FR3139899A3 - Modular device for capturing variations in an electromagnetic field - Google Patents

Abstract

MODULAR DEVICE FOR CAPTURING VARIATIONS OF AN ELECTROMAGNETIC FIELD Device (100, 200) for capturing variations, natural or forced, of an electromagnetic field (E, B), comprising a support (10, 20), said support comprising at least one coil (12, 22), the coil comprising a metal wire (125, 225), wound around a hollow cylinder (122, 222), the coil (12, 22) comprising a removable permanent magnet (14 , 24) inserting into said hollow cylinder (122, 222), said magnet can also be removed in order to capture variations in the surrounding electromagnetic field (E, B) without the contribution of a clean magnetic field B magnet of said magnet. Abstract figure: figure 1

Description

Modular device for capturing variations in an electromagnetic field

The present invention belongs to the field of electromagnetic wave sensors.

The present invention relates more particularly to a device for capturing variations in the electromagnetic field, variations which can be caused naturally or by human activity, whether intentional or involuntary, said device comprising a support comprising at least one metal wire spool, notably made of copper, in which a removable permanent magnet can be inserted or removed depending on the desired capture, and of which one of the purposes is to produce sounds.

The present invention finds direct application in the fields of audio-visual (cinema, video games, etc.), the creation of experimental musical works or sound installations.

State of the art

The production of sound elements is a crucial and well-known step in the field of cinema for example, the first films of which appeared at the end of the ^19th century. In order to make the first projections more realistic, they were accompanied by sound effects. Since then, the methods of producing these sound elements, productions carried out by sound artists, have evolved, becoming more and more technical.

Other fields, such as the creation of experimental musical works, require discovering new methods of sound production in order to explore timbres and sounds previously unknown, thus creating new sounds.

In recent years, powerful software has made it possible to synthesize sounds in a very realistic manner using algorithms, physical models for example (musical instruments, complex sinusoidal signals, noises, etc.), digitally generating sound ambiances.

However, like a craftsman, the work of raw sound material is always sought after in the field of sound design to create original effects, based on reality and not synthesized.

The main objective of the present invention is to exploit variations, natural or artificial, of the electromagnetic field in order to produce new sounds, using as main components a copper coil in which a permanent magnet can be inserted or removed in order to generate sounds. original signals by means of heterogeneous ferromagnetic objects or everyday objects emitting electromagnetic waves (remote control, household appliances, etc.).

The electric guitar is a well-known musical instrument, one of whose principles is based on the capacity of one of its components, a pickup , generally composed of a copper coil and permanent magnets, said sensor converting variations of a magnetic field created by the vibrations of metal strings located near said sensor, into an electric current in the coil. This current is then amplified and returned in the form of acoustic waves using an electroacoustic device.

By way of example, document US4524667A presents an electromagnetic sensor suitable for use with a multi-stringed musical instrument having strings formed of a ferromagnetic material. The sensor is formed of a first coil of wire wound in a first direction, on which a second coil of wire wound in a second direction is positioned, the coils having an elongated oval shape, a permanent magnet assembly is positioned in the central cavity of the coils. Variations in the magnetic field near the sensor, generated by the vibrations of at least one string, produce an electrical signal in the coils.

This sensor is an integral part of the instrument on which it is installed. In addition, the spectral content of the electrical signal produced remains limited because said content is a function of the size, the length as well as the tension of the strings, defining a vibration frequency of said strings. Finally, the permanent magnet assembly is fixed in the sensor, and cannot be removed to use said sensor without it.

Other fields, such as measurement, exploit the association of permanent magnets with coils in order to generate an electrical signal which is the result of a conversion, by a sensor, of a physical phenomenon.

Thus, document EP2210130A2 describes a speed sensor comprising a static part and a dynamic part arranged concentrically inside the static part. Each part has two permanent magnets. The static part further comprises a measuring coil to measure in particular the displacement of the dynamic part. First of all, the electrical signal generated by the sensor results from the movement of the dynamic part. In other words, if no movement is generated, no electrical signal is produced. Next, and again, this sensor is not designed to be used without a magnet.

