CN104054002A - Measurement method for magnetic field strength, flux-gate magnetic element, and magnetic sensor - Google Patents
Measurement method for magnetic field strength, flux-gate magnetic element, and magnetic sensor Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/04—Measuring direction or magnitude of magnetic fields or magnetic flux using the flux-gate principle
- G01R33/05—Measuring direction or magnitude of magnetic fields or magnetic flux using the flux-gate principle in thin-film element
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/04—Measuring direction or magnitude of magnetic fields or magnetic flux using the flux-gate principle
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Abstract
In the present invention, a flux-gate magnetic element formed on a non-magnetic substrate is provided with a magnetic body core, an exciting coil that is wound around the magnetic body core, a detection coil that is wound around the magnetic body core, and a feedback coil that is wound around the magnetic body core.
Description
The application is based on advocating right of priority No. 2012-083253 in the Patent of Japanese publication on March 30th, 2012, and its full content is quoted so far.
Technical field
The present invention relates to measuring method, fluxgate type magnetic cell and the Magnetic Sensor of magnetic field intensity.
Background technology
In the past, as the magnetic cell for measuring magnetic field intensity, known had a fluxgate type magnetic cell.Fluxgate type magnetic cell possesses small-sized and highly sensitive such feature, be used as measuring earth magnetism electronic compass, measure the magnetic field intensity that excites of electric current and be scaled the current sensor of current value.
As an example of fluxgate type magnetic cell in the past, there is the disclosed fluxgate type of patent documentation 1 magnetic cell.The fluxgate type magnetic cell of patent documentation 1 is wound with excitation coil and magnetic test coil on film-form magnetic core.
Detection principle below the fluxgate type magnetic cell utilization of patent documentation 1 is exported magnetic field intensity.
First, apply the triangular wave exciting current with constant cycle variation to the excitation of reeling with coil on magnetic core material.Utilize the wavy excitation field of triangle being produced by this triangular wave exciting current, magnetic core carries out the reversion of magnetic saturation and direction of magnetization repeatedly along BH curve.In the time of this direction of magnetization reversion, produce the voltage signal of pulse type at magnetic test coil.
Set the external magnetic field applying as measured magnetic field herein.Because the excitation field being produced by triangular wave exciting current can be coupled with external magnetic field, the big or small amount of displacement on the opportunity external magnetic field that pulse voltage signal produces.Change by extracted the time that this pulse voltage signal produces by testing circuit, can obtain the output corresponding with the size of external magnetic field.
Patent documentation 1:WO2010/134348
Summary of the invention
There is such technical matters of following explanation in fluxgate type magnetic cell in the past.
The magnetic core of fluxgate type magnetic cell has the magnetic saturation characteristic of BH curve such shown in the dotted line of Fig. 4.This BH curve is with chart initial point Central Symmetry, has the region that the relation that is applied between the magnetic field H of magnetic core and the magnetic flux density B of magnetic core linearly changes.Fluxgate type magnetic cell utilizes the magnetic saturation characteristic of this linearity region to measure magnetic field intensity.
In the magnetic core being formed by general magnetic material, if be applied in external magnetic field, the magnetic saturation characteristic of magnetic core changes, and shown in the solid line of Fig. 4, the linearity (rectilinearity) of the linearity region in BH curve also changes like that.Owing to applying external magnetic field, become the state that is related to sexual disorder between magnetic field H and magnetic flux B.And this disorderly degree is according to the scope of the external magnetic field being applied in and difference more applies large external magnetic field, the degree of the linear deterioration of BH curve is also larger.
Due to above-mentioned reason, change the opportunity that the pulse-like voltage signal producing in above-mentioned magnetic test coil produces according to the scope of external magnetic field, particularly, in the situation that being applied in large magnetic field, is difficult to measure accurately magnetic intensity.
The invention provides measuring method, fluxgate type magnetic cell and the Magnetic Sensor of magnetic field intensity, in above-mentioned fluxgate type magnetic cell, even if be applied in large external magnetic field, also can measure accurately magnetic field intensity.
The fluxgate type magnetic cell that first method of the present invention relates to is formed in the fluxgate type magnetic cell on non-magnetic substrate, possesses: magnetic core; Be wound on the field coil on above-mentioned magnetic core; Be wound on the magnetic test coil on above-mentioned magnetic core; And be wound on the tickler on above-mentioned magnetic core.
The fluxgate type magnetic cell that first method according to the present invention relates to, owing to being provided with tickler, so can apply the such feedback magnetic field in measured magnetic field of offsetting in magnetic core.Therefore, the effective magnetic field intensity in magnetic core can be reduced, the magnetic field intensity of the magnetic saturation characteristic that has utilized the good state of the rectilinearity of the BH curve that represents magnetic core magnetic saturation characteristic can be measured.Thus, can provide the fluxgate type magnetic cell that can measure accurately magnetic field intensity.
The Magnetic Sensor that second method of the present invention relates to possesses: fluxgate type magnetic cell, and above-mentioned fluxgate type magnetic cell possesses magnetic core; With the first solenoid coil and the second solenoid coil that are wound on above-mentioned magnetic core, a solenoid coil in above-mentioned the first solenoid coil and the second solenoid coil is field coil, another solenoid coil is magnetic test coil, and above-mentioned fluxgate type magnetic cell has the tickler being wound on above-mentioned magnetic core; With control integrated circuit, it provides feedback current to produce the feedback magnetic field of offsetting the measured magnetic field in above-mentioned magnetic core to above-mentioned tickler, and the value based on this feedback current is exported the intensity in measured magnetic field.
