WO2013106959A1

WO2013106959A1 - High-precision whole pcb-mounted closed-loop axisymmetric magnetic circuit magnetic core coil component for hall current sensor

Info

Publication number: WO2013106959A1
Application number: PCT/CN2012/000155
Authority: WO
Inventors: 邹高芝
Original assignee: Zou Gaozhi
Priority date: 2012-01-19
Filing date: 2012-02-09
Publication date: 2013-07-25
Also published as: CN202711934U; CN104520723A

Abstract

A closed-loop axisymmetric magnetic circuit magnetic core coil component for a Hall current sensor includes two skeletons, a magnetic core and coil windings. The skeletons include an inner skeleton and an outer skeleton, wherein the inner skeleton is wound with a secondary coil winding, and the outer skeleton is wound with a primary coil winding. The inner skeleton and the outer skeleton are inserted towards and locked by each other, and a magnetic core slot and jack are provided on the skeletons. A magnetic core is formed by inserting multiple layers of riveting magnetic sheets with different widths towards each other. The magnetic core is of an axisymmetric magnetic circuit structure, and a single air gap is located at the end of the axis of symmetry near the magnetic core, with Hall elements being provided within the air gap. The magnetic core is mounted in the magnetic core slot and jack of the skeletons, and coil windings on the inner and outer skeletons are located on the axis of symmetry of the magnetic core, and the magnetic core coil component is mounted on a printed circuit board. The magnetic core coil component is of a simple structure, is convenient to mount and is of high precision.

Description

Full PCB mounted high precision closed loop Hall current sensor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of magnetic core coil assemblies for current sensors, and more particularly to an axially symmetric magnetic circuit core coil assembly for a full-PCB mounted high-precision closed-loop Hall current sensor. Background technique

The current sensor is a widely used electronic component, and it is widely used in various fields of current control, such as various current conversion technologies and AC numerical control devices.

There are many methods for non-contact measurement and monitoring of current. Hall current sensors are industrialized due to their excellent price/performance ratio. Full PCB mounted Hall current sensors are generally used for measuring and monitoring currents below 5 OA. Hall current sensors usually have open-loop and closed-loop modes. The two-mode full-PCB-mounted current sensors generally use a single air gap and a single chip laminated ring magnetic circuit structure (see Figure 1). The current sensor of the magnetic circuit structure has the following problems:

1. The full PCB-mounted open-loop Hall current sensor has a small number of current ampere-turns. To increase the current ampere-turns, the primary must be wound in multiple turns, that is, wound on a single air gap, single-chip laminated toroidal core. Multi-turn coil; In order to ensure the output amplitude of the sensor, the circuit amplification factor is large, and the zero point and amplitude of the sensor are repeatedly debugged, making the open-loop Hall current sensor production efficiency too low, and high-efficiency mass production cannot be realized. The 5% FS, the precision of the current is determined by the magnetic field of the current sensor is too large (see Figure 2), which seriously affects the accuracy of the small current measurement, in the measurement range of 3 times the rated current, the accuracy is preferably 1. 5% FS, Small signal bandwidth can only be achieved from 0 to 50KHZ.

2. The fully-mounted closed-loop Hall current sensor is mass-produced by inserting the toroidal core structure and the primary and secondary coils separately, but the lead end of the primary coarse coil is not easy to be accurately mounted and fixed. Mass production efficiency; and the cross section of the punched laminated core is square, plus the sheath, the coil path is long, the internal resistance is large, the linear measurement range of the sensor is small, and the anti-saturation ability is poor; Resistance, thicker wire diameter, which increases the volume and weight of the sensor, is not conducive to sensing

1

Confirmation The miniaturization of the device consumes more copper and increases the cost of the sensor. This structure does not fundamentally solve the problem of remanence of the magnetic core. In particular, many control systems lag behind the monitored current in the time, that is, the first There is monitoring current and then the sensor power supply. In this case, the remanence of the core is more prominent, and the remanence of the core increases with time (see Figure 2). The measurement range is 2 times the rated current, and the accuracy is preferably 1. 0%FS, - 3db bandwidth is 0-100KHZ.