Presentation of the invention

The present invention proposes an innovative solution making it possible to capture natural variations in the electromagnetic field, caused by human activity voluntarily or involuntarily, or induced by a multitude of components, in particular for sound composition, with an easy-to-use, compatible device. with general public acquisition systems.

This device makes it possible to explore new methods of sound production and to generate new libraries of noises that can be used in different fields such as cinema, electronic music or the creation of experimental sound works linking arts, sciences and technologies.

For this purpose, the present invention relates to a device for capturing variations, natural or forced, of an electromagnetic field, comprising a support, said support comprising at least one coil, the coil comprising a metal wire, wound around a hollow cylinder. This device is remarkable in that the coil comprises a removable permanent magnet inserting into the hollow cylinder of said coil, said magnet can also be removed in order to capture variations in the surrounding electromagnetic field without the contribution of a specific magnetic field of said magnet. This modular capacity advantageously offers the possibility to a user, by means of several configurations, of capturing variations in an electromagnetic field, and this with the same device.

According to a particular characteristic, the support comprises at least one opening revealing the removable permanent magnet and/or the coil.

According to another particular characteristic, the permanent magnet is positioned in the device, via a passage located at the rear of the support, without requiring dismantling of said support, facilitating the insertion and removal of said magnet.

Advantageously, the device further comprises at least one module generating a disturbance of the electromagnetic field generating the production of an electric current in the coil, in particular for the creation of sound effects.

Advantageously, the rear shell of the support is screwed to the front shell of said support by means of screws or perhaps clipped to the front shell in order to facilitate the assembly of the support.

According to another particular characteristic, the coil is fixed on a printed circuit board placed in the support by means of a glue or an adhesive, facilitating the mounting of said coil on said card. The coil can also be held on the printed circuit board by means of screws, allowing in particular easy replacement of said coil.

Advantageously, the device comprises at least two identical coils, all or part of which contain a permanent magnet in order to obtain a heterogeneous association to capture variations in the electromagnetic field.

Advantageously, the device comprises at least two different coils, allowing capture with a complex response for the same variations in the electromagnetic field.

The fundamental concepts of the invention having just been explained above in their most basic form, other details and characteristics will emerge more clearly on reading the description which follows and with reference to the appended drawings.

Presentation of the drawings

The figures are given for purely illustrative purposes for a better understanding of the invention without limiting its scope. The different elements can be represented schematically and are not necessarily on the same scale. In all the figures, identical or equivalent elements bear the same numerical reference.

It is thus illustrated in:

: an exploded perspective view of a modular device for capturing variations in an electromagnetic field according to a first embodiment of the invention;

: a perspective view of the modular device according to a first embodiment of the invention;

: a section view following the section plane AA of the ;

: a perspective view of modules to be positioned on the modular device;

: a perspective view of modules installed on the modular device according to a first embodiment;

: an exploded perspective view of a modular device for capturing variations in an electromagnetic field according to a second embodiment of the invention;

: a perspective view of a module installed on the modular device according to a second embodiment;

: another perspective view of a module installed on the modular device according to a second embodiment.

Detailed description of embodiments

It should be noted that certain technical elements well known to those skilled in the art are described here to avoid any insufficiency or ambiguity in the understanding of the present invention.

In the embodiments described below, reference is made to modular devices for capturing variations, natural or caused by human activity intentionally or unintentionally, of an electromagnetic field which can in particular be used for sound composition, without that this is not limiting.

There represents an exploded perspective view of a modular device 100 for capturing variations of an electromagnetic field ( E , B ) according to a first embodiment, mainly comprising a support 10, a printed circuit board 11, a coil 12 and a permanent magnet 14.

In this embodiment, the support 10 is divided into two parts, a handle 10a and a capture zone 10b, and comprises a front shell 101 and a rear shell 102.

The front 101 and rear 102 shells are assembled by means of screws 109 for fixing the shell, inserting at the level of the rear shell 102 via through holes 107, and passing through the printed circuit board 11 at the level of passages 112 for assembling the support, said screws being housed in the front shell 101 in tapped holes (not shown here). The assembly of the front shell 101 and the rear shell 102 can also be carried out by other methods known to those skilled in the art, such as clipping or gluing.

