CN104520722A - High-precision cross-core closed-loop single power supply electronic circuit for hall current sensor - Google Patents
High-precision cross-core closed-loop single power supply electronic circuit for hall current sensor Download PDFInfo
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- CN104520722A CN104520722A CN201280056670.4A CN201280056670A CN104520722A CN 104520722 A CN104520722 A CN 104520722A CN 201280056670 A CN201280056670 A CN 201280056670A CN 104520722 A CN104520722 A CN 104520722A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
- G01R15/202—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices using Hall-effect devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/003—Measuring mean values of current or voltage during a given time interval
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Measuring Magnetic Variables (AREA)
- Hall/Mr Elements (AREA)
Abstract
A high-precision cross-core closed-loop single power supply electronic circuit for a Hall current sensor belongs to the field of electronic circuitry for a Hall current sensor. A current to be measured less than 50 A is output using a heavy current, and one of rail-to-rail input/output dual operational amplifiers (1/2A1) amplifies the output voltages of Hall elements (H1, H2) to drive a secondary coil (NS), and the other amplifier is used as an I/V converter; a current to be measured greater than 50 A is output using a heavy current, and one of rail-to-rail output dual operational amplifiers (1/2A1) amplifies the output voltages of Hall elements (H1, H2) to form an H-bridge with the other amplifier so as to drive the secondary coil (NS); a secondary current (IS) is sampled and then differential amplification output is performed thereon using a rail-to-rail input/output dual operational amplifier (1/2A2); variable voltage references (VZ1, VZ2) are used to offset the amplifiers and Hall elements; a reference voltage end (VR) can both output and externally control changes; and a plurality of Hall elements use a constant voltage operation mode to calculate the arithmetic mean value of the output voltages thereof. The Hall current sensor has a larger measurement range and higher precision.
Description
The present invention relates to Hall current sensor field of electronic circuitry, more particularly to a kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit with single supply electronic circuit technology field for core-theaded type high precision closed loop type Hall current sensor.Background technology is said
Current sensor is a kind of quite varied electronic building brick of application, and it is widely used in various Semiconductor Converting Technologies, is exchanged in the automatic control field using electric current as control object such as numerical control device.
Many to the non-cpntact measurement and monitoring method of electric current, Hall current sensor forms industrialization because being widely used its excellent cost performance；Hall current sensor generally has open loop, two kinds of Working mould books of closed loop
Formula, closed-loop type Hall current sensor is made up of the toroidal core being made of soft magnetic materials, Hall element, secondary coil and appropriate power amplification circuit, Hall element plays nulling device herein, therefore the higher the better for its sensitivity, the general high sensitivity Hall element for selecting InSb materials to make, its correlation properties is as shown in figure one, figure two.
In recent years, with the high speed development of Power Electronic Technique, various new technologies, new product make rapid progress in the automatic control field using electric current as control object such as various Semiconductor Converting Technologies, exchange numerical control device, its core component MCU or DSP integrated level is increasing, volume is less and less, for reduction power consumption, its working power voltage is more and more lower, and single supply closed-loop type Hall current sensor matches because of the requirement of its power supply, output voltage amplitude and its core component MCU or DSP, other interface circuits are no longer needed, therefore are gained great popularity.External single supply closed-loop type Hall current sensor typically uses special completely inegrated circuit（ASIC), make the electronic component quantity of sensor few, be easy to batch production, this electronic line structure has problems with：
1st, special completely inegrated circuit（ASIC Hall element) must be made using silicon single crystal, and the sensitivity of silicon Hall element is low, temperature drift is big, thus the current sensor made of it is big to the error of current measurement, operating temperature range is narrow, limits the scope of application of current sensor.
2nd, for the current measurement range of different measurement ranges, special completely inegrated circuit（ASIC it is) poor for applicability, only it is applicable small electric flow measurement application within 25A.In larger electric current（More than 50A）When, give
1
Confirm this
The limitation of fixed physical dimension, secondary coil coiling size is certain, and coil turn and line footpath size are also restricted, and coil turn is more, then the line footpath of coil is small, internal resistance is big, thus can not realize under single supply condition of work the measurement of larger current.
