CN104280698B - Magnetic field measuring device - Google Patents
Magnetic field measuring device Download PDFInfo
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- CN104280698B CN104280698B CN201310286665.9A CN201310286665A CN104280698B CN 104280698 B CN104280698 B CN 104280698B CN 201310286665 A CN201310286665 A CN 201310286665A CN 104280698 B CN104280698 B CN 104280698B
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Abstract
The present invention provides a kind of magnetic field measuring device comprising probe, the voltage signal for incuding tested magnetic field and acquisition；Amplifier obtains voltage amplification signal for amplifying the voltage signal；Processor, the characteristic for obtaining the tested magnetic field according to the voltage amplification signal and probe described in the waveform in the tested magnetic field use the GMR Magnetic Sensors that the giant magnetoresistive thin film with giant magnetoresistance effect is formed.For the range of dynamic measurement of the magnetic field measuring device up to 80dB, bandwidth is up to 2MHz, and high sensitivity, at low cost.
Description
Technical field
The present invention relates to a kind of magnetic field measuring devices.
Background technology
Gaussmeter and fluxmeter are common in the market two kinds of magnetic field measuring devices, moreover, because gaussmeter is easy to operate, smart
Degree is higher, and application is more extensive.Most of gaussmeter sold currently on the market is to carry out magnetic field intensity based on Hall effect principle
It measures, that is, uses measuring probe of the Hall sensor as gaussmeter.It is limited to the material and characteristic of Hall sensor, measures and visits
Head generally use direct measuring type Hall voltage sensor.However, theoretically the measurement frequency of direct measuring type Hall voltage sensor is little
It is no more than 30kHz in the measurement frequency of 50kHz, commercially available high-end gaussmeter, range of dynamic measurement is no more than 70dB, and price
It is high.For normal Gaussian meter, although on the low side, measurement frequency is essentially 50Hz or 60Hz, and frequency bandwidth exists
2kHz or less.
Invention content
The technical problem to be solved in the present invention is to be directed to drawbacks described above present in magnetic field intensity measurement, a kind of magnetic is provided
Field measurement device, high certainty of measurement, range of dynamic measurement and measurement bandwidth, and it is at low cost.
For this purpose, the present invention provides a kind of magnetic field measuring device, including：
Probe, the voltage signal for incuding tested magnetic field and acquisition；
Amplifier obtains voltage amplification signal for amplifying the voltage signal；
Processor, characteristic and the tested magnetic field for obtaining the tested magnetic field according to the voltage amplification signal
Waveform；
The GMR Magnetic Sensors that the probe is formed using the giant magnetoresistive thin film with giant magnetoresistance effect.
Wherein, the characteristic in the tested magnetic field includes the intensity of D.C. magnetic field, the intensity of alternating current magnetic field and alternating current magnetic field
Frequency.
Wherein, the amplifier includes：
Precision amplifier is used to amplify the voltage signal, to obtain accurate amplification voltage signal；
Controllable amplifier is used to that the survey needed for the processor for the accurate amplification voltage signal to be further amplified
It measures within dynamic range, to obtain the voltage amplification signal.
Wherein, the precision amplifier includes amplifier INA322, first resistor R65, the electricity of second resistance R66 and first
Holding C47, the both ends of the first resistor R65 meet the pin RG0 and pin REF of the amplifier INA322 respectively, and described second
The both ends of resistance R66 meet the pin RG0 of the amplifier INA322 and the both ends point of pin VO, the first capacitance C47 respectively
It Jie Di not be with the pin REF of the amplifier INA322.
Wherein, the controllable amplifier includes：Analog switch U11, operational amplifier U8A, low-pass filter circuit, the 4th electricity
R76 and the 5th resistance R77 is hindered, the positive input and output end of the operational amplifier U8A is respectively as the controllable amplification
The input terminal and output end of device, the pin NO of the analog switch U11 meet the reverse input end of the operational amplifier U8A, institute
Low-pass filter circuit is stated between the reverse input end and output end of the operational amplifier U8A, the 4th resistance R76's
Both ends meet the pin COM and ground of the analog switch U11 respectively；The both ends of the 5th resistance R77 connect the simulation and open respectively
Close the control terminal IN and ground of U11.
