuit adjustment waveform height；The output terminal connection amplifying circuit of first add circuit, via amplifying circuit adjustment output polarity and signal amplitude size, the rectangular wave of amplified signal is removed noise, filter circuit and another group of RTD fluxgate tandems by bandpass filter circuit；RTD fluxgates input terminal connects voltage-current converter circuit, the input terminal of voltage-current converter circuit connects the second add circuit, the input terminal of second add circuit connects the filter circuit of other groups, realizes the interference of multigroup RTD fluxgates tandem coupling removal external signal.
Description
Technical field
The utility model belongs to the measuring circuit field in magnetic field more particularly to a kind of cascade coupling RTD fluxgates self-excitation inspection
Slowdown monitoring circuit.
Background technology
Flux-gate phenomenon is a kind of common magnetic saturation phenomenon.Fluxgate sensor sensing element utilizes periodically supersaturation
The induced electromotive force that the variation of magnetic flux generates is modulated for axial tested magnetic field.With engineering detecting in recent years, electricity
The generally raising of sub- technology and manufacture craft, can particularly measure magnetic field fluxgate sensor have resolving power it is higher,
Range is big, it is small and light-weight the characteristics of, Fluxgate Technique is also generalized among multiple fields rapidly.
Fluxgate sensor mainly carries out magnetic field survey always by the way of traditional using even-order harmonic method for a long time
Amount, output are relatively easy to the influence for receiving odd harmonic noise and some electronic noises, hamper fluxgate sensor
Performance boost.Into 21st century, foreign countries, which begin one's study, carries out the fluxgate sensor of magnetic-field measurement with time difference method, wherein
RTD types fluxgate (time difference type fluxgate) sensor is simple with manufacture craft, at low cost, and small, spirit is influenced by electronic noise
Sensitivity is high and the advantages that being easy to digital measurement.Therefore it is domestic also to start to grind for the correlation of RTD type fluxgate sensors therewith
Study carefully work, the domestic viewpoint of foreign scholar and existing knowledge of mainly absorbing realizes high-precision and can control pumping signal
The design of device also tentatively realizes the research and analysis for RTD type Fluxgate Techniques, but can not still remove interference and reach
To required precision.
Utility model content
The technical problem to be solved by the utility model is to provide a kind of cascade coupling RTD fluxgates Self-excitation Detection electricity
Road overcomes the problems, such as the interference of external signal present in existing fluxgate sensor and RTD fluxgates.
The utility model is realized in this way a kind of cascade coupling RTD fluxgates Self-excitation Detection circuit, the circuit include:
Multigroup RTD fluxgates tandem coupling, wherein：
Every group of RTD magnetic fluxs gate output terminal connection instrument amplifier is amplified the output signal of RTD fluxgates；
The signal amplified through the instrument amplifier is changed into approximate rectangular wave via integrating circuit；
The output terminal of the integrating circuit connects the first add circuit, and rectangular wave is high via the first add circuit adjustment waveform
Degree prevents direct current biasing；
The output terminal connection amplifying circuit of first add circuit, via amplifying circuit adjustment output polarity and letter
Number amplitude size；
The rectangular wave of amplified signal is removed noise by filter circuit by the filter circuit, the filter circuit with it is another
One group of RTD fluxgate tandems；
The RTD fluxgates input terminal connects voltage-current converter circuit, the input terminal of the voltage-current converter circuit
The second add circuit is connected, the input terminal of second add circuit connects the filter circuit of other groups, realizes multigroup RTD magnetic fluxs
Door tandem coupling.
Further, the RTD fluxgates are single magnetic core fluxgate, by the sensing of the excitation coil and 1000 circles of 200 circles
Coil forms, and excitation coil is wound on induction coil on same magnetic core, and the magnetic core uses cobalt base amorphous band soft magnetic core.
Further, second add circuit uses debiasing add circuit, and including an operational amplifier U4, computing is put
The resistance R18 and resistance R16 of the inverting input connection parallel connection of big device U4, resistance R18 are connected to operation amplifier by resistance R17
The output terminal of device U4, the other end connection slide rheostat R19 of the resistance R18.