3rd, this circuit is typically applied in the full PCB installing types closed-loop type Hall current sensor of single supply, it is difficult to realize the core-theaded type high-acruracy survey of the electric current under single supply condition of work.
The content of the invention
In order to solve the above-mentioned technical problem, it is an object of the invention to provide a kind of measurement range higher core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit of big, precision.The present invention complete skill scheme be, a kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit：
To 5 below OA electric current High-current outputs to be measured, rail-to-rail (ra i l to ra i l) input/output dual operational amplifier one by the output voltage of Hall element amplification driving secondary coil, another amplifier is used as I/V converters；Amplifier, Hall element are biased with variable voltage benchmark；Reference voltage end is exportable and external control changes；Multiple Hall elements seek arithmetic mean of instantaneous value using constant pressure mode of operation to its output voltage.
To more than 50A electric current High-current outputs to be measured, rail-to-rail（Ra i l to ra i l) amplification of the output voltage of Hall element and another amplifier constitute H bridges and drive secondary coil by the dual operational amplifier one of output；Rail-to-rail is used after being sampled to secondary current（Ra i l to ra i l) input/output dual operational amplifier carry out differential amplification output；Amplifier, Hall element are biased with variable voltage benchmark；Reference voltage end is exportable and can external control change；Multiple Hall elements seek arithmetic mean of instantaneous value using constant pressure mode of operation to its output voltage.
The reference voltage part is made reference voltage and output amplifier is biased using 1. 25V or 2. 5V variable voltage benchmark, and Hall element is biased using 1. 25V variable voltage benchmark.
The sample resistance is using 0603 encapsulation, 0. 1% 25ppm/ °C of precision chip resistor.
The reference voltage end be it is exportable and can external control change part be provided with one adjustment resistance, the adjustment resistance be 200-680 ohm.
Therefore, it is of the invention to be had the advantages that compared with present technology：
1st, High-current output, rail-to-rail are used to 5 below OA electric currents to be measured（Rail to rail) input/output dual operational amplifier is by the output voltage of Hall element amplification driving secondary coil and realizes that I/V is converted, make that the circuit structure of current sensor is very simple and output voltage range reaches rail-to-rail（Rail to rail), its current measuring range reaches more than 3 times of rated current（Fig. 3).
2nd, the dual operational amplifier exported to 50 more than Λ electric currents to be measured using High-current output, rail-to-rail (rail to rail) is amplified the output voltage of Hall element and composition H bridges drive secondary coil；Differential amplification output is carried out with the dual operational amplifier of rail-to-rail (rail to rail) input/output after being sampled with sample resistance to secondary current, the output voltage range of current sensor is reached rail-to-rail（Rail to rail), its rated current measured at least adds one times under the conditions of same core structure, identical coil line footpath and the number of turn compared with figure three, thus its current measuring range also at least adds more than one times.
3rd, sample resistance makes the temperature drift of the output voltage of current sensor also reach 25ppm/ °C using 0603 encapsulation, 0.1% 25ppm/ °C of precision chip resistor.
4th, reference voltage is made using 1.25V or 2.5V variable voltage benchmark, adjustment resistance takes 200-680 ohm, reference voltage end be it is exportable and can external control change, make the current sensor scope of application wider.
5th, it is biased using 1.25V variable voltage benchmark as Hall element, Hall element is in constant pressure mode of operation.In both the above circuit, the output end of Hall element is asked after arithmetic mean of instantaneous value, and the output unbalance voltage of N number of Hall element and temperature drift, noise voltage etc. are declined by ^ ^ times, make the measurement lower limit of sensor lower.Its zero point output is 100 ppm/.Within C, operation temperature area reaches -40 ~ 85 °C.
6th, the core-theaded type high-precision hall closed-loop type Hall current sensor of another patent one applied using inventor is coordinated with coaxial double loop magnetic core coil component and both the above circuit, make to realize under single supply condition of work and treat side electric current core-theaded type high-acruracy survey, measurement accuracy is reached within 0.2%FS.