The Magnetic Sensor that second method according to the present invention relates to, owing to applying feedback magnetic field from tickler to offset the measured magnetic field magnetic core, so even if be applied in larger measured magnetic field, also can reduce the effective magnetic field intensity in magnetic core.Therefore, can measure and utilize representing the magnetic field intensity of magnetic saturation characteristic of BH curve cathetus kilter of magnetic core magnetic saturation characteristic, can measure accurately magnetic field intensity.Thus, do not depend on magnetic core magnetic characteristic and the scope of the magnetic field intensity measured can not be restricted, can obtain having maintained the output of the linearity (rectilinearity) as magnetic cell.
The measuring method of the magnetic field intensity that Third Way of the present invention relates to, to use the measuring method that possesses magnetic core and be wound on the magnetic field intensity of the fluxgate type magnetic cell of field coil, magnetic test coil and tickler on above-mentioned magnetic core, above-mentioned tickler produces the feedback magnetic field of offsetting the measured magnetic field in above-mentioned magnetic core, and the value of the electric current of above-mentioned fluxgate type magnetic cell based on providing to above-mentioned tickler is exported the intensity in measured magnetic field.
The measuring method of the magnetic field intensity that Third Way according to the present invention relates to, owing to applying feedback magnetic field from tickler to offset the measured magnetic field magnetic core, even so be applied in larger measured magnetic field, also can reduce the effective magnetic field intensity in magnetic core.Therefore, represent that the linearity of the BH curve of magnetic core magnetic saturation characteristic does not change, can measure the magnetic field intensity of having utilized the good magnetic saturation characteristic of rectilinearity, can measure accurately magnetic field intensity.
The measuring method of the magnetic field intensity that cubic formula of the present invention relates to is the measuring method of the magnetic field intensity that relates to according to Third Way, and the intensity of above-mentioned feedback magnetic field also can be roughly the same with the magnetic field intensity in measured magnetic field.
According to the measuring method of the magnetic field intensity of the fluxgate type magnetic cell that has used cubic formula of the present invention to relate to, the magnetic field that is effectively applied to magnetic core is almost nil, the magnetic field intensity of the magnetic saturation characteristic that has utilized the state the best at BH curve cathetus can be measured, magnetic field intensity can be measured more accurately.
The measuring method of the magnetic field intensity that the 5th mode of the present invention relates to is the measuring method of the magnetic field intensity that relates to according to Third Way or cubic formula, and the current value of the electric current providing to above-mentioned tickler can decide in the output based on from above-mentioned magnetic test coil.
According to the measuring method of the magnetic field intensity of the fluxgate type magnetic cell that has used the 5th mode of the present invention to relate to, due to the value based on the electric current providing to tickler is provided from the output of magnetic test coil, so do not depend on the magnetic characteristic of magnetic core, can obtain having maintained the output of the linearity (rectilinearity) as magnetic cell.
The fluxgate type magnetic cell that first method according to the present invention relates to, owing to being provided with tickler, therefore can apply the such feedback magnetic field in measured magnetic field of offsetting in magnetic core.Therefore, can reduce the effective magnetic field intensity in magnetic core, measure the magnetic field intensity of the magnetic saturation characteristic of the good state of the rectilinearity of the BH curve that represents magnetic core magnetic saturation characteristic.Thus, can provide the fluxgate type magnetic cell that can measure accurately magnetic field intensity.
Brief description of the drawings
Fig. 1 is the schematic diagram of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.
Fig. 2 is the chart that represents the spontaneous polarization curve in magnetic core.
Fig. 3 is the spontaneous polarization curve that the magnetized state of the magnetic core of the fluxgate type magnetic cell of the Magnetic Sensor that represents that the first embodiment of the present invention relates to changed according to the time.
Fig. 4 is the chart of the principle of work of the fluxgate type Magnetic Sensor of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.
Fig. 5 is the schematic top plan view of the fluxgate type magnetic cell of the Magnetic Sensor that summarily represents that the first embodiment of the present invention relates to.
Fig. 6 is the drawing in side sectional elevation cutting along the line a-a ' of Fig. 5.
Fig. 7 A is the sectional view cutting along the line b-b ' in Fig. 5, is the orthogonal view that represents the manufacturing process of fluxgate type magnetic cell.
Fig. 7 B is the sectional view cutting along the line b-b ' in Fig. 5, is the orthogonal view that represents the manufacturing process of fluxgate type magnetic cell.
Fig. 7 C is the sectional view cutting along the line b-b ' in Fig. 5, is the orthogonal view that represents the manufacturing process of fluxgate type magnetic cell.
Fig. 7 D is the sectional view cutting along the line b-b ' in Fig. 5, is the orthogonal view that represents the manufacturing process of fluxgate type magnetic cell.
Fig. 7 E is the sectional view cutting along the line b-b ' in Fig. 5, is the orthogonal view that represents the manufacturing process of fluxgate type magnetic cell.
Fig. 8 is the orthogonal view of other examples of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.
Fig. 9 is the vertical view of other examples of the fluxgate type magnetic cell of the Magnetic Sensor that summarily represents that the first embodiment of the present invention relates to.
Figure 10 is the chart of the principle of work of the fluxgate type Magnetic Sensor of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.
Figure 11 is the chart of the principle of work of the fluxgate type Magnetic Sensor of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.
Figure 12 is the chart of the principle of work of the fluxgate type Magnetic Sensor of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.
Figure 13 is the linear chart in the experimental example of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.