Summary of the invention

In order to solve the above technical problems, an object of the present invention is to provide an axisymmetric magnetic circuit core coil assembly for a full- PCB mounted high-precision closed-loop Hall current sensor having a simple structure, a convenient mounting, and a higher precision. The complete technical solution of the present invention is a novel axisymmetric magnetic circuit core coil assembly, comprising two skeletons and a magnetic core and a coil winding, wherein the skeleton is an inner skeleton and an outer skeleton, respectively, and the inner skeleton is wound a secondary coil winding, the outer bobbin is wound with a primary coil winding, the inner bobbin is interlocked with the outer bobbin, and the core is provided with a magnetic core slot and a jack;

The magnetic core comprises a pair of different punch width multi-layer riveting magnetic pieces, the magnetic core is an axisymmetric magnetic circuit structure, and a single air gap is located on the axis of symmetry near the end of the magnetic core; the magnetic core is installed at a magnetic core slot and a socket in the skeleton; a Hall element is disposed in the air gap;

The coil windings on the inner and outer bobbins are located on the axis of symmetry of the magnetic core;

The core coil assembly is mounted on a sensor printed circuit board.

A fixed grounding pinhole is left in the center of the magnetic core insertion portion, and a pin is disposed in the fixed grounding pinhole, and the pin is connected to the ground wire of the printed circuit board through the magnetic core grounding pinhole.

The number of layers of the multi-layer interposing structure magnetic core of the punch is singular (7, 9, 11...).

The uppermost and lowermost layers of the magnetic core have a width smaller than that of the intermediate layer axial core. —

The magnetic core insertion hole on the inner bobbin is a chamfered magnetic core insertion hole, and the inner skeleton chamfer size corresponds to an angle formed by the upper magnetic piece of the magnetic core axis magnetic piece and the intermediate magnetic piece; The outer skeleton chamfer size matches the inner skeleton chamfer size.

The inner bone is close to the distal end and has a size matching with the 3:1 element and a magnetic core gap with the symmetry axis The through slots and the secondary coil end pin mounting slots are left.

The upper end of the end baffle of the outer bobbin is provided with a primary winding end fixing groove hole of different sizes, and the lower end is provided with an outer frame fixing pin mounting slot, the protruding post on the outer cover plate and the outer frame The fixing groove holes are tightly fitted. The magnetic core slot on the outer bobbin has a magnetic core grounding wire isolation plate.

The inner and outer skeletons, the outer casing and the cover plate are all injection molded from polyphenylene sulfide (PPS) high temperature resistant plastic. As can be seen from the above, the present invention has the following beneficial effects as compared with the prior art:

1. The axisymmetric magnetic circuit structure of the invention and a single air gap on the axis of symmetry eliminates the influence of magnetic core remanence and electromagnetic interference, so that the accuracy and anti-interference ability of the current sensor are greatly improved, and the small current measurement accuracy is improved. It is within 0.2% FS.

2. The multi-layered magnetic core and the chamfered skeleton are matched with different punch widths, so that the coil path is short, the internal resistance is small, and the sensor is linearly measured under the same wire diameter and the same number of turns in the secondary winding area. The range is large; the electromagnetic isolation and coupling are formed by the inner and outer skeletons of the primary winding and the primary winding, respectively; the electronic circuit related to the applicant's other patent application is used together, so that the measuring range of the sensor reaches 3 times of the rated Current, response time is less than 1. 0uS, -3db bandwidth is above 0-100KHZ.

3. The primary coil end of the outer frame is fixed and the groove is tightly matched with the outer cover plate and the anti-climbing structure with the magnetic core grounding plate is used to improve the insulation strength, and the insulation voltage reaches 5KV or more.

4, the structure is simple, easy to manufacture. The skeleton is mass-produced by injection molds; the primary and secondary coils are prefabricated by the inner and outer skeletons, the anti-locking and the skeleton structure with the fixing holes of the primary and secondary coil ends, and the primary and secondary coil ends are assembled firmly and conveniently.

5. The Hall element is installed in the air gap slot to ensure that the sensitive center of the Hall element is always located at the geometric center of the core air gap, and the installation consistency is good, thus ensuring the performance consistency of the sensor.

6. It is convenient to connect with the printed circuit board and small in size. The primary and secondary coils can be pre-customized according to the rated current; the primary winding ends are immersed in tin and pass through the primary fixing holes on the skeleton; the ends of the secondary winding are respectively hooked around the secondary end fixing slots of the press-in frame On the lead pin, after the immersion tin, the inner and outer skeletons are inserted and locked, and the magnetic core is installed, so that the magnetic core coil assembly of the integral structure can be mounted on the sensor circuit board as a lead electronic component. Self-mixing process with SMD Dynamic mass production, while miniaturizing current sensors.