Brief description of the drawings
Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the part of the application, does not constitute inappropriate limitation of the present invention, in the accompanying drawings：
Fig. 1 is the temperature characterisitic of the unbalance voltage of InSb Hall elements；
Fig. 1 is the temperature characterisitic of the output voltage of InSb Hall elements；
Fig. 3 is 50 below Λ core-theaded type high precision closed loop type Hall current sensor single supply circuit diagrams；
Fig. 4 is more than 50A core-theaded type high precision closed loop type Hall current sensor single supply circuit block diagrams；Fig. 5 is more than 50A core-theaded type high precision closed loop type Hall current sensor single supply circuit diagrams.Embodiment
Describe the present invention in detail below in conjunction with accompanying drawing and specific embodiment, illustrative examples of the invention and explanation are used for explaining the present invention herein, but not as a limitation of the invention.Embodiment 1:
A kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit of the present embodiment, to 5 below OA electric currents to be measured are using High-current output, the dual operational amplifier TS922 driving secondary coils of rail-to-rail (ra i l to ra i l) input/output and realize that I/V is converted, amplifier, Hall element are biased with variable voltage benchmark；Reference voltage end is exportable and external control changes；Multiple Hall elements seek arithmetic mean of instantaneous value using constant pressure mode of operation to its output voltage.Reference voltage part reference voltage is made using AZ431-2. 5V voltage references, Hall element is biased using AZ432-1. 25V voltage references, Hall element is set to be in constant pressure mode of operation, sample resistance is using 0603 encapsulation, 0. 1% 25ppm/ °C of precision chip resistor, reference voltage terminal is exportable and external control changes, reference voltage part is provided with an adjustment resistance, and adjustment resistance is 680 ohm of 200-.
Embodiment 2:
A kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit of the present embodiment, constitutes H bridges to the dual operational amplifier GM8923 that 5 more than OA electric currents to be measured are exported using High-current output, rail-to-rail (ra i l to ra i l) and drives secondary coil and rail-to-rail（Ra i l to ra i l) input/output dual operational amplifier TS922 carry out differential amplification output, amplifier, Hall element are biased with variable voltage benchmark；Reference voltage end is exportable and external control changes；Multiple Hall elements seek arithmetic mean of instantaneous value using constant pressure mode of operation to its output voltage.Reference voltage is made in reference voltage part using AZ431-2. 5V voltage references, and Hall element is biased using the 25V voltage references of AZ432- 1., Hall element is in constant pressure mode of operation, and sample resistance is using 0603 encapsulation, 0. 1% 25PPm/ °C of precision chip resistor, reference voltage terminal is exportable and external control changes, and reference voltage part is provided with an adjustment resistance, and adjustment resistance is 200-680 ohm.
Therefore,
1st, secondary coil is driven using the dual operational amplifier TS922 of High-current output, rail-to-rail (rail to rail) input/output to 50 below Λ electric currents to be measured and realizes that I/V is converted, make that the circuit structure of current sensor is very simple and output voltage range reaches rail-to-rail（Rail to rail), its current measuring range reaches more than 3 times of rated current.
2nd, High-current output, rail-to-rail are used to 5 more than OA electric currents to be measured（Rail to rail) output dual operational amplifier GM8923 composition H bridges driving secondary coils；TS922 rail-to-rails are used after being sampled with sample resistance to secondary current（Rail to rail) input/output dual operational amplifier carry out differential amplification output, the output voltage range of current sensor is reached rail-to-rail（Rail to rail), its rated current measured at least adds one times under the conditions of same core structure, identical coil line footpath and the number of turn compared with figure three, thus its current measuring range also at least adds more than one times.
3rd, sample resistance is using 0603 encapsulation, 0.1% 25pptn/ °C of precision chip resistor, make the output voltage of current sensor temperature drift also reach 25ppm/ ° (.
4th, reference voltage is made using AZ431-2.5V voltage references, adjustment resistance takes 200-680 ohm, reference voltage end be it is exportable and can external control change, make the current sensor scope of application wider.