Figure 14 is the schematic top plan view of other examples of the fluxgate type magnetic cell of the Magnetic Sensor that summarily represents that the first embodiment of the present invention relates to.
Embodiment
Below, the Magnetic Sensor based on accompanying drawing, the first embodiment of the present invention being related to describes.
Fig. 1 is the schematic diagram of the Magnetic Sensor that represents that the first embodiment of the present invention relates to.In Fig. 1, Reference numeral MS10 represents Magnetic Sensor.
The Magnetic Sensor MS10 that the first embodiment of the present invention relates to possesses as shown in Figure 1 fluxgate type magnetic cell M12 and controls with integrated circuit (signal processing circuit) MT10.
Fluxgate type magnetic cell M12 has the field coil 9, magnetic test coil 10 and the tickler 21 that are wound on the magnetic core 1 being made up of soft magnetic material.
Control has exciting current with integrated circuit MT10 and produces circuit MT11, sensor amplifier (Sense amplifier) MT12, comparer MT13, feedback control circuit (FB control circuit) MT14, current amplifier MT15 and lead-out terminal MT16.
Magnetic Sensor MS10 is for example the current sensor for measuring the measured magnetic field exciting at the mobile electric current of conductive path etc.
Field coil 9 produces circuit MT11 with exciting current and is connected.Like that providing and becoming the exciting current of continuous wave signal to field coil 9 as hereinafter described.
Magnetic test coil 10 is connected with sensor amplifier MT12.In sensor amplifier MT12, be exaggerated from the output signal of magnetic test coil 10.Sensor amplifier MT12 is connected with comparer MT13.Comparer MT13 is connected with feedback control circuit MT14.Feedback control circuit MT14 is connected with current amplifier MT15.Current amplifier MT15 is connected with tickler 21 and lead-out terminal MT16.
The triangular wave exciting current that exciting current produces circuit MT11 generation is provided for field coil 9, produces excitation field therewith at magnetic core 1 together.The positive and negative alternately variation of magnetic direction of the excitation field producing at magnetic core 1.At magnetic test coil 10, produce pulse type induced voltage signal (detection signal) opportunity of switching at magnetic direction.The pulse type induced voltage signal (detection signal) producing at magnetic test coil 10 is inputted to sensor amplifier MT12 by the terminal being connected with magnetic test coil 10.This detection signal is amplified to the degree that the comparer MT13 of rear class can move by sensor amplifier MT12.
Comparer MT13 is transfused to the detection signal having been amplified by sensor amplifier MT12.The magnitude of voltage of comparer MT13 to this detection signal being exaggerated and the threshold voltage value having predetermined compare, and export the signal of High (height) value or Low (low) value according to its result.So like this, detection signal is converted to PWM (Pulse Width Modulation) waveform by comparer MT13.
Holding time of the High value of comparer MT13 output is called as " dutycycle " with the ratio of holding time of Low value.If this dutycycle is 50:50, for being not applied to the state in external magnetic field (measured magnetic field).If depart from 50:50, for being applied in the state in external magnetic field (measured magnetic field).More depart from 50:50, represent to be applied in larger external magnetic field (measured magnetic field).
Holding time of High value in the output as from comparer MT13 departed from 50:50 with the dutycycle of holding time of Low value, and feedback control circuit MT14 exports the d. c. voltage signal of the value corresponding with this bias.
The d. c. voltage signal of current amplifier MT15 based on feedback control circuit MT14 output, is provided for making dutycycle to approach the feedback current of 50:50 to tickler 21.Thus, the magnetized state in magnetic core becomes the state that is not effectively applied external magnetic field.
The measuring method of the magnetic field intensity of the first embodiment of the present invention is described by forming the principle of work of fluxgate type magnetic cell M12 etc. of Magnetic Sensor MS10.
Fig. 2 is the chart that represents the principle of work of fluxgate type magnetic cell.Fig. 2 (a) is the chart that the time variation of the triangular wave exciting current providing to field coil is provided.Fig. 2 (b) is the chart that represents the time variation of the magnetized state of core.Fig. 2 (c) is the chart that is illustrated in the time variation of the detection signal of magnetic test coil generation.Fig. 3 be represent fluxgate type magnetic cell M12 magnetic core magnetized state based on the time change BH curve (spontaneous polarization curve).
Provide the triangular wave exciting current as shown in Fig. 2 (a) if produce circuit MT11 from exciting current to field coil 9, the excitation field Hexc exciting due to field coil 9 and produce excitation field at magnetic core 1.The transverse axis of Fig. 2 (a) represents the time, and the longitudinal axis represents current value.Magnetic core 1 is owing to having magnetic saturation characteristic as shown in figure 3, so the temporal evolution as shown in Fig. 2 (b) of the magnetized state in magnetic core 1.The transverse axis of Fig. 2 (b) represents the time, and the longitudinal axis represents the magnetic flux density B in magnetic core 1.Be the time to change the opportunity that dB/dt exists the opportunity in the reversal of poles of the magnetized state of magnetic core 1, produces to the sectional area S of magnetic core 1, selects the proportional induced voltage Vpu=NS × dB/dt of number of turn N of coil 10 at magnetic test coil 10.The induced voltage Vpu producing at magnetic test coil 10 is time dependent pulse type induced voltage signal (detection signal) as shown in Fig. 2 (c).The transverse axis of Fig. 2 (c) represents the time, and the longitudinal axis represents magnitude of voltage.The time of the magnetic flux density B of magnetic core 1 changes dB/dt greatly, and the wave height value of induced voltage signal is higher, and pulse width is narrower, can obtain the induced voltage signal of more precipitous pulse type waveform.Magnetic field intensity H while using the magnetic flux density B of external magnetic field (measured magnetic field) Hext, magnetic core 1 to increase and between the time of minimizing departs from Hc, the magnetic field H exc that field coil 9 excites, the cycle T of triangular wave exciting current and Td time delay based on coil inductance, comes suc as formula the time interval t1 in presentation graphs 2 (c) like that shown in (1).