In order to stiffen the rear shell 102 while minimizing the quantity of material used to manufacture said shells, the latter comprises at least one longitudinal rib 104 as well as at least one lateral rib 105. This design can also be applied to the hull before 101.

The front shell 101 and the rear shell 102 of the support 10 are preferably manufactured by plastic injection or by additive manufacturing.

Inside, the support 10 includes the printed circuit board 11 on which a multitude of electronic components 117 are soldered (preamplifier, filter, diode, resistor, capacitor, etc.), a socket 116 (jack, XLR, USB, etc.) making it possible to connect a cable (not shown here) to transmit the captured signal, said socket being located on the front of said support through socket openings 106a and 106b present respectively on the front shell 101 and the rear shell 102, said card also comprising at least one coil 12.

In the embodiment shown in , the modular device 100 comprises four coils 12, without this being limiting.

Each coil 12 has a front face 121 as well as a rear face 123, connected by a hollow central cylinder 122, said cylinder being surrounded by a metal wire 125, preferably made of enameled copper with a diameter equal to 0.1 mm, without this is not limiting. The rear face 123 of the coil 12 has two vertical slots 124 into which the ends of the metal wire 125 are inserted so that they can be soldered to the printed circuit board 11.

In this example, the height and diameter of the coil 12 are 15 mm and 20 mm respectively. The coil contains a number N of turns ranging from 1500 to 4000. These dimensional characteristics are not limiting. Furthermore, the modular device 100 can contain on its support 10 coils 12 having different dimensions in order to obtain different configurations on the same device.

The coil 12 is held on the printed circuit board 11 by means of fixing screws 118 passing through holes 111 for fixing the coil, said screws being housed in tapped holes (not shown here) present in the rear face 123 of said coil. Maintaining the coil 12 on the printed circuit board 11 can be achieved by other means known to those skilled in the art, such as the use of suitable glues or adhesives.

Advantageously, each coil 12 accommodates in its center a removable permanent magnet 14, preferably neodymium and of cylindrical shape without this being a limitation, and of magnetic field B own _magnet . The removable permanent magnet 14 comprises a magnetized body 142 and a silicone heel 143, glued to said body.

In order to be able to easily insert and remove the removable permanent magnet 14, the rear shell 102 as well as the printed circuit board 11 respectively have magnet through holes 108 and 115.

The insertion of the removable permanent magnet 14 is in this example carried out from the rear of the support 10, by pushing said magnet into the magnet passage 108 of the rear shell 102, then into the magnet passage 115 of the printed circuit board 11, up to the hollow central cylinder 122 of the coil 12. The mechanical play between these elements is minimal so that the adjustment is sliding between the removable permanent magnet 14 and the hollow central cylinder 122 in particular.

In other embodiments, the removable permanent magnet 14 can be inserted from the front of the support 10.

The removable permanent magnet 14 is correctly positioned when the heel 143 of said magnet abuts the rear shell 102. Furthermore, when the removable permanent magnet 14 is inserted into the coil 12, said magnet has a front face 141 which is is in the same plane as the front face 121 of said coil, without this being a limitation: in fact, the front face 141 of the magnet 14 can also protrude from the plane where the front face 121 of the coil 12 is located , or being set back, according to other embodiments.

In the embodiment shown in , the magnet 14 is held in the support 10 by means of the pressure which is exerted on the internal wall of the passage hole 108, when the heel 141 is inserted there. Those skilled in the art can also design other means of holding the magnet 14 in the support 10, in particular by clipping, screwing, or by magnetism by adding a ferromagnetic part at the level of the through hole 108.

Finally, the modular device 100 comprises a multitude of ferromagnetic modules 13, as shown in particular in as well as the . The use of the modules 13 with the support 10 makes it possible to locally create variations in the electromagnetic field at the level of the coils 12. The other modular aspect of the modular device 100 is that it can comprise in whole or only in part, removable permanent magnets 14 in the coils 12, and still be functional. In the case where no removable permanent magnet is inserted in the coils 12, the preferred use is that which consists of using the modular device 100 as a sensor of natural variations or induced by human activity, of an electromagnetic field ( E , B ) surrounding.