Wherein, further include real effective unit comprising：
True effective value converting circuit is used for from extraction in the voltage amplification signal and alternation portion in the tested magnetic field
Voltage amplification signal corresponding to point, and it is converted into real effective voltage signal；
Filter circuit is used to filter the real effective voltage signal, to filter out high frequency noise；
Real effective processing module obtains the tested magnetic field according to the filtered real effective voltage signal
Real effective.
Wherein, the true effective value converting circuit includes the second analog switch U10 and third capacitance C49, the third electricity
The both ends for holding C49 meet the input terminal IN2 and ground of the second analog switch U10 respectively, and the third capacitance C49 uses 0.1 μ F
Capacitance, the second analog switch U10 use Linear Tech model LT1968 analog switch.
Wherein, further include memory module, for storing the characteristic in tested magnetic field, the waveform in the tested magnetic field and described
Real effective.
Wherein, further include：
Display unit, the waveform of characteristic and the tested magnetic field for showing the tested magnetic field；
Control unit, for the man-machine communication between operator and magnetic field measuring device；
Power supply unit, for providing electric energy for magnetic field measuring device.
Wherein, the display unit is liquid crystal display device or CRT display devices.
Wherein, the power supply unit is accumulator or AC power.
Wherein, further include：
Charhing unit, for charging to the accumulator；
Power Management Unit provides electric energy and the control accumulator charging for controlling the accumulator.
Wherein, further include：
USB communication interfaces, for being communicated between magnetic field measuring device and host computer.
The invention has the advantages that：
The GMR magnetic that magnetic field measuring device provided by the invention utilizes the giant magnetoresistive thin film with giant magnetoresistance effect to be formed senses
Device is probe, and the range of dynamic measurement of GMR Magnetic Sensors is up to 80dB, and bandwidth is up to 2MHz, and high sensitivity, cost
It is low.
Description of the drawings
Fig. 1 is the functional block diagram of the present embodiment magnetic field measuring device；
Fig. 2 is precision amplifier schematic diagram of the embodiment of the present invention；
Fig. 3 is controllable amplifier schematic diagram of the embodiment of the present invention；
Fig. 4 is real effective circuit conversion schematic diagram of the embodiment of the present invention；
Fig. 5 is filter circuit schematic diagram of the embodiment of the present invention.
Specific implementation mode
To make those skilled in the art more fully understand technical scheme of the present invention, the present invention is carried below in conjunction with the accompanying drawings
The magnetic field measuring device of confession is described in detail.
Fig. 1 is the functional block diagram of magnetic field measuring device of the embodiment of the present invention.As shown in Figure 1, magnetic field provided in this embodiment
Measuring device includes probe 1, amplifier 2 and processor 3.Wherein, probe 1 is using the giant magnetoresistive thin film shape with giant magnetoresistance effect
At GMR Magnetic Sensors, the voltage signal for incuding tested magnetic field and acquisition.The range of dynamic measurement of GMR Magnetic Sensors can
Up to 80dB, bandwidth 2MHz, and high sensitivity, linear characteristic is good, and superior performance is at low cost.
Amplifier 2 is for the 1 voltage signal amplification obtained that will pop one's head in, to obtain voltage amplification signal.Processor 3 is according to electricity
Amplified signal is pressed to obtain the spy in the tested magnetic fields such as the frequency of the intensity of D.C. magnetic field, the intensity of alternating current magnetic field and alternating current magnetic field
The waveform in property and tested magnetic field.
Amplifier 2 includes precision amplifier 21 and controllable amplifier 22.Wherein, precision amplifier 21 is also put as low noise
Big device, be used to pop one's head in the 1 voltage signal amplification obtained, and is converted into single-ended signal output, i.e., accurate amplification voltage signal.
As shown in Fig. 2, precision amplifier 21 includes amplifier INA322, first resistor R65, second resistance R66 and the first capacitance
The both ends of C47, first resistor R65 connect the pin RG0 and pin REF of amplifier INA322, the both ends point of second resistance R66 respectively
The both ends of the pin RG0 and pin VO, the first capacitance C47 that do not meet amplifier INA322 are grounded respectively and amplifier INA322 draws
Foot REF.The pin VO of amplifier INA322 is the output end of precision amplifier 21, exports accurate amplification voltage signal VO1.