[several 1]
Similarly, suc as formula the time interval t2 in (c) of presentation graphs 2 like that shown in (2).
[several 2]
Through type (1) and formula (2), suc as formula the variable quantity t2-t1 that represents like that the time interval being produced by external magnetic field shown in (3).
[several 3]
Through type (3), the variation t2-t1 in the known time interval being produced by external magnetic field depends on the cycle T of external magnetic field Hext and ratio Hext/Hexc and the triangular wave exciting current of the excitation field Hexc being excited by field coil 9.Use the amplitude Iexc of the triangular wave exciting current of switching on to field coil 9, in the generation magnetic field (excitation efficiency α) of the per unit electric current of the mobile triangular wave exciting current of field coil 9 and the cycle T of triangular wave exciting current, represent sensitivity S=d (the t2-t1)/dHext for external magnetic field with S=T/ (2Iexc × α).Thus, the amplitude Iexc of triangular wave exciting current is larger, and the sensitivity S of fluxgate type magnetic cell M12 is less.Then, the cycle T of triangular wave exciting current is larger, and the sensitivity S of fluxgate type magnetic cell is larger.
Excitation efficiency α is the value determining by forming the magnetic core 1 of fluxgate type magnetic cell M12 and the number of turn of field coil 9.Excitation efficiency α is larger, in the situation that will measuring same sensitivity, same magnetic field scope, can drive fluxgate type magnetic cell M12 with less electric current.In addition, in formula (3), in the time becoming external magnetic field Hext=excitation field Hexc, formula (3) becomes 0, and external magnetic field Hext now becomes the upper limit of the magnetic field range that can measure.Owing to utilizing Hexc=α × Iexc to show, therefore become excitation efficiency α larger, in the situation that driving with same current, there is the fluxgate type magnetic cell of the wider magnetic field range that can measure.
This excitation efficiency α represents the ratio of magnetic flux density by field coil 9 is produced at magnetic core 1 by triangular wave exciting current and the magnetic flux density producing at magnetic core 1 due to external magnetic field.Excitation efficiency α, is represented by formula (4) with respect to the slope dB/dHext of external magnetic field Hext, determine with respect to the ratio of the slope dB/dIexc at the mobile triangular wave exciting current Iexc of field coil with the magnetic flux density B of identical magnetic core 1 by the magnetic density B in the non-saturated area of the spontaneous polarization curve of magnetic core 1.
[several 4]
Geomagnetic sensor MS10 is from controlling the exciting current that the triangular waveform of continuous shaking is provided to field coil 9 with the exciting current generation circuit MT11 of integrated circuit (signal processing circuit) MT10 as described above, and the flow direction in magnetic core 1 vibrates continuously and produces saturated magnetic field.In magnetic core 1, on the opportunity of flow direction reversion, produce the induced voltage of pulse type at magnetic test coil 10.Time interval T0 according to the induced voltage signal that makes the pulse type of exporting from this magnetic test coil 10 becomes minimum mode in the difference that does not apply the situation of external magnetic field Hext and apply the situation of external magnetic field Hext, provides feedback current to the tickler 21 being wound on magnetic core 1.
Use Figure 10～Figure 12 to describe principle of work more specifically.
(situation of external magnetic field Hext=0)
As shown in Figure 10 (a), exciting current produces circuit MT11 and provides the triangular wave exciting current with cycle T variation to field coil 9.Produce excitation field at magnetic core 1 therewith together.Figure 10 (b) represents that the time of the magnetized state in magnetic core 1 changes.Due to external magnetic field Hext=0, so the magnetized state in magnetic core 1 is only subject to the impact of excitation field, synchronously change with triangular wave exciting current.Thus, on the opportunity identical with moment t2, t4, t6, the t8 of the reversal of poles of triangular current, magnetized state (direction of magnetization) reversion in magnetic core 1.Figure 10 (c) is illustrated in the pulse type induced voltage signal that magnetized state when reversion of magnetic core 1 produces at magnetic test coil 10.Moment t2 and t6 at the magnetized state of magnetic core 1 from negative sense rotating, produce the induced voltage signal K+ of positive sign.Bear moment t4 and the t8 of reversion at the magnetized state of magnetic core 1 from forward, produce the induced voltage signal K-of negative sign.
The induced voltage signal (K+, K-) producing at magnetic test coil 10 is transfused to as the output of fluxgate type magnetic cell M12 to control uses integrated circuit MT10.First, induced voltage signal is exaggerated at sensor amplifier MT12, is then transfused to comparer MT13.Comparer MT13 as shown in Figure 10 (d) by the induced voltage signal being exaggerated to PWM (Pulse Width Modulation) waveform modulated.Magnitude of voltage to the induced voltage signal being exaggerated and the threshold voltage value that predetermined compare, in the case of the magnitude of voltage of the induced voltage signal that has been exaggerated is larger, output has maintained the voltage signal of High, and in the case of the induced voltage signal that has been exaggerated is less, output has maintained the voltage signal of Low.The time width that maintains High is made as to T
h, the time width that maintains Low is made as to T
l, the in the situation that of outside magnetic field H ext=0, T
h=T
l, this is set as interval T 0 (zero) reference time.Reference time, interval T 0 equated with the half period T/2 of triangular current.Time width (the T of High
h) and the time width (T of Low
l) between dutycycle become T0:T0 (=50:50).