Further, the voltage-current converter circuit is serially connected using two LF412 operational amplifiers.
Further, the instrument amplifier uses AD620 amplifiers.
Further, the integrating circuit includes an operational amplifier U2, the inverting input of the operational amplifier U2
It is connected by resistance R2 with the output point of the instrument amplifier, the inverting input of the operational amplifier U2 passes through resistance R3
The output terminal of operational amplifier U2 is connected to after in parallel with capacitance C1.
Further, first add circuit uses debiasing add circuit, including an operational amplifier U21, computing
The resistance R4 and resistance R6 of the inverting input connection parallel connection of amplifier U21, resistance R6 are connected to operation amplifier by resistance R5
The output terminal of device U21, the other end connection slide rheostat R7 of the resistance R6.
Further, the filter circuit uses the operational amplifier reverse parallel connection with two LF412 models, two computings
Resistance R14 is connected among between amplifier.
Further, the amplifying circuit uses LF412 operational amplifiers.
Compared with prior art, advantageous effect is the utility model：The utility model cascade coupling RTD fluxgate self-excitations
Detection circuit is combined RTD fluxgates with self-excited circuit, so as to remove the interference of external signal, can further increase magnetic field
Measurement, the especially precision of weak magnetic survey.Except RTD fluxgates low cost in various fluxgates, model is small, high sensitive, low
The advantages such as noise level, low-power, and cascade coupling RTD fluxgates from more essential one difference of excitation device when with measurement
External drive electric current need not be introduced, which not only simplifies the workloads of magnetic measurement, and measurement error may be brought by decreasing
Factor.
Description of the drawings
Fig. 1 is that one embodiment of the utility model provides circuit module block diagram；
Fig. 2 is the circuit diagram that the utility model embodiment provides one group of RTD fluxgate and its mating circuit；
Fig. 3 is the circuit diagram that the utility model embodiment provides voltage-current converter circuit；
Fig. 4 is the circuit diagram for the second add circuit that the utility model embodiment provides；
Fig. 5 is the circuit diagram for the filter circuit that the utility model embodiment provides；
Fig. 6 is the circuit diagram for the amplifying circuit that the utility model embodiment provides；
Fig. 7 is the circuit diagram for the first add circuit that the utility model embodiment provides；
Fig. 8 is the circuit diagram for the integrating circuit that the utility model embodiment provides；
Fig. 9 is the circuit diagram for the instrument amplifier that the utility model embodiment provides；
1. second add circuit in figure, 2. voltage-current converter circuits, 3.RTD fluxgates, 4. instrument amplifiers, 5. integrations
Circuit, 6. first add circuits, 7. filter circuits, 8. amplifying circuits.
Specific embodiment
In order to make the purpose of the utility model, technical solutions and advantages more clearly understood, below in conjunction with attached drawing and implementation
Example, is further elaborated the utility model.It should be appreciated that specific embodiment described herein is only used to explain
The utility model is not used to limit the utility model.
Referring to shown in Fig. 1 combinations Fig. 2, for three groups of RTD fluxgate tandem coupling Self-excitation Detection circuits of use, the circuit bag
It includes:Multigroup RTD fluxgates tandem coupling, wherein：Every group of RTD magnetic fluxs gate output terminal connects instrument amplifier 4 to RTD fluxgates
Output signal be amplified；
Every group of RTD magnetic fluxs gate output terminal connection instrument amplifier is amplified the output signal of RTD fluxgates；
The signal amplified through the instrument amplifier 4 is changed into approximate rectangular wave via integrating circuit 5；
The output terminal of the integrating circuit 5 connects the first add circuit 6, and rectangular wave adjusts ripple via the first add circuit 6
Shape highly prevents direct current biasing；
The output terminal connection amplifying circuit 7 of first add circuit 6, output polarity is adjusted via the amplifying circuit 7
With signal amplitude size；
The rectangular wave of amplified signal is removed noise by filter circuit 8 by the filter circuit, the filter circuit with it is another
One group of RTD fluxgate tandems；
The RTD fluxgates input terminal connects voltage-current converter circuit 2, the input of the voltage-current converter circuit 2
The second add circuit 1 of end connection, the input terminal of second add circuit connect the filter circuit of other groups, realize multigroup RTD
Fluxgate tandem couples.
