DESC:FIELD OF THE INVENTION
[0001] The present invention generally relates to electromagnetic interference (EMI) shielding. More specifically, it relates to EMI shielding for hall current sensors used in electronic devices for current measurements.

BACKGROUND
[0002] Electromagnetic compatibility (EMC) and electromagnetic interference (EMI) refer to the ability of electronic devices and systems to operate without being affected by, or causing interference to, other devices or systems. EMI can be caused by a variety of sources, including other electronic devices, power lines, and electrical storms. EMI can cause a range of problems, such as causing a device to malfunction or lose data, or causing the device to emit noise that can interfere with other devices. To reduce the effects of EMI, electronic devices and systems can be designed with shielding or filtering to block or reduce the amount of interference they receive.
[0003] There are several methods and materials that are typically used for electromagnetic interference (EMI) shielding/ Radio-frequency (RF) shielding. Few of them are metallic shielding, absorbing materials, conductive gaskets and filtering.
[0004] It is well known for a person skilled in the art that metallic shielding is most commonly used for reducing the effects of EMI. Metallic material like aluminium is generally preferred for electromagnetic interference (EMI) shielding since it is a good conductor of electricity and can effectively block or reflect electromagnetic fields.
[0005] Aluminium can be used in several forms for EMI shielding, including aluminium foil, mesh, aluminium foil shielded cables and perforated sheet. It can be used as a standalone shielding material or combined with other materials to improve its effectiveness. For example, it can be coated with a conductive polymer or used in conjunction with a layer of conductive foam to enhance its shielding properties.
[0006] The present invention intends to propose similar effective shielding mechanism for reducing the effects of EMI. It discloses an EMI/RF shielding for protecting hall current sensor using cap shielding mechanism made up of suitable materials for enhancing signal performance in electronic devices.

OBJECTIVES OF THE INVENTION
[0007] The primary objective of the present invention is to provide an arrangement for an electromagnetic interference (EMI) shielding/ Radio-frequency (RF) shielding mechanism having a simplified structure using a metallic cap for effective signal performance in electronic devices.
[0008] Another objective of the present invention is to provide the provide an arrangement for anshielding mechanism to hall effect current sensors to minimize power loss of the target current circuit with high reliability.

SUMMARY
[0009] The following summary is provided to facilitate a clear understanding of the new features in the disclosed embodiment, and it is not intended to be a full, detailed description. A detailed description of all the aspects of the disclosed invention can be understood by reviewing the full specification, the drawing, and the claims and the abstract, as a whole.
[0010] In order to achieve the aforementioned objectives, the present invention discloses an effective shielding mechanism designed to safeguard hall current effect sensors from EMI/EMC in electronic devices.
[0011] According to present invention, the arrangement for a shielding mechanism in an electronic device comprises, a laminated metal core made of iron stacked surrounding the phase terminal. A hall effect current sensor is incorporated which detects the magnetic field when current flows through the phase terminal sensor providing a hall voltage corresponding to the current flow to the phase terminal. The arrangement comprises a core holder aligned parallel to the hall current sensor for supporting the laminated metal core, made of iron. A metallic cap shield is equipped with Electro-deposit (ED) coating to protect from external electromagnetic interference (EMI) /Radio Frequency (RF) signal / Electromagnetic compatibility (EMC). An insulation sheet is positioned between the phase terminal and metallic shield cap while a rubber washer is placed above the shield, serving as a damping material to protect against vibrations.
[0012] In accordance with an embodiment of the present invention, the core holder is preferably made up of plastic material, but not limited to the same. The holder provides the isolation between PCB and metal core.
[0013] In accordance with yet another embodiment, the metallic cap shield is preferably made of aluminium, but any suitable material can be added.
[0014] Also, the phase terminal is preferably made of copper, but not limited to the same. The phase voltage output terminal is connected to a motor input of the electronic device.
[0015] Furthermore, a hall effect current sensor provides non-contact detection of direct and alternating currents, using a hall element. This minimizes power loss of the target current circuit and has a simple structure with high reliability. The hall element in the hall sensor, that is fitted inside a gap in the core, detects the magnetic field generated by the target current (I) and converts it into a voltage. The resulting sensor output voltage is conveyed back to a microcontroller of the electronic device.
[0016] Thus, the present invention provides EMI/RF shielding mechanism with simplified structure using a metallic cap for effective signal performance in electronic devices, such as a microcontroller.

BRIEF DESCRIPTION OF THE DRAWINGS:
[0017] The present invention will be better understood fully from the detailed description that is given herein below with reference to the accompanying drawings of the preferred embodiments of the present invention, which, however, should not be deemed to be a limitation to the invention to the specific embodiments, but, are for the purpose of explanation and understanding only.
[0018] FIG. 1 illustrates an arrangement of a shielding mechanism in an electronic device according to a preferred embodiment of the present invention.
[0019] FIG. 2 illustrates an exploded view of the arrangement of the shielding mechanism for an electronic device according to a preferred embodiment of the present invention.