Amplifier INA322 uses the instrument amplifier INA322 of TI, can increase in the Vcc3va operating at voltages of 2.7V
Benefit is set as 5 times minimum, and specific amplification factor is G=5（1+R66/R65）.It is 500kHz, 40 μ of power consumption in 5 times of gain lower band width
A.The pin REF of instrument amplifier INA322 is coupled to vcom=1/2Vcc3va, to lift the midpoint potential of voltage signal VO1
To 1/2Vcc.High-precision amplifying 21 send the amplified accurate voltage signal VO1 that amplifies to controllable amplifier 22.
The measurement range of the size and processor 3 of the voltage signal that controllable amplifier 22 is obtained according to probe 1, precision is put
The accurate amplification voltage signal that big device 21 amplifies is further amplified within the measurement dynamic range needed for processor 3, to obtain
Voltage amplification signal.The measurement range of processor 3 is determined by the A/D sample circuits in it.In use, controllable amplifier 22 is put
Big multiple can be arranged by processor 3.PGA can be used in controllable amplifier 22, but the noise of PGA, power consumption and cost are all higher.Cause
This, in practical applications, the combination of lower-cost analog switch and operational amplifier can be used in controllable amplifier 22.
As shown in figure 3, controllable amplifier 22 includes analog switch U11, operational amplifier U8A, low-pass filter circuit, the 4th
The positive input and output end of resistance R76 and the 5th resistance R77, operational amplifier U8A are respectively as controllable amplifier 22
Input terminal and output end, the pin NO of analog switch U11 connect the reverse input end of operational amplifier U8A, and low-pass filter circuit is set
Between the reverse input end and output end of operational amplifier U8A, the both ends of the 4th resistance R76 connect analog switch U11's respectively
Pin COM and ground；The both ends of 5th resistance R77 meet the control terminal IN and ground of analog switch U11 respectively.Low-pass filter circuit includes
Resistance R76 and the second capacitance C48, resistance R71 are in parallel with the second capacitance C48, resistance R71 be feedback resistance, the second capacitance C48 and
Resistance R71 forms low-pass filter circuit, high-frequency noise can be prevented to pass through.In use, resistance R76 and the second capacitance C48 are set
Between the reverse input end and output end of operational amplifier U8A.The homophase input of operational amplifier U8A terminates precision amplifier
21 output end, the output end of the output end of operational amplifier U8A as controllable amplifier 22, output voltage amplified signal VO2.
The present embodiment, analog switch U11 use TS5A3166.Analog switch U11 is combined with the 4th resistance R76 can form 2
The different resistance value of kind, forms the adjustable resistance part of controllable amplifier 22, and analog switch U11 and the 5th resistance R71 constitute 2 kinds
Different amplification factors.The resistance value of 4th resistance R76 selects 10k Ω, the resistance value of 3rd resistor R71 to select 100k Ω, the second capacitance C48
Capacitance select 10pF.
As shown in Figure 1, magnetic field measuring device further includes real effective unit comprising true effective value converting circuit 41, filter
Wave circuit 42 and real effective processing module（It is not shown in figure）.Wherein, true effective value converting circuit 41 is from controllable amplifier 22
Extraction and the voltage amplification signal corresponding to alternating compenent in tested magnetic field in the voltage amplification signal of output, and be converted into
Real effective voltage signal.Filter circuit 42 is for filtering real effective voltage signal, to filter out high frequency noise.At real effective
It manages module 43 and obtains the real effective for being tested magnetic field according to filtered real effective voltage signal.Real effective processing module 43
In processor 3, the part as processor 3.
Real effective circuit 41 can be built by discrete device, can be also calculated by DSP devices, consider power consumption,
Cost and debugging complexity consider that this example uses special integrated device.As shown in figure 4, true effective value converting circuit 41
Including the second analog switch U10 and third capacitance C49, the both ends of third capacitance C49 connect the input of the second analog switch U10 respectively
IN2 and ground, the size of third capacitance C49 is held to determine that the minimum frequency of input signal, third capacitance C49 use the capacitance of 0.1 μ F,
Second analog switch U10 uses the analog switch of Linear Tech model LT1968, bandwidth 800kHz.Second analog switch
The 5th foot VUT of U10 exports effective value signal vrms0.