RTD fluxgates are single magnetic core fluxgate, are made of the excitation coil of 200 circles and the induction coil of 1000 circles, are swashed
It encourages coil to be wound on same magnetic core with induction coil, magnetic core uses cobalt base amorphous band soft magnetic core.Excitation coil and induction coil
It is wound on same magnetic core.Core material is this soft magnetic materials of cobalt base amorphous band, so as to form RTD fluxgates.
In order to realize that tandem couples, prepare add circuit and voltage-current converter circuit before RTD fluxgates to realize grade
Connection.
The output of RTD fluxgates connects the pcb board being made of analog circuit.Pcb board instrument amplifier, then concatenate product before this
Parallel circuit, afterwards by the first add circuit, then filtered circuit removal noise, finally by amplifying circuit.Tandem coupling
It is combined into and connects second pcb board in first the last of pcb board, second pcb board connects the 3rd, it is achieved thereby that tandem coupling
It closes.The unforced dynamical system of the usual overdamp of this circuit structure will not generate vibration, but when the coefficient of coup is more than some critical value
And under nonidentical primary condition, the structure of a individual event couplings of N (odd number) will generate self-excitation.First pass around RTD fluxgates
External magnetic field is received, the signal through the output of RTD fluxgates is positive negative pulse stuffing after realizing self-excitation, but amplitude very little, it is difficult to reach
Acquisition requirement.So output signal is made to be amplified by instrument amplifier is converted into what is gathered convenient for digital circuit by sharp pulse
Level signal, then approximate rectangular wave is changed by integrating circuit, adjusting waveform height through the first add circuit prevents directly
Stream biasing removes noise using filter circuit, adjusts output polarity finally by amplifying circuit and further improves signal width
It is worth size.
Referring to Fig. 4, the second add circuit is connected with RTD fluxgates, using debiasing add circuit, including an operation amplifier
The resistance R18 and resistance R16 of the inverting input connection parallel connection of device U4, operational amplifier U4, resistance R18 connect by resistance R17
It is connected to the output terminal of operational amplifier U4, the other end connection slide rheostat R19 of the resistance R18.Operational amplifier U4 is
LF412, resistance R18 are 10 kilo-ohms, and resistance R16 is 10 kilo-ohms, and resistance R17 is 10 kilo-ohms.Slide rheostat R19 is 10 kilo-ohms.
Referring to Fig. 3, voltage-current converter circuit is serially connected using two LF412 operational amplifiers U5.Others auxiliary
Resistance：The parameter of resistance R20, resistance R21, resistance R23 are respectively all 10 kilo-ohms.
Referring to Fig. 9, instrument amplifier uses AD620 amplifiers U1.Auxiliary resistance uses 10 kilo-ohms.
Referring to Fig. 8, integrating circuit includes an operational amplifier U2, the model LF412 of operational amplifier U2, operation amplifier
The inverting input of device U2 is connected by resistance R2 with the output point of the instrument amplifier, the reverse phase of the operational amplifier U2
Input terminal is connected to the output terminal of operational amplifier U2 by resistance R3 after in parallel with capacitance C1.Resistance R2 is 51 kilo-ohms, resistance
R3 is 100 kilo-ohms, and capacitance C1 is 10 nanofarads.
Referring to Fig. 7, the first add circuit uses debiasing add circuit, including an operational amplifier U21, operational amplifier
The resistance R4 and resistance R6 of the inverting input connection parallel connection of U21, resistance R6 are connected to operational amplifier U21's by resistance R5
Output terminal, the other end connection slide rheostat R7 of the resistance R6.Resistance R4 is 100 kilo-ohms, and resistance R5 is 100 kilo-ohms, electricity
It is 100 kilo-ohms to hinder R6.Slide rheostat R7 is 100 kilo-ohms.