Input the signal modulated at comparer MT13 to LPF (low-pass filter) feedback control circuit 14.Signal is output to tickler 21 via feedback control circuit MT14, current amplifier MT15 as feedback current, and is exported continuously as the output of the Magnetic Sensor of the index of expression external magnetic field strength from lead-out terminal MT16 from the output valve of current amplifier MT15.This output becomes the output in the Hext=0 of external magnetic field.
(situation of external magnetic field Hext > 0)
With the situation of the external magnetic field Hext=0 shown in Figure 10 (a) in the same manner, if the triangular current shown in Figure 11 (a) is provided for field coil 9, produce excitation field at magnetic core 1.Magnetized state in magnetic core 1 is also subject to the impact of external magnetic field Hext except excitation field.Therefore, the chart of the time variation of the magnetized state in expression magnetic core 1 becomes the waveform that is Figure 10 (b) as shown in Figure 11 (b) to the shape of a side (Figure 11 (b) is minus side) displacement.So, become the opportunity of magnetized state (direction of magnetization) in magnetic core 1 reversion not with the variation of the triangular current of field coil 9 and synchronize.For example, the direction of magnetization of magnetic core, from opportunity from moment t2, the t6 displacement of negative sense rotating, approaches respectively moment t3, t7.Therefore also approach moment t3, t7 (Figure 11 (c)) opportunity that, the pulse type induced voltage signal K+ of positive sign produces.On the other hand, the direction of magnetization of magnetic core 1 also from moment t4, t8 displacement, approaches respectively moment t3, t7 from the opportunity of the negative reversion of forward.Therefore also approach moment t3, t7 (Figure 11 (c)) opportunity that, the induced voltage signal K-of the pulse type of negative sign produces.
As its result, the time width T of the High after comparer MT13 is modulated
htime width T with Low
lalso change, as shown in Figure 11 (d), become T
h< T
l.By T now
hbe made as T1, by T
lbe made as T2, T1 become than reference time interval T 0 little, T2 become than reference time interval T 0 large.Corresponding to this reference time interval T 0 provide feedback current from current amplifier MT15 to tickler 21 with the residual quantity of T1, T2 so that produce eliminate the impact of external magnetic field Hext such with the rightabout magnetic field of external magnetic field Hext.Eliminate the such direction of external magnetic field Hext and big or small feedback magnetic field Hfb because tickler 21 produces to have, so can reduce the external magnetic field Hext in magnetic core 1, maintain near the magnetic field state of of external magnetic field Hext=0.
Use BH curve is explained, even if be applied in external magnetic field Hext > 0, the state variation that the magnetized state of magnetic core 1 does not also reduce to the linearity (rectilinearity) of BH curve, can measure the magnetic intensity of the magnetic saturation characteristic that has utilized linear good state.Thus, even if be applied in larger external magnetic field, the effective magnetized state due to feedback magnetic field in magnetic core approaches the state of external magnetic field Hext=0, can measure the magnetic field intensity of having utilized linear good BH curve.
In addition exported continuously as the output of the Magnetic Sensor of expression external magnetic field strength by terminal MT16 from the output of current amplifier MT15.
(situation of external magnetic field Hext < 0)
If provide the triangular current as shown in Figure 12 (a) (identical with Figure 10 (a), Figure 11 (a)) to field coil 9, produce excitation field at magnetic core 1.Magnetized state in magnetic core 1 is also subject to the impact of external magnetic field Hext except excitation field.The in the situation that of said external magnetic field H ext > 0, due to counteractive action, the time width T of the High after comparer MT13 is modulated
htime width T with Low
las shown in Figure 12 (d), become T
h> T
l.By T now
hbe made as T3, by T
lbe made as T4, T3 become than reference time interval T 0 large, T4 become than reference time interval T 0 little.Corresponding to the residual quantity of this interval T 0, T3 and T4 reference time, provide feedback current 21 from current amplifier MT15 to tickler 21 so that produce eliminate external magnetic field Hext such with the rightabout magnetic field of external magnetic field Hext.Eliminate the such direction of external magnetic field Hext and big or small feedback magnetic field Hfb because tickler 21 produces to have, so can eliminate the external magnetic field Hext in magnetic core 1, maintain near the magnetic field state of external magnetic field Hext=0.
Use BH curve is explained, even if be applied in external magnetic field Hext < 0, the state variation that the magnetized state of magnetic core 1 does not also reduce to the linearity (rectilinearity) of BH curve, can measure the magnetic intensity that has utilized linear good magnetic saturation characteristic.Thus, even if be applied in larger external magnetic field, the effective magnetizing state due to feedback magnetic field in magnetic core approaches the state of external magnetic field Hext=0, can measure the magnetic field intensity of having utilized linear good BH curve.
In addition exported continuously as the output of the Magnetic Sensor of expression external magnetic field strength by terminal MT16 from the output of current amplifier MT15.
Based on above such principle, provide feedback current to tickler 21.The output signal of the external magnetic field strength of then, exporting from terminal MT16 can be exported as the analogue value of continuous variable quantity.Or also can utilize the method for digitally counting peak intervals.