As shown in figure 5, filter circuit 42 include second operational amplifier U12B, the 7th resistance R80, the 8th resistance R81 and
9th resistance R83, the 4th capacitance C52, the 5th capacitance C54 and the 6th capacitance C55.Wherein, one end ground connection of the 4th capacitance C52,
The 7th resistance R80 of the other end.7th resistance R80, the 8th resistance R81 and the 6th capacitance C55 cross into node A.7th resistance R80
One termination the 4th capacitance C52, another terminated nodes A.A terminated nodes A of 8th resistance R81, the second operation of another termination are put
The positive input of big device U12B.A terminated nodes A of 6th capacitance C55, another termination second operational amplifier U12B's is defeated
Outlet.The reverse input end of a termination second operational amplifier U12B of 9th resistance R83, another termination second operational amplifier
The output end of U12B.
Second operational amplifier U12B uses low consumed power operational amplifier, such as OPA2314, the 7th resistance in the present embodiment
R80 and the 8th resistance R81 is 10k, and it is 1uF that the 9th resistance R83, which is 20 Ω, the 4th capacitance C52 and the 6th capacitance C55, and the 5th
Capacitance C54 is 0.1uF.The output end output filtering of second operational amplifier U12B treated real effective voltage signal, and
Transmit it to processor 3.Processor 3 obtains the real effective for being tested magnetic field according to real effective voltage signal.
As shown in Figure 1, magnetic field measuring device further includes memory module 5, intensity, exchange for storing such as D.C. magnetic field
The characteristic in the tested magnetic field such as the intensity in magnetic field and the frequency of alternating current magnetic field and waveform, real effective and the magnetic in tested magnetic field
Field intensity measure some configuration, such as controllable amplifier 22 amplification factor.16Mbit can be used in the present embodiment memory module 5
FLASH memory.
Magnetic field measuring device further includes display unit 6, control unit 7 and power supply unit 8, and display unit 6 is all for showing
Such as the characteristic in the tested magnetic field of the frequency of the intensity of D.C. magnetic field, the intensity of alternating current magnetic field and alternating current magnetic field and tested magnetic field
Waveform.Control unit 7 is for the man-machine communication between operator and magnetic field measuring device.Power supply unit 8 is used to be magnetic-field measurement
Device provides electric energy.The present embodiment display unit 6 uses liquid crystal display device（Such as the Liquid Crystal Module of graphic dot matrix pattern）Or CRT
Display device；Control unit 7 uses button, button that can be set to liquid crystal display device.Display unit 6 and control unit 7 are constituted
Interpersonal interactive interface, flexibly to select the mode of operation of magnetic field measuring device and visually show measured result.Power supply unit 8
Using accumulator or AC power.Accumulator can be solar cell or lithium manganate battery, the LiMn2O4 electricity of such as 18650 types
Pond.
Magnetic field measuring device further includes charhing unit（It is not shown in figure）With Power Management Unit 9.Wherein, charhing unit is used
It charges in accumulator.Power Management Unit 9 such as controls accumulator and provides electric energy and control pair for controlling accumulator
Accumulator and rechargeable solar battery, to prevent the temperature of battery in over-pressed, overcurrent and charging process excessively high,.
Magnetic field measuring device further includes USB communication interfaces 10, USB communication interfaces 10 for make magnetic field measuring device with it is upper
Machine communicates, to transmit gathered data and configuration data；It can also be used to charge to accumulator.USB communication interfaces 10 can be used special
USB set is at chip, and the considerations of being in cost and circuit complexity, this example circuit is using the USB function modules inside processor.