Referring to Fig. 5, filter circuit uses the operational amplifier U31 reverse parallel connections with two LF412 models, and two computings are put
Resistance R14 is connected among between big device.
Referring to Fig. 6, amplifying circuit is electric using the inverting input connection of LF412 operational amplifier U3, operational amplifier U3
It is 10 kilo-ohms to hinder R8, and it is 50 kilo-ohms that resistance R9 is connected between inverting input and output terminal.
For single magnetic core fluxgate, excitation coil is wound on same the RTD fluxgates used in the present embodiment with induction coil
On a magnetic core, wherein HxTo be tested magnetic field, IeFor sinusoidal excitation current.Fluxgate core material is coercivity HcThe cobalt-based of very little
Amorphous band ideally always works in positive and negative saturation state, if positive saturation is held in a sinusoidal cycles of exciting current
The continuous time is T+, it is T to bear the saturation duration-.As tested magnetic field HxWhen being zero, there was only sinusoidal excitation current in coil, magnetic core is just
Negative saturation time is identical, i.e. Δ t=T+-T-=0；As tested magnetic field HxWhen being not zero, except time of exciting current generation in magnetic core
Outside the venue, also it has been superimposed Hx, it is equivalent to and gives exciting current one direct current biasing, the positive and negative saturation time of magnetic core is different at this time, i.e. Δ t=
T+-T-≠ 0, and the size and H of Δ txIt is related.If total magnetic field residing for magnetic core is H (t), IeThe excitation field cycle of generation is Te, width
It is worth for Hm, then
If H (t) reaches H for the first timecAt the time of be t1, hereafter first time arrival-HcAt the time of be t2, then have
It solves
So as to
The output time difference of RTD fluxgates is
Signal of the fluxgate signal processing circuit design through the output of RTD fluxgates is positive negative pulse stuffing, and amplitude very little, it is difficult to
Reach acquisition requirement and believe, it is necessary to design a signal processing circuit and sharp pulse is converted into the level gathered convenient for digital circuit
Number, T+And T-Pass through low and high level width means.Therefore fluxgate output signal is amplified by instrument amplifier, then by
Integrating circuit is changed into approximate rectangular wave, and adjusting waveform height through add circuit prevents direct current biasing, using filtering
Circuit removes noise, adjusts output polarity finally by amplifying circuit and further improves signal amplitude size, while in magnetic flux
Add circuit and voltage-current converter circuit are placed in front of the door to realize that cascade is prepared.The self-oscillation can be applied to quantitative measurment
Some faint signals.This characteristic comes from Hopf forks, all may in the system formed in any overdamp bistable unit
It generates, if but will be separated from each other or remove respective driving, vibration will not all generate, therefore self-oscillatory generation is intimately tied to
Suitable parameter selection and system running state.In general, overdamp bistable state dynamical equation can be used
It represents, in cascade coupling RTD fluxgate sensors, x (t) represents the magnetic induction intensity in ferromagnetics material, dynamical equation
It can be written asC is a systematic parameter related with temperature and material, and ε is faint letter to be measured
Number, the critical value and frequency of oscillation of the coefficient of coup are related with c and ε, after the coil of N number of coupling realizes self-oscillation, oscillation frequency
Rate is N times of some independent frequency of oscillation, and with the increase of N, the frequency of oscillation of some independent coil can reduce.Traditional
The signal source that magnetometer needs extraneous offer additional, since cascade coupling can realize self-oscillation, can be replaced as excitation
Extraneous power supply serves as excitation, therefore can realize low-power consumption, lower price and the smaller Magnetic Sensor of noise jamming.It should be from exciting
It swings and can be applied to some faint signals of quantitative measurment.The signal source that traditional magnetometer needs extraneous offer additional is as sharp
It encourages, but since cascade coupling can realize self-oscillation, extraneous power supply can be replaced to serve as excitation, therefore can realize low-power consumption, compared with
Low price and the smaller Magnetic Sensor of noise jamming.