In addition, export feedback current corresponding to the pulse signal K+ changing according to external magnetic field Hext, the time interval of K-, can also flow to field coil 9, magnetic test coil 10 but this feedback current not only can flow to tickler 21.In this situation, can be by making a part for feedback current and offering the triangular current of field coil 9, the overlapping realization of induced voltage signal that magnetic test coil produces.
And, in the situation that flowing through feedback current to field coil 9, magnetic test coil 10, as shown in Figure 9, can make double field coil 9 and the magnetic test coil 10 of doing of tickler 21.In this situation, the feedback terminal of current amplifier MT15 is connected with field coil 9 or magnetic test coil 10.
Next, magnetic cell M12 is described.
The magnetic cell M12 of present embodiment can be for for example having used the fluxgate type element of phase-shift delay method (phase-delay method).The long side direction of the magnetic core 1 of magnetic cell M12 is consistent with the sense magnetic direction of the magnetic cell M12 of fluxgate.
Fig. 5 is the vertical view of the fluxgate type magnetic cell that summarily represents that the first embodiment of the present invention relates to.Fig. 6 is the drawing in side sectional elevation cutting along the line a-a ' in Fig. 5.Fig. 7 A～Fig. 7 E is the orthogonal view that represents the manufacturing process of cutting along the line b-b ' in Fig. 5.
The fluxgate type magnetic cell M12 that the first embodiment of the present invention relates to as shown in Figure 5, Figure 6, has magnetic core 1, the first wiring layer 4, the first insulation course 5, the second insulation course 6, the second wiring layer 7, peristome 8 and substrate M13.The first wiring layer 4 and the second wiring layer 7 form the field coil (solenoid coil) 9, magnetic test coil (solenoid coil) 10 and the tickler (solenoid coil) 21 that are wound on magnetic core 1.
The flat shape of magnetic core 1 is the shape with long side direction, and its section shape is the film shape that magnetic material film forming is formed.
Field coil 9, magnetic test coil 10 and tickler 21 spread all over magnetic core 1 long side direction total length and form.Then, each wiring is wound into triple helical in the mode of almost parallel.
Use Fig. 7 A～Fig. 7 E, the formation method of the fluxgate type magnetic cell that present embodiment is related to describes.
As shown in Figure 7 A, on nonmagnetic substrate M13, be formed for the first wiring layer 4 of the downside wiring that forms solenoid coil.Next, as shown in Figure 7 B, on the first wiring layer 4, be formed for the first insulation course 5 of magnetic core 1 and solenoid coil insulation.On the first insulation course 5, connect the first wiring layer 4 and be provided with peristome 8 with the part of the second wiring layer 7 of the upside wiring that becomes solenoid coil forming afterwards.
As shown in Fig. 7 C, on the first insulation course 5, form the magnetic core 1 being formed by soft-magnetic body film.Next,, as shown in Fig. 7 D, the connecting portion that is formed on the first wiring layer 4 and the second wiring layer 7 on magnetic core 1 is provided with the second insulation course 6 of peristome 8.On the second insulation course 6, as shown in Fig. 7 E, the adjacent wiring that connects the first wiring layer 4 in its end mode each other forms the second wiring layer 7, and forms solenoid coil.Because wiring is connected with the wiring adjacent at interval of two, so the ring of the solenoid coil in section is not closed.
Utilize the solenoid coil being formed by the first wiring layer 4 and the second wiring layer 7 that field coil 9, magnetic test coil 10 and tickler 21 are set.Any in them is all wound on magnetic core 1 independently.Two ends at magnetic test coil 10 form by the electrode pad 11 for being connected with outside.Be formed with the electrode pad 12 for being connected with outside at the two ends of field coil 9.Be formed with the electrode pad 13 for being connected with outside at the two ends of tickler 21.Electrode pad 11 be connected to the terminal of sensor amplifier MT12, electrode pad 12 is connected with the terminal that produces circuit MT11 to exciting current, electrode pad 13 be connected to the terminal of current amplifier MT15.
At this, field coil 9, magnetic test coil 10 and tickler 21 can be all that the number of turn is identical and symmetrical.Particularly, tickler 21 spreads all over the total length of magnetic core 1 and reels in the uniform mode of its this pitch.
In addition,, as shown in schematically illustrated these figure, omit the diagram of a part about each solenoid coil.In addition the thin portion shape of magnetic cell M12 be without ceasely limited to illustrated shape.
Magnetic core 1 is by switching on and by excitation to the field coil 9 of reeling around it.Then, if the reversion of the direction of magnetization of magnetic core 1 produces induced voltage at magnetic test coil 10.By from outside via electrode pad 12, field coil 9 being made to magnetic core 1 excitation by time dependent triangular current, produce the induced voltage of pulse type at magnetic test coil 10 by the reversing magnetic field producing.The induced voltage producing at magnetic test coil 10 is output to control via electrode pad 11 uses integrated circuit MT10.Then, carry out signal processing in control with the inside of integrated circuit MT10, be applied to tickler 21 as feedback current via electrode pad 13.
The first embodiment of the present invention is an example, and the configuration of magnetic core 1, field coil 9, magnetic test coil 10 and tickler 21 is not limited to said structure, can be other configuration.Particularly, field coil 9, magnetic test coil 10 and tickler 21 can be the configuration beyond triple helical.