REFERENCE NUMERALS:

100 – Arrangement for shielding mechanism for hall current effect sensor
102 – Laminated metal Core
104 – Hall effect Current Sensor
106 – Core Holder
108 – Metallic cap shield
110 – Insulation Sheet
112 – Rubber washer
114 – Phase terminal

DETAILED DESCRIPTION OF THE INVENTION
[0020] The following is a detailed description of the present disclosure depicted in the accompanying drawings. However, it may be understood by a person having ordinary skill in the art that the present subject matter may be practiced without these specific details. In other instances, well known methods, procedures, and/or components regarding the said method have not been described in detail so as not to obscure the subject matter of the disclosure. The subject matter of the disclosure will be more clearly understood from the following description of the embodiments thereof, given by way of example only with reference to the accompanying drawings, which are not drawn to scale.
[0021] If the specification states that a component or a feature “may” or “can” be included, that particular component or feature is not required to be included or have the characteristic. The use of open-ended terms like “comprising” and variations herein is meant to encompass the steps listed thereafter and equivalents thereof as well as additional items. As used herein, the singular forms “a,” “an,” and “the” designate both the singular and the plural, unless expressly stated to designate the singular only.
[0022] The use of the term “EMI” herein refers to electromagnetic interference. The use of the term “RF” signal herein refers to Radio Frequency signal. The use of the term “EMC” herein refers to electromagnetic compatibility. The term ED coating refers to Electro-deposit coating. The term “electromagnetic interference (EMI) shielding/ Radio-frequency (RF) shielding mechanism” may be referred to as “EMI/RF shielding mechanism” or “shielding mechanism” in the detailed description for ease of communication and the same may not be taken to denote any different entity.
[0023] The present invention discloses an arrangement for an shielding mechanism (100) to protect a hall current effect sensor to protect from EMI/EMC in electronic devices.
[0024] Referring to FIG. 1, an arrangement for a EMI/EMC/RF signal shielding mechanism (100) for an electronic device is shown. This arrangement (100) for an electronic device comprises, a laminated metal core (102) made of iron stacked around the phase terminal. along with a hall effect current sensor (104). The hall effect current sensor (104) detects the magnetic field generated when current flows through the sensor (104), providing a hall voltage based on the current flow to the phase terminal. A core holder (106) is employed to hold the laminated metal core (102) made or iron and is placed in parallel /aligned with hall current sensor (104). A metallic cap shield (108) that is provided with electro-deposit (ED) coating, preferably a cathodic electrodeposition (CED) coating (but not limited to it) is employed to protect from external electromagnetic interference (EMI) /RF signal / EMC as the CED coating has high corrosion protection and can stand up to 600 hours of salt spray testing wherein formation of white rusts is prevented. An insulation sheet (110) is placed between the phase terminal and the metallic cap shield (108); along with a rubber washer (112) placed atop the shield (108) to act as damping material to protect against vibrations. FIG. 2 illustrates an exploded view from core to washer (112) of the EMI shielding mechanism.
[0025] In accordance with one embodiment of the present invention, the core holder (106) is preferably made up of plastic material, but not limited to the same. The core holder (106) provides an isolation between PCB and metal core.
[0026] In accordance with another embodiment, the metallic cap shield (108) is preferably made of aluminium, but any suitable material can be added. Further, shield cables are same as aluminium foil sheets.
[0027] Also, the phase terminal is preferably made of copper, but not limited to the same. The phase voltage output terminal is connected to a motor input of the electronic device.
[0028] Furthermore, a hall effect current sensor (104) provides non-contact detection of direct and alternating currents, using a hall element. This minimizes power loss of the target current circuit and has a simple structure with high reliability. The hall element in the hall sensor (104), that is fitted inside a gap in the laminated metal core, detects the magnetic field generated by the target current (I) and converts it into a voltage wherein the sensor (104) output voltage is fed back to a microcontroller of the electronic device.
[0029] The present invention primarily addresses the EMI/EMC disturbances while performing radiated immunity test for electronic devices such as a microcontroller and proposes an effective shielding mechanism to overcome the same. Radiated immunity testing is a type of electromagnetic compatibility (EMC) test that is used to evaluate the susceptibility of electronic devices, such as microcontrollers, to electromagnetic interference (EMI) that is radiated through the air. The goal of this test is to determine whether a device can operate correctly in the presence of electromagnetic fields that are generated by other electronic devices or by external sources such as radio or television transmitters, power lines, and lightning.
[0030] Hence, the present invention provides the effective arrangement for the shielding mechanism by providing metallic shielding cap which is placed above hall current sensor in the laminated metal core assembly of the motor of the electronic device/microcontroller in order to prevent from external EMI/EMC disturbances.
,CLAIMS:WE CLAIM
1. An assembly of a shielding mechanism (100) for a hall effect current sensor in an electronic device, comprising:
a. a laminated metal core (102) with the hall effect current sensor (104) disposed in a gap in the laminated metal core (102), stacked around a phase terminal (114),
b. a core holder (106) to hold the laminated metal core (102) and placed parallelly or in alignment with the hall effect current sensor (104);
c. a metallic cap shield (108) coated with electro-deposit (ED) as a shield for the laminated metal core (102) to protect from external electromagnetic interference (EMI) or radio frequency (RF) signal or electromagnetic compatibility (EMC);
d. an insulation sheet (110) placed between the phase terminal and the metallic cap shield (108); and
e. a rubber washer (112) placed above the metallic cap shield (108) as a damping material to protect against vibration.

2. The shielding mechanism (100) as claimed in claim 1, wherein the core holder (106) provides an isolation between a printed circuit board (PCB) and the laminated metal core.

3. The shielding mechanism (100) as claimed in claim 1, wherein the core holder (106) is made of plastic.

4. The shielding mechanism (100) as claimed in claim 1, wherein the phase terminal is connected to a motor input of the electronic device.

5. The shielding mechanism (100) as claimed in claim 1, wherein the metallic cap shield (108) is made of aluminium.

6. The shielding mechanism (100) as claimed in claim 1, wherein the electro-deposit coating is a cathodic electrodeposition (CED) coating.