The present embodiment processor 3 is used to be digitized processing to the amplified signal of controllable amplifier 22, and to filtering
The real effective voltage signal that the transmission of circuit 8 comes is digitized processing；And obtain the intensity of D.C. magnetic field, alternating current magnetic field it is strong
The temporal pattern of degree, the frequency of alternating current magnetic field and real effective, changes of magnetic field；It is then transmit to the display of display unit 6, or
Person is sent to host computer processing and is shown by USB communication interfaces 10.Processor 3 is additionally operable to control according to actual needs and controllably put
The amplification factor of big device 22, effectively to handle magnetic field signal.Processor 3 is additionally operable to be instructed according to the input of control unit 7,
Corresponding function is selected, signal is handled.Such as, after by 7 startup power supply unit 8 of control unit, processor 3 draws high Pwron_
430, into normal operating conditions, power supply unit 8 is made to keep power supply；When magnetic field measuring device is in leisure state, processor 3
Pwron_430 is dragged down, power supply unit 8 is made to stop power supply, this control mode can save the energy, reduce power consumption.Processor 3 is also
It is shown on display unit 6 for the voltage of periodic sample battery, and by the electricity of accumulator, when the electricity of accumulator
User's charging is reminded when too low.Various types of MCU can be used in processor 3, but need to ensure the internal ADC for having 2 12 or more,
Sampling rate is in 1Msps or more.Considering cost and power consumption, the model that the present embodiment processor 3 is produced using ST companies
STM32L151R8T6 processors, are internally provided with ADC, low in energy consumption, noise is low, and can flicker free adjustment liquid-crystal apparatus
Backlight illumination.
The GMR magnetic that magnetic field measuring device provided in this embodiment utilizes the giant magnetoresistive thin film with giant magnetoresistance effect to be formed passes
Sensor is probe, and the range of dynamic measurement of GMR Magnetic Sensors is up to 80dB, and bandwidth is up to 2MHz, and high sensitivity, cost
It is low.
It is understood that the principle that embodiment of above is intended to be merely illustrative of the present and the exemplary implementation that uses
Mode, however the present invention is not limited thereto.For those skilled in the art, in the essence for not departing from the present invention
In the case of refreshing and essence, various changes and modifications can be made therein, these variations and modifications are also considered as protection scope of the present invention.
Claims (11)
1. a kind of magnetic field measuring device, including：
Probe, for incuding tested magnetic field and obtaining voltage signal；
Amplifier obtains voltage amplification signal for amplifying the voltage signal；The amplifier includes precision amplifier,
For amplifying the voltage signal, to obtain accurate amplification voltage signal；
Processor, the wave of characteristic and the tested magnetic field for obtaining the tested magnetic field according to the voltage amplification signal
Shape；
It is characterized in that, the GMR Magnetic Sensors that the probe is formed using the giant magnetoresistive thin film with giant magnetoresistance effect, the essence
Close amplifier includes amplifier INA322, first resistor R65, second resistance R66 and the first capacitance C47, the first resistor
The both ends of R65 meet the pin RG0 of the amplifier INA322 respectively and pin REF, the both ends of the second resistance R66 connect respectively
The pin RG0 of the amplifier INA322 and the both ends of pin VO, the first capacitance C47 are grounded respectively and the amplifier
The pin REF of INA322.
2. magnetic field measuring device according to claim 1, which is characterized in that the characteristic in the tested magnetic field includes D.C. magnetic field
Intensity, the frequency of the intensity of alternating current magnetic field and alternating current magnetic field.
3. magnetic field measuring device according to claim 1, which is characterized in that the amplifier includes controllable amplifier, is used
Within the measurement dynamic range that the accurate amplification voltage signal is further amplified needed for the processor, to obtain
State voltage amplification signal；
The controllable amplifier includes：Analog switch U11, operational amplifier U8A, low-pass filter circuit, the 4th resistance R76 and
Input terminal of the positive input and output end of five resistance R77, the operational amplifier U8A respectively as the controllable amplifier
And output end, the pin NO of the analog switch U11 connect the reverse input end of the operational amplifier U8A, the low-pass filtering
Between the reverse input end and output end of the operational amplifier U8A, the both ends of the 4th resistance R76 connect circuit respectively
The pin COM and ground of the analog switch U11；The both ends of the 5th resistance R77 connect the control of the analog switch U11 respectively
Hold IN and ground.
4. magnetic field measuring device according to claim 1, which is characterized in that further include real effective unit comprising：
True effective value converting circuit is used for from extraction in the voltage amplification signal and alternating compenent institute in the tested magnetic field
Corresponding voltage amplification signal, and it is converted into real effective voltage signal；
Filter circuit is used to filter the real effective voltage signal, to filter out high frequency noise；
Real effective processing module, obtaining the true of the tested magnetic field according to the filtered real effective voltage signal has
Valid value.
5. magnetic field measuring device according to claim 4, which is characterized in that the true effective value converting circuit includes the second mould
Quasi- switch U10 and third capacitance C49, the both ends of the third capacitance C49 connect the input terminal of the second analog switch U10 respectively
IN2 and ground, the third capacitance C49 use the capacitance of 0.1 μ F, the second analog switch U10 to use Linear Tech's model
The analog switch of LT1968.