For example, can be also the fluxgate type magnetic cell shown in Figure 14.For the fluxgate type magnetic cell shown in Figure 14, the flat shape of magnetic core 1 is the central portion of its long side direction by the shape of constriction, and both ends 1a is formed larger than central portion 1b width.Be wound with magnetic test coil 10 at the central portion of magnetic core 1, the both ends 1a large at width is wound with field coil 9.Then the total length that, spreads all over magnetic core 1 is wound with tickler 21.Then, be wound into triple helical according to the mode of each wiring almost parallel.In addition, at Fig. 5, Figure 14, in order to identify coil, represent with shade.In addition,, at Figure 14, omit the record of the structure beyond magnetic core 1, coil 9,10,21, electrode pad 11,12,13.
Magnetic Sensor M10 also can have demagnetization body M11 as shown in Figure 8.
In this situation, Magnetic Sensor M10 is made up of the demagnetization body M11 being made up of sheet-form soft-magnetic body installing in packaging body M10a, bonding wire (bonding wire) M15 that is formed on the fluxgate film magnetic cell M12 with magnetic core 1 on non-magnetic substrate M13 and electrical connecting wire frame M14 and magnetic cell M12.Magnetic cell M12 is arranged on tabular demagnetization body (sheet-form soft-magnetic body) M11 stackedly.The sense magnetic direction of Magnetic Sensor M10 is the direction parallel with substrate M13 surface.It is the soft-magnetic body of the fusing shapes such as ferrite such as noncrystal, the soft-magnetic body of sheet that demagnetization body M11 can use soft magnetic metal gonosome material, the Co such as such as NiFe.
Demagnetization body M11 is arranged on the position separating from magnetic core described later surface, reduce the external magnetic field Hext that flows into this first magnetic, in order to control the amount that is reduced the external magnetic field Hext that flows into magnetic core 1 by demagnetization body M11, substrate M13 is the distance configuration part of setting the distance between magnetic cell M12 demagnetization body M11.Be integrated apart from configuration part and magnetic cell M12.
Set the distance between demagnetization body M11 and magnetic cell M12 according to the thickness of substrate M13.Demagnetization body M11 is preferably formed the long side direction at magnetic cell M12 while overlooking, the wider region of covering compared with magnetic cell M12.Thus, the major part of the external magnetic field Hext body M11 that demagnetized absorbs, and the only part in the component of external magnetic field Hext is applied to the magnetic core 1 of magnetic cell M12.
In the first embodiment of the present invention, apply feedback magnetic field Hfb from tickler 21 to magnetic core 1, flow into external magnetic field (measured magnetic field) Hext of magnetic core 1 from outside and almost equal state when the Hext=0 of external magnetic field so that the magnetized state of magnetic core 1 becomes with eliminating.Thus, the region disorder departing from from zero point at outside magnetic field H ext to the linear of the BH curve of the situation of magnetic core 1 satisfied degree, magnetic core 1 greatly at outside magnetic field H ext, also can get rid of these impacts, the state higher with linear carries out the measurement of external magnetic field Hext.Therefore, can not depend on the structure (size of magnetic core, coil wiring etc.) of magnetic cell M12, become the Magnetic Sensor MS10 corresponding with the magnetic field intensity of relative broad range.Meanwhile, determine that the key element of the value of feedback current is only cycle T, field coil 9 and the excitation field of the triangular current that provides to field coil 9, the feedback magnetic field Hfb that tickler 21 excites, affect hardly the characteristic of magnetic core 1.Therefore,, compared with Magnetic Sensor in the past, the properties influence of element itself is very little.
In addition in the past, the time interval that only can set by the multiple of the long timer of the cycle T with than at the mobile triangular current of field coil 9, export intermittently magnetic field intensity output, but pass through present embodiment, can carry out continuously magnetic field intensity output, can improve the measuring accuracy as Magnetic Sensor.Particularly, with carry out the output based on timer with the cycle of 1mSec left and right compared with, in the present embodiment, can be almost without the time lag ground continuous wave output analogue value.
The first embodiment of the present invention is that magnetic cell M12 and control integrated circuit MT10 are the example of configuration singly, but also can use multiple magnetic cell M12, in this situation, control with integrated circuit MT10, use multiplexer etc. by increase, can be corresponding with the quantity of magnetic cell.In this situation, the multiple output of use such as measurement result by the multiple magnetic cell M12 of cross-reference is calculated, and more high precision is low measures.
(experimental example 1)
As experimental example 1, as shown in Figure 13, calculate the linear error when magnetic field H ext that will measure is changed.
At this, linear error Δ is exported Hout with respect to measurement and is,
Δ＝(Hout－Hext)/Hext×100(％)。
From this result, carrying out in the Magnetic Sensor of the feedback that embodiments of the present invention relate to, irrelevant with the scope of external magnetic field, linear raising.
Above, illustrate for the preferred embodiment of the present invention, but these illustrations that are only inventions do not limit the present invention, can append, delete, replace and other change in the scope that does not depart from the scope of the invention.Be the present invention and can't help above-mentioned embodiment and limit, and by the circumscription of claim.
Utilizability in generation
Fluxgate type magnetic cell of the present invention can be used as small size magnetic sensor, and this Magnetic Sensor can be as electronic azimuth finder etc. and is widely used in mobile phone, portable navigation device, game console etc. in addition.As the example of applying flexibly of the present invention, can enumerate the drive system of automobile, galvanometer to input-output line of accumulator etc. for large electric current.
Description of reference numerals:
M10, MS10 ... Magnetic Sensor; MT10 ... control integrated circuit; M12 ... magnetic cell; 1 ... magnetic core; 9 ... field coil; 10 ... magnetic test coil; 21 ... tickler; MT11 ... exciting current produces circuit; MT12 ... sensor amplifier; MT13 ... comparer; MT14 ... feedback control circuit; MT15 ... current amplifier; MT16 ... lead-out terminal.