5th, it is biased using AZ432-1.25V voltage references as Hall element, Hall element is in constant pressure mode of operation.In both the above circuit, the output end of Hall element is asked after arithmetic mean of instantaneous value, and the output unbalance voltage of N number of Hall element and temperature drift, noise voltage etc. are declined by ^ ^ times, make the measurement lower limit of sensor lower.Its zero point output be 100ppm/ °C within, operation temperature area reach-40-85 ° (：.
6th, the core-theaded type high-precision hall closed-loop type Hall current sensor of another patent one applied using inventor is coordinated with coaxial double loop magnetic core coil component and both the above circuit, single supply work how is realized under part and treat side electric current core-theaded type high-acruracy survey, measurement accuracy is reached within 0.2%FS.
The technical scheme provided above the embodiment of the present invention is described in detail, used herein bright to be only applicable to help the principle for understanding the embodiment of the present invention；Simultaneously for the general technology people of this area
Member, according to the embodiment of the present invention, will change, in summary, this specification content should not be construed as limiting the invention in embodiment and application.
Claims (2)
- Claims1st, a kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit, it is characterised in that：To 5 below OA electric current High-current outputs to be measured, rail-to-rail (ra i l to ra i l) input/output dual operational amplifier one by the output voltage of Hall element amplification driving secondary coil, another amplifier is used as I/V converters；Amplifier, Hall element are biased with variable voltage benchmark；Reference voltage end is exportable and external control changes；Multiple Hall elements seek arithmetic mean of instantaneous value using constant pressure mode of operation to its output voltage.To 5 more than OA electric current High-current outputs to be measured, rail-to-rail（The r a i 1 of ra i 1 10) amplification of the output voltage of Hall element and another amplifier constitute H bridges and drive secondary coil by the dual operational amplifier one of output；Rail-to-rail is used after being sampled to secondary current（Ra i l to ra i l) input/output dual operational amplifier carry out differential amplification output；Amplifier, Hall element are biased with variable voltage benchmark；Reference voltage end is exportable and can external control change；Multiple Hall elements seek arithmetic mean of instantaneous value using constant pressure mode of operation to its output voltage.2nd, a kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit according to claim 1, it is characterized in that, make reference voltage using 1. 25V or 2. 5V variable voltage benchmark and output amplifier is biased in the reference voltage part,, Hall element is biased using 1. 25V variable voltage benchmark.3rd, a kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit according to claim 1, it is characterised in that the sample resistance is using 0603 encapsulation, 0. 1 °/25ppm/ °C of precision chip resistor.4th, a kind of core-theaded type high precision closed loop type Hall current sensor single supply electronic circuit according to claim 1, it is characterized in that, the reference voltage end be it is exportable and can external control change part be provided with one adjustment resistance, the adjustment resistance be 200-680 ohm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201280056670.4A CN104520722A (en) | 2012-01-19 | 2012-02-09 | High-precision cross-core closed-loop single power supply electronic circuit for hall current sensor |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012200260429 | 2012-01-19 | ||
| CN 201220026042 CN202583289U (en) | 2012-01-19 | 2012-01-19 | A single-power-supply electronic circuit used for a passing through high-precision closed loop Hall current sensor |
| PCT/CN2012/000157 WO2013106961A1 (en) | 2012-01-19 | 2012-02-09 | High-precision cross-core closed-loop single power supply electronic circuit for hall current sensor |