The combination on the same modular device 100 of coils 12 in which removable permanent magnets 14 are, or not, inserted, is also a case of use of said device.

There represents a perspective view of the modular device 100 when it is assembled, without the module 13.

In this embodiment, the four removable permanent magnets 14, and the four coils 12 form the capture zone 10b of the modular device 100, arranged in openings 103 present in the front shell 101.

Once assembled, the contour of the coil 12 fits perfectly inside the opening 103 with minimum mechanical play.

Advantageously, the front faces 121 of the coils 12 and the front faces 141 of the removable permanent magnets 14 are in the same plane, facilitating the positioning of modules 13, as shown in Fig. .

In other embodiments, the front shell 101 does not have openings 103, therefore not revealing the coil 12 as well as the removable permanent magnet 14.

In other embodiments, the opening 103 only reveals the removable permanent magnet 14.

There represents a sectional view along the section plane AA of the modular device 100 shown in .

The arrangement of the different elements which make up the capture zone 10b of the modular device 100 is clearly visible.

First of all, the positioning of the coil 12 in the opening 103 is highlighted by this sectional view, where the metal wire 125, wound around the hollow central cylinder 122, the front face 121 and the rear face 123 of the coil 12 held on the printed circuit board 11, are perfectly integrated there.

Then, the insertion of the removable permanent magnet 14 within the coil 12 is also visible, as well as its vertical support by means of the silicone heel 143 which abuts at the level of the magnet passage 108 of the rear shell 102.

Again, it is possible to note the coplanarity of the front faces 121b and 141 respectively of the coil 12 and the removable permanent magnet 14.

There represents a perspective view of modules 13 to be positioned on the modular device 100.

On the , five examples of modules 13 are represented. These examples are not limiting, the person skilled in the art can easily conceive of others.

There represents a first module 13a, mainly of spherical shape, consisting of a ferromagnetic wire 131a and a hooking magnet 132b. The winding of the ferromagnetic wire 131a recalls the winding of wire constituting the springs. At the top of the module 13a is a gripping loop 133a which allows said module to be manipulated by extending and compressing it.

When the module 13a is fixed by means of the attachment magnet 132a on the front face 141 of the removable permanent magnet 14, the successive elongations and compressions generate variations in a magnetic field B near the capture zone 10b, generating an electric current I _13a (t) in the coil 12.

A second module 13b which comprises a ferromagnetic ring 131b, suspended from a wire 133b, connected to a bracket 134b, preferably made of plastic, on the

base of which a hooking magnet 132b is glued, is shown in the .

When the module 13b is fixed by means of the attachment magnet 132b on the front face 141 of the removable permanent magnet 14, the oscillations of the ferromagnetic ring 131b or the percussions carried out on said ring will also generate variations of a magnetic field B near the collection zone 10b, then generating an electric current I _13b (t) in the coil 12, different from the electric current I _13a (t) generated by the module 13a.

A third module 13c comprises a handle 131c, one face 135c of which comprises two magnets 132c of rectangular shape on which, a movable magnet 133c of cylindrical shape is magnetized and capable of sliding along the magnets 132c, as represented by the double arrow on there . At rest, the magnet 133c finds an equilibrium position located in the center of the two magnets 132c.

In these examples of modules 13, a fourth module 13d mainly comprises a ferromagnetic wire 131d, arranged in the form of a cylindrical spring, as well as two magnets 132d and 133d glued to the ends of said wire.

An electric current is for example generated in the coil 12 by friction or by percussion of the module 13d on the magnet 14.

Finally, a fifth module 13e mainly metallic, with a shape close to a cylinder and of which at least one face 131e has roughness or a metallic texture makes it possible to generate by friction or by percussion, a current in the coil 12, and thus produce different sound effects.

There represents a perspective view of the modules 13a and 13b installed simultaneously on the modular device 100. This non-limiting example makes it possible to visualize a practical case of use of the modular device 100. Advantageously, only one module 13a-d can be used, or the modules 13a-d can be interchanged as desired in order to generate different disturbances of the magnetic field B near the capture zone 10b.