Claims (5)
1. a fluxgate type magnetic cell, is formed on non-magnetic substrate, it is characterized in that possessing:
Magnetic core;
Be wound on the field coil on described magnetic core;
Be wound on the magnetic test coil on described magnetic core; And
Be wound on the tickler on described magnetic core.
2. a Magnetic Sensor, is characterized in that, possesses:
Fluxgate type magnetic cell, described fluxgate type magnetic cell is wound with the first solenoid coil and the second solenoid coil on magnetic core, a solenoid coil in described the first solenoid coil and the second solenoid coil is field coil, another solenoid coil is magnetic test coil, and has the tickler being wound on described magnetic core; With
Control integrated circuit, described control provides feedback current to produce the feedback magnetic field of offsetting the measured magnetic field in described magnetic core with integrated circuit to described tickler, and value based on this feedback current is exported the intensity in measured magnetic field.
3. a measuring method for magnetic field intensity, is the measuring method that uses the magnetic field intensity of fluxgate type magnetic cell, and described fluxgate type magnetic cell possesses: magnetic core; With the field coil, magnetic test coil and the tickler that are wound onto on described magnetic core, the measuring method of described magnetic field intensity is characterised in that,
Described tickler produces the feedback magnetic field of offsetting the measured magnetic field in described magnetic core,
The value of the electric current of described fluxgate type magnetic cell based on providing to described tickler is exported the intensity in measured magnetic field.
4. the measuring method of magnetic field intensity according to claim 3, is characterized in that,
The intensity of described feedback magnetic field and the magnetic field intensity in measured magnetic field are roughly the same.
5. according to the measuring method of the magnetic field intensity described in claim 3 or 4, it is characterized in that,
The output of the current value of the electric current providing to described tickler based on from described magnetic test coil decides.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012-083253 | 2012-03-30 | ||
| JP2012083253A JP5997919B2 (en) | 2012-03-30 | 2012-03-30 | Fluxgate type magnetic element and magnetic sensor |
| PCT/JP2013/059642 WO2013147207A1 (en) | 2012-03-30 | 2013-03-29 | Measurement method for magnetic field strength, flux-gate magnetic element, and magnetic sensor |
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| CN104054002A true CN104054002A (en) | 2014-09-17 |
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| CN201380005685.2A Pending CN104054002A (en) | 2012-03-30 | 2013-03-29 | Measurement method for magnetic field strength, flux-gate magnetic element, and magnetic sensor |
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| Country | Link |
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| JP (1) | JP5997919B2 (en) |
| CN (1) | CN104054002A (en) |
| WO (1) | WO2013147207A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107533114A (en) * | 2015-04-27 | 2018-01-02 | 艾沃思宾技术公司 | Magnetic field sensor with increased field scope |
| CN107966671A (en) * | 2016-10-19 | 2018-04-27 | Tdk株式会社 | Magnetic Sensor inductance element and the current sensor for possessing it |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6559558B2 (en) * | 2015-12-11 | 2019-08-14 | 本田技研工業株式会社 | Electromagnetic valve control device, vehicle electronic control device, and vehicle |
| CN109781832A (en) * | 2019-03-19 | 2019-05-21 | 哈尔滨工业大学（深圳） | A kind of method and excitation unit of coated steel strip damage check |
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| GB9408942D0 (en) * | 1994-05-05 | 1994-06-22 | Spicer Denis F | Magnetic field cancelling system |
| JPH08233927A (en) * | 1995-02-27 | 1996-09-13 | Shimadzu Corp | Thin film flux gate magnetic sensor and manufacture thereof |
| JPH08271598A (en) * | 1995-03-31 | 1996-10-18 | Shimadzu Corp | Magnetometer |
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| WO2010134348A1 (en) * | 2009-05-21 | 2010-11-25 | 株式会社フジクラ | Flux gate senior and electronic azimuth indicator making use thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2931945B1 (en) * | 2008-05-22 | 2010-06-18 | Billanco | MAGNETIC FIELD CIRCULATION SENSOR AND CURRENT SENSOR EMPLOYING SUCH A SENSOR |
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- 2012-03-30 JP JP2012083253A patent/JP5997919B2/en not_active Expired - Fee Related
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- 2013-03-29 WO PCT/JP2013/059642 patent/WO2013147207A1/en active Application Filing
- 2013-03-29 CN CN201380005685.2A patent/CN104054002A/en active Pending
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| GB9408942D0 (en) * | 1994-05-05 | 1994-06-22 | Spicer Denis F | Magnetic field cancelling system |
| WO1995030906A1 (en) * | 1994-05-05 | 1995-11-16 | Denis Frank Spicer | Magnetic field cancelling system |
| JPH08233927A (en) * | 1995-02-27 | 1996-09-13 | Shimadzu Corp | Thin film flux gate magnetic sensor and manufacture thereof |
| JPH08271598A (en) * | 1995-03-31 | 1996-10-18 | Shimadzu Corp | Magnetometer |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107533114A (en) * | 2015-04-27 | 2018-01-02 | 艾沃思宾技术公司 | Magnetic field sensor with increased field scope |
| CN107966671A (en) * | 2016-10-19 | 2018-04-27 | Tdk株式会社 | Magnetic Sensor inductance element and the current sensor for possessing it |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2013147207A1 (en) | 2013-10-03 |
| JP2013213696A (en) | 2013-10-17 |
| JP5997919B2 (en) | 2016-09-28 |
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