6. magnetic field measuring device according to claim 4, which is characterized in that further include memory module, for storing tested magnetic
The characteristic of field, the waveform in the tested magnetic field and the real effective.
7. magnetic field measuring device according to claim 1, which is characterized in that further include：
Display unit, the waveform of characteristic and the tested magnetic field for showing the tested magnetic field；
Control unit, for the man-machine communication between operator and magnetic field measuring device；
Power supply unit, for providing electric energy for magnetic field measuring device.
8. magnetic field measuring device according to claim 7, which is characterized in that the display unit be liquid crystal display device or
CRT display devices.
9. magnetic field measuring device according to claim 7, which is characterized in that the power supply unit is accumulator or alternating current
Source.
10. magnetic field measuring device according to claim 9, which is characterized in that further include：
Charhing unit, for charging to the accumulator；
Power Management Unit provides electric energy and the control accumulator charging for controlling the accumulator.
11. magnetic field measuring device according to claim 1, which is characterized in that further include：
USB communication interfaces, for being communicated between magnetic field measuring device and host computer.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201310286665.9A CN104280698B (en) | 2013-07-09 | 2013-07-09 | Magnetic field measuring device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201310286665.9A CN104280698B (en) | 2013-07-09 | 2013-07-09 | Magnetic field measuring device |
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| CN104280698A CN104280698A (en) | 2015-01-14 |
| CN104280698B true CN104280698B (en) | 2018-09-28 |
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| CN201310286665.9A Expired - Fee Related CN104280698B (en) | 2013-07-09 | 2013-07-09 | Magnetic field measuring device |
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Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105785289A (en) * | 2016-05-22 | 2016-07-20 | 南宁市茂百科技有限公司 | Portable magnetic-field detector |
| CN109932668B (en) * | 2019-03-27 | 2020-11-27 | 三峡大学 | Forward and reverse excitation-based low hysteresis TMR magnetic field measuring device |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1794003A (en) * | 2005-11-02 | 2006-06-28 | 吉林大学珠海学院 | Strong magnetic impedance magnetic field sensor |
| CN101438180A (en) * | 2006-05-10 | 2009-05-20 | 皇家飞利浦电子股份有限公司 | Magneto-resistive sensors with improved output signal characteristics |
| CN201917649U (en) * | 2010-09-26 | 2011-08-03 | 北京鼎臣超导科技有限公司 | Magnetic sensor base on giant magneto-impedance (GMI) |
| CN202066953U (en) * | 2011-05-30 | 2011-12-07 | 北京鼎臣超导科技有限公司 | Magnetic sensor |
| CN202614920U (en) * | 2012-07-03 | 2012-12-19 | 北京航空航天大学 | Magnetic sensor based on giant magneto-impedance phase response |
| CN203350428U (en) * | 2013-07-09 | 2013-12-18 | 北京嘉岳同乐极电子有限公司 | Magnetic field measurement apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4424093B2 (en) * | 2004-06-28 | 2010-03-03 | ヤマハ株式会社 | Magnetic sensor |
-
2013
- 2013-07-09 CN CN201310286665.9A patent/CN104280698B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1794003A (en) * | 2005-11-02 | 2006-06-28 | 吉林大学珠海学院 | Strong magnetic impedance magnetic field sensor |
| CN101438180A (en) * | 2006-05-10 | 2009-05-20 | 皇家飞利浦电子股份有限公司 | Magneto-resistive sensors with improved output signal characteristics |
| CN201917649U (en) * | 2010-09-26 | 2011-08-03 | 北京鼎臣超导科技有限公司 | Magnetic sensor base on giant magneto-impedance (GMI) |
| CN202066953U (en) * | 2011-05-30 | 2011-12-07 | 北京鼎臣超导科技有限公司 | Magnetic sensor |
| CN202614920U (en) * | 2012-07-03 | 2012-12-19 | 北京航空航天大学 | Magnetic sensor based on giant magneto-impedance phase response |
| CN203350428U (en) * | 2013-07-09 | 2013-12-18 | 北京嘉岳同乐极电子有限公司 | Magnetic field measurement apparatus |
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