In the example shown in , the total electric current I _tot (t) is equal to the sum defined in equation 1,

where n is the total number of coil assembly 12, with or without removable magnet 14, which make up the capture zone 10b, equal to 4 in this example, and where I _noise (t) is the electric current present in the modular device which is linked to electromagnetic noise, and which can be negligible in certain cases compared to the two previous terms.

There represents an exploded perspective view of a modular device 200 for capturing variations in the electromagnetic field ( E , B ) according to a second embodiment of the invention.

The modular device 200 mainly comprises a support 20, a coil 22, a removable permanent magnet 24, an electric cable 25 as well as a connector 26 (jack, xlr, usb, etc.).

The support 10 comprises a shell 201, a cable passage 206, allowing the cable 25 to be inserted into said support to connect it to the coil 22, an opening 203 into which said coil is inserted.

The coil 22 comprises a front face 221 as well as a rear face 223, connected by a hollow central cylinder 222, said cylinder being preferably surrounded by an enameled copper wire 225 with a diameter equal to 0.1 mm, without this or a limitation.

The two ends of the wire 225 are connected to the conductive wires 251 and 252 of the electrical cable 25, by means of different techniques known to those skilled in the art, such as by welding or by connectors.

The permanent magnet 24 has a front face 241, a magnetized body 242 as well as a silicone heel 243. When the permanent magnet 24 is inserted into the coil 22, its front face 241 is in the same plane as the front face 221 of said coil and the heel 243 of said magnet abuts at the rear of the shell 201. As for the device 100, the permanent magnet 24 can be held by different means known to those skilled in the art, such as by screwing, clipping.

There and the respectively represent perspective views of modules 23a and 23b installed on the modular device 200.

These examples are not limiting.

Advantageously, the modular device 200 presented in Figures 6 and 7A-B is compact, facilitating its transport and storage.

The modular device 200, due to its compactness, can in particular be used in a restricted work space or magnetized to a ferromagnetic object or surface.

Claims (10)

Device (100, 200) for capturing variations, natural or forced, of an electromagnetic field ( E , B ), comprising a support (10, 20), said support comprising at least one coil (12, 22), the coil comprising a metal wire (125, 225), wound around a hollow cylinder (122, 222), characterized in that the coil (12, 22) comprises a removable permanent magnet (14, 24) inserting into said hollow cylinder (122, 222), said magnet can also be removed in order to capture variations in a surrounding electromagnetic field ( E , B ) without the contribution of a clean magnetic field B _magnet of said magnet. Device (100, 200) according to claim 1, in which the support (10,20) comprises at least one opening (103, 203) revealing the removable permanent magnet (14, 24) and/or the coil (12, 22). Device (100, 200) according to claim 1 or 2, in which the permanent magnet (14, 24) is positioned in said device, via a passage (108, 208) located at the rear of the support (10, 20) , without requiring dismantling of said support, facilitating the insertion and removal of said magnet. Device (100, 200) according to any one of the preceding claims, said device further comprising at least one module (13a-e, 23a-b) generating a disturbance of the electromagnetic field ( E , B ) generating the production of a electric current I(t) in the coil (12, 22), in particular for the creation of sound effects. Device (100) according to any one of the preceding claims, in which the rear shell (102) of the support (10) is screwed to the front shell (101) of said support by means of screws (109). Device (100) according to any one of the preceding claims, in which the rear shell (102) of the support (10) is clipped to the front shell (101) of said support in order to facilitate assembly of the support. Device (100) according to claim 5 or 6, in which the coil (12) is fixed on a printed circuit board (11) placed in the support (10) by means of a glue or an adhesive, facilitating the mounting said coil on said card. Device (100) according to claim 5 or 6, in which the coil (12) is held on the printed circuit board (11) by means of screws (119), allowing in particular easy replacement of said coil. Device (100) according to claim 1, comprising at least two identical coils (12), and in which all or part contain a permanent magnet (14) in order to obtain a heterogeneous association to capture variations in the electromagnetic field ( E , B ). Device (100) according to claim 1, comprising at least two different coils (12), allowing capture with a complex response for the same variations in the electromagnetic field ( E , B ).