DRAWINGS

The drawings described herein are provided to provide a further understanding of the invention, and constitute a part of this application.

Figure 1 shows the magnetic field distribution of a single-loop magnetic core;

Figure 2 shows the residual magnetic field distribution of a single-loop magnetic core;

Figure 3 is a magnetic field distribution of the axisymmetric loop core;

Figure 4 shows the residual magnetic field distribution of the axisymmetric loop core.

detailed description

The invention is described in detail below with reference to the accompanying drawings and specific embodiments. Example 1:

In this embodiment, an axisymmetric magnetic circuit core coil assembly for a full-PCB mounted closed-loop Hall current sensor includes two skeletons and a magnetic core and a coil winding, and the skeleton is an inner skeleton and an outer skeleton, respectively. The inner bobbin is wound with a secondary winding, the outer bobbin is wound with a primary coil winding, the inner bobbin is interlocked with the outer bobbin, and the core is provided with a magnetic core slot and a jack; The core is formed by inserting multiple layers of riveted magnetic sheets with different punch widths. The number of layers of the multi-layer interposing structure core is generally singular, such as 7, 9, 11 layers, etc., to ensure that the multi-layer is inserted symmetrically. The magnetic circuit of the magnetic circuit structure is completely symmetrical. In this embodiment, the magnetic core is a symmetrical magnetic circuit structure, and a single air gap is located on the symmetry axis near the end of the magnetic core, and the magnetic core is disposed in the magnetic core socket. A fixed grounding pinhole is left in the center of the magnetic core insertion portion, and a pin is arranged in the fixed grounding pin hole, and the pin is connected to the grounding pin on the printed circuit board through the magnetic core grounding pin hole, and the air gap is provided with Element; in order to minimize the core volume, it must be The secondary winding area is the smallest, the axial core width of the uppermost and lowermost core of the magnetic core is smaller than the axial magnetic strip width of the intermediate layer, and the magnetic core jack on the skeleton is a chamfered magnetic core socket, the inner skeleton The chamfer size corresponds to the angle formed by the upper magnetic piece of the magnetic core shaft and the intermediate magnetic piece; the outer frame chamfer size matches the inner frame chamfer size; the inner frame is close to the end and is matched with the size of the Hall element. Symmetrical axis core The air gap is connected to the slot and the secondary coil end pin mounting slot is left; the upper end of the outer frame of the outer frame is provided with different size primary winding end fixing groove holes and the lower end is provided with an outer frame fixed pin mounting The slot, the protrusion on the cover of the outer casing is closely matched with the fixed groove on the outer frame, and the magnetic core slot on the outer frame has the anti-cree structure of the magnetic core grounding isolation plate to improve the insulation strength; The core coil assembly and sensor meet the requirements of automatic welding process such as secondary reflow soldering and wave soldering. The inner and outer bobbins, the outer shell and the cover plate for realizing the sensor's overall air-sealing are all injection molded with polyphenylene sulfide (PPS) high temperature resistant plastic.

It can be seen from the above that the axisymmetric magnetic circuit structure of the invention and a single air gap on the axis of symmetry cancel the influence of magnetic core remanence and electromagnetic interference, and the accuracy and anti-interference ability of the current sensor are greatly improved, and the small current measurement is performed. The accuracy is less than 0.2 FS.

The multi-layered magnetic core and the chamfered skeleton are matched with different punch widths, so that the coil path is short, the internal resistance is small, and the linear measurement range of the sensor is large under the same wire diameter and the same number of turns in the secondary winding region. The best electromagnetic isolation and coupling is formed by inserting the anti-lock structure with the inner and outer skeletons of the secondary winding and the primary winding respectively; the electronic circuit related to another patent application of the applicant is used together, so that the measuring range of the sensor reaches 3 times of the rated current, The response time is less than 1. OuS, -3db bandwidth is above 0-100KHZ.

The primary coil end of the outer frame is fixed and the groove is tightly fitted with the outer cover plate and the anti-cree structure with the magnetic core grounding plate is used to improve the insulation strength, and the insulation voltage reaches 5KV or more.

The structure is simple and easy to manufacture. The skeleton is mass-produced by injection molds. The primary and secondary coil prefabrication processing groups are assembled into a whole body with the inner and outer skeletons, the anti-locking and the skeleton structure with the primary and secondary winding ends, and the primary and secondary coil ends are installed firmly and conveniently.