| CN201280056670.4A CN104520722A (en) | 2012-01-19 | 2012-02-09 | High-precision cross-core closed-loop single power supply electronic circuit for hall current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104520722A true CN104520722A (en) | 2015-04-15 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201220026042 Expired - Lifetime CN202583289U (en) | 2012-01-19 | 2012-01-19 | A single-power-supply electronic circuit used for a passing through high-precision closed loop Hall current sensor |
| CN201280056670.4A Pending CN104520722A (en) | 2012-01-19 | 2012-02-09 | High-precision cross-core closed-loop single power supply electronic circuit for hall current sensor |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201220026042 Expired - Lifetime CN202583289U (en) | 2012-01-19 | 2012-01-19 | A single-power-supply electronic circuit used for a passing through high-precision closed loop Hall current sensor |
Country Status (2)
| Country | Link |
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| CN (2) | CN202583289U (en) |
| WO (1) | WO2013106961A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112834800A (en) * | 2021-01-07 | 2021-05-25 | 四川众航电子科技有限公司 | Single-power-supply Hall sensor device |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202583289U (en) * | 2012-01-19 | 2012-12-05 | 邹高芝 | A single-power-supply electronic circuit used for a passing through high-precision closed loop Hall current sensor |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2099979U (en) * | 1991-07-17 | 1992-03-25 | 机械电子工业部第五八研究所 | Photoelectric coupled micro-electric quantity sensor |
| JPH05119077A (en) * | 1991-10-24 | 1993-05-14 | Tokin Corp | Current detector |
| JPH0886813A (en) * | 1994-09-19 | 1996-04-02 | Yazaki Corp | Detection circuit of non-contact type sensor |
| CN2689241Y (en) * | 2004-04-26 | 2005-03-30 | 邹高芝 | Single-power supply circuit of current and voltage sensor |
| JP2006038834A (en) * | 2004-06-21 | 2006-02-09 | Tdk Corp | Current sensor |
| CN101876671A (en) * | 2009-12-12 | 2010-11-03 | 杭州日鼎控制技术有限公司 | High-precision current sampling circuit used in servo system |
| CN102279305A (en) * | 2011-04-13 | 2011-12-14 | 大连丰和电力科技有限公司 | Closed loop magnetic balance type Hall current sensor |
| CN102298084A (en) * | 2010-06-24 | 2011-12-28 | 胜美达集团株式会社 | Current sensor |
| CN202583289U (en) * | 2012-01-19 | 2012-12-05 | 邹高芝 | A single-power-supply electronic circuit used for a passing through high-precision closed loop Hall current sensor |
-
2012
- 2012-01-19 CN CN 201220026042 patent/CN202583289U/en not_active Expired - Lifetime
- 2012-02-09 WO PCT/CN2012/000157 patent/WO2013106961A1/en active Application Filing
- 2012-02-09 CN CN201280056670.4A patent/CN104520722A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2099979U (en) * | 1991-07-17 | 1992-03-25 | 机械电子工业部第五八研究所 | Photoelectric coupled micro-electric quantity sensor |
| JPH05119077A (en) * | 1991-10-24 | 1993-05-14 | Tokin Corp | Current detector |
| JPH0886813A (en) * | 1994-09-19 | 1996-04-02 | Yazaki Corp | Detection circuit of non-contact type sensor |
| CN2689241Y (en) * | 2004-04-26 | 2005-03-30 | 邹高芝 | Single-power supply circuit of current and voltage sensor |
| JP2006038834A (en) * | 2004-06-21 | 2006-02-09 | Tdk Corp | Current sensor |
| CN101876671A (en) * | 2009-12-12 | 2010-11-03 | 杭州日鼎控制技术有限公司 | High-precision current sampling circuit used in servo system |
| CN102298084A (en) * | 2010-06-24 | 2011-12-28 | 胜美达集团株式会社 | Current sensor |
| CN102279305A (en) * | 2011-04-13 | 2011-12-14 | 大连丰和电力科技有限公司 | Closed loop magnetic balance type Hall current sensor |
| CN202583289U (en) * | 2012-01-19 | 2012-12-05 | 邹高芝 | A single-power-supply electronic circuit used for a passing through high-precision closed loop Hall current sensor |
Non-Patent Citations (2)
| Title |
|---|
| 李泽勇 等: "20kA闭环霍尔电流传感器在核聚变装置供电电源系统中的应用", 《电源世界》 * |
| 李泽勇 等: "闭环霍尔电流传感器在车用电源系统中的应用", 《电子元器件应用》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112834800A (en) * | 2021-01-07 | 2021-05-25 | 四川众航电子科技有限公司 | Single-power-supply Hall sensor device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN202583289U (en) | 2012-12-05 |
| WO2013106961A1 (en) | 2013-07-25 |
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