The above is only the preferred embodiment of the utility model only, is not intended to limit the utility model, all at this
All any modification, equivalent and improvement made within the spirit and principle of utility model etc., should be included in the utility model
Protection domain within.
Claims (9)
1. a kind of cascade coupling RTD fluxgates Self-excitation Detection circuit, which is characterized in that the circuit includes:Multigroup RTD fluxgates string
Grade coupling, wherein：
Every group of RTD magnetic fluxs gate output terminal connection instrument amplifier is amplified the output signal of RTD fluxgates；
The signal amplified through the instrument amplifier is changed into approximate rectangular wave via integrating circuit；
The output terminal of the integrating circuit connects the first add circuit, and rectangular wave is prevented via the first add circuit adjustment waveform height
Only there is direct current biasing；
The output terminal connection amplifying circuit of first add circuit, via amplifying circuit adjustment output polarity and signal width
It is worth size；
The rectangular wave of amplified signal is removed noise by filter circuit by the filter circuit, the filter circuit with another group
RTD fluxgate tandems；
The RTD fluxgates input terminal connects voltage-current converter circuit, the input terminal connection of the voltage-current converter circuit
Second add circuit, the input terminal of second add circuit connect the filter circuit of other groups, realize multigroup RTD fluxgates string
Grade coupling.
2. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that the RTD fluxgates
For single magnetic core fluxgate, be made of the excitation coil of 200 circles and the induction coil of 1000 circles, excitation coil and induction coil around
On same magnetic core, the magnetic core uses cobalt base amorphous band soft magnetic core.
3. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that second addition
Circuit uses debiasing add circuit, and including an operational amplifier U4, the inverting input of operational amplifier U4 connects parallel connection
Resistance R18 and resistance R16, resistance R18 are connected to the output terminal of operational amplifier U4 by resistance R17, and the resistance R18's is another
One end connection slide rheostat R19.
4. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that the voltage and current
Conversion circuit is serially connected using two LF412 operational amplifiers.
5. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that the instrument amplification
Device uses AD620 amplifiers.
6. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that the integrating circuit
Inverting input including operational amplifier a U2, the operational amplifier U2 is defeated by resistance R2 and the instrument amplifier
Go out connection, the inverting input of the operational amplifier U2 by resistance R3 it is in parallel with capacitance C1 after be connected to operational amplifier
The output terminal of U2.
7. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that first addition
Circuit uses debiasing add circuit, and including an operational amplifier U21, the inverting input connection of operational amplifier U21 is in parallel
Resistance R4 and resistance R6, resistance R6 is connected to the output terminal of operational amplifier U21 by resistance R5, and the resistance R6's is another
End connection slide rheostat R7.
8. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that the filter circuit
It is intermediate between two operational amplifiers to be connected with resistance R14 using the operational amplifier reverse parallel connection of two LF412 models.
9. cascade coupling RTD fluxgates Self-excitation Detection circuit as described in claim 1, which is characterized in that the amplifying circuit
Use LF412 operational amplifiers.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201721047146.7U CN207380223U (en) | 2017-08-21 | 2017-08-21 | A kind of cascade coupling RTD fluxgates Self-excitation Detection circuit |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201721047146.7U CN207380223U (en) | 2017-08-21 | 2017-08-21 | A kind of cascade coupling RTD fluxgates Self-excitation Detection circuit |
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| CN207380223U true CN207380223U (en) | 2018-05-18 |
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| CN201721047146.7U Expired - Fee Related CN207380223U (en) | 2017-08-21 | 2017-08-21 | A kind of cascade coupling RTD fluxgates Self-excitation Detection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112834815A (en) * | 2021-01-06 | 2021-05-25 | 唐新颖 | Fluxgate digital current sensor based on pulse amplitude detection method |
-
2017
- 2017-08-21 CN CN201721047146.7U patent/CN207380223U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112834815A (en) * | 2021-01-06 | 2021-05-25 | 唐新颖 | Fluxgate digital current sensor based on pulse amplitude detection method |
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| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20180518 Termination date: 20180821 |
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| CF01 | Termination of patent right due to non-payment of annual fee |