The Hall element is installed in the air gap slot to ensure that the sensitive center of the Hall element is always located at the geometric center of the core air gap, and the installation consistency is good, thus ensuring the performance consistency of the sensor.

It is easy to connect with the circuit board and small in size. The primary and secondary coils can be pre-customized according to the rated current; the primary winding ends are immersed in tin and pass through the primary fixing holes on the skeleton; the ends of the secondary winding are respectively hooked around the secondary end fixing slots of the press-in frame On the lead pin, after the immersion tin, the inner and outer skeletons are inserted and locked, and the magnetic core is installed, so that the magnetic core wire assembly of the integral structure can be mounted on the sensor circuit board as a lead electronic component. , automatic integration with SMD PT/CN2012/000155 is mass-produced and miniaturized with current sensors.

The technical solutions provided by the embodiments of the present invention are described in detail above. The principles and implementation manners of the embodiments of the present invention are described in the following. The description of the foregoing embodiments is only applicable to help understand the embodiments of the present invention. The present invention is not limited by the scope of the present invention, and the description of the present invention is not limited to the details of the present invention.

Claims

1. An axisymmetric magnetic circuit core coil assembly for a full-PCB mounted high-precision closed-loop Hall current sensor, comprising: two skeletons and a magnetic core and a coil winding, wherein the skeleton is an inner skeleton and an outer skeleton, respectively. The inner bobbin is wound with a secondary coil winding, the outer bobbin is wound with a primary coil winding, the inner bobbin is interlocked with the outer bobbin, and the core is provided with a magnetic core slot and a jack; The magnetic core comprises a pair of different punch width multi-layer riveting magnetic pieces, the magnetic core is an axisymmetric magnetic circuit structure, and a single air gap is located on the axis of symmetry near the end of the magnetic core; the magnetic core is installed at a magnetic core slot and a socket in the skeleton; a Hall element is disposed in the air gap;

The core coil assembly is mounted on a sensor printed circuit board.

2. The axisymmetric magnetic circuit core coil assembly for a full PCB mounted high precision closed-loop Hall current sensor according to claim 1, wherein a fixed grounding pinhole is left at a center of the magnetic core insertion portion. A pin is disposed in the fixed ground pinhole, and the pin is connected to the ground wire of the printed circuit board through the core ground pin hole.

3. The axisymmetric magnetic circuit core coil assembly for a full PCB mounted high precision closed-loop Hall current sensor according to claim 1, wherein the number of layers of the multi-layer interposing structure magnetic core is singular ( 7 , 9, 1 1 .. . ) „

5. The axisymmetric magnetic circuit core coil assembly for a full PCB mounted high precision closed-loop Hall current sensor according to claim 1, wherein the uppermost and lowermost core magnetic sheets of the magnetic core are The width is smaller than the width of the core of the intermediate layer.

6. The axisymmetric magnetic circuit core coil assembly for a full PCB mounted high precision closed-loop Hall current sensor according to claim 5, wherein the core insertion hole on the inner bobbin is chamfered magnetic a core insertion hole, the inner frame chamfer size corresponds to an angle formed by the upper magnetic piece of the magnetic core axis magnetic piece and the intermediate magnetic piece; the outer frame chamfer size and the inner skeleton chamfer size

7. The axisymmetric magnetic circuit core assembly for a full PCB mounted high precision closed-loop Hall current sensor according to claim 1, wherein the inner bobbin is open near the end and has a size of the Hall element. A slot that mates with the air gap of the symmetrical shaft core and a slot for mounting the secondary coil end pin. 8. The axisymmetric magnetic circuit core coil assembly for a full PCB mounted high precision closed-loop Hall current sensor according to claim 1, wherein an upper end of the end baffle of the outer bobbin is provided with different sizes of primary windings. The end fixing groove hole and the lower end are provided with an outer frame fixing pin mounting slot, and the protrusion on the outer cover plate is closely matched with the fixing groove hole on the outer frame. The magnetic core slot on the outer bobbin has a magnetic core grounding wire isolation plate.

9. The axisymmetric magnetic circuit core wire assembly for a full PCB mounted high precision closed-loop Hall current sensor according to claim 8, wherein the inner and outer frames, the outer casing and the cover plate are both made of poly stud Ether (PPS) is injection molded from high temperature resistant plastic.