Field of the Invention

The present invention relates to a device for inductively coupling an appliance to an electrical system. It also relates to an inductive coupling which couples an appliance to a single electrical cable. The invention also relates to an inductive coupling which is separable for coupling to the cable wherein a separable part may be embedded in the appliance.

Background

Traditional electrical appliances are supplied with electricity by electrical contact with a power supply installation. An electrically conductive portion of the power supply installation must be available for the contact. Inadvertently touching the exposed cable can provide a serious electrical shock.

Inductive coupling appliances connected to a sheathed cable overcome the electrical hazard. Examples of devices to connect a twisted pair of sheathed cable to an appliance so that power may be inductively transferred from the twisted pair to the appliance are disclosed in the following publications: US-B-4904879 (Rudy), WO-A2-2016/012894 (Koninklijke Philips), US-A1-2002/0175795 (Black), and GB-A-2497428 (Isotera).

Examples of devices to connect a single cable to an appliance so that power may be inductively transferred from the single cable to the appliance are disclosed in the following publications: US- A 1-2007/0076459 (Limpkin), J P-A-200105774 (Autonetwork), EP-A1 -0587923 (Urd), and GB-A-2372380 (Microlights).

These prior art disclosures disclose how devices may be arranged to safely connect a sheathed cable to an appliance so that power may be safely drawn from cable by induction. They overlook an issue of inconvenience if the appliances require rearranging.

An object of the present invention is to physically secure a cable to an inductive coupling device as well inductively couple the cable to the device in one convenient simple operation. Summary

According to a first aspect of the invention there is provided an inductive coupling device for transferring power from a cable to an electrical appliance, comprising: first and second couplers having first and second ferrous cores respectively, wherein at least at least one coupler is physically and inductively joined to the appliance; the couplers are connectable to arrange the cores into a ferrous loop for retaining the cable wrapped around the one of the cores.

Preferably at least one coupler comprises a rotatable collar around a portion of its ferrous core; the couplers are connectable for retaining the cable wrapped around the collar.

Advantageously the inductive coupling device is movable along the cable as the cable wrapped around the collar rotates the collar.

Advantageously the appliance is movable to along the cable with minimum physical resistance. The cable around the collar urges the collar to rotate as the appliance is moved along the cable. A low friction mounting of the collar on the coupler permits the collar to rotate with low friction around the ferrous core.

Preferably the portion of the ferrous core collared by the rotatable collar is bounded by a face connecting the ferrous cores when the couplers are joined.

Advantageously the rotatable collar is easily put on the ferrous core and taken off the ferrous core by passing the collar past the face.

Preferably at least coupler comprise a portion of its ferrous core which is rotatable with respect to an adjoining portion of its ferrous core about an axis substantially parallel to the ferrous loop; the couplers are connectable for retaining the cable wrapped around the portion of the ferrous core with is rotatable. Advantageously the inductive coupling device is moveable along the cable as the cable wrapped around the rotatable portion, rotates the rotatable portion.

Preferably the inductive coupling device is arranged for transferring a user selected amount of induced current from the electrical cable which is coupled to the device, to the electrical appliance. Preferably collars of different diameter and different material are interchangeable around the ferrous core. Collars formed of highly electrically insulative material and a diameter substantially the same as the ferrous core provide for a high amount of induced current to be transferred from the cable around collar to the ferrous loop by electromagnetic induction. A user may place a collar of highly insulative material around the ferrous core to select a high amount of induced current to be transferred.

Collars formed of electrically conductive material provide for relatively less induced current to be transferred than another collar which is formed of insulative material. Advantageously by selecting a collar formed a material of a preselected conductivity the user may select the amount of induced current from the electrical cable which is transferred.

Preferably the inductive coupling device comprises a connecting means for connecting the first coupler with a second coupler.

Advantageously the connecting means arranges the couplers so that as the couplers are connected, the cores are arranged into the ferrous loop for retaining the cable wrapped around the collar.

Advantageously the ferrous loop provides a loop for magnetic flux to circulate. The flux is induced in the ferrous loop by time varying current in the cable around the collar.

Preferably a conductive loop comprised of electrically conductive material is provided in the device so that current in the cable induces current in the conductive loop thereby supplying electrical current to the electrical appliance. The conductive loop is formed around a portion of the ferrous core of one of the couplers.

Advantageously the cable is physically secured to the coupling device as it is inductively coupled to the coupling device by connecting the first and second coupler.

Preferably the connecting means includes a permanent magnet that connects the first and second couplers. The first and second couplers are thereby easily connected by bringing them close together.

Preferably a ferrous stud is provided on one of the couplers for connecting to the permanent magnet on the other coupler. Advantageously only one magnet is needed. The ferrous stud is ideally easily and inexpensively formed.

Preferably the stud is supported on a branch off the magnetic loop provided on either the first or second coupler.

Preferably a portion of the magnetic loop includes the permanent magnet. Advantageously a portion of the magnetic loop transfers in use a combined flux from the permanent magnet and flux induced in the magnetic loop by current in the cable.

According to another aspect of the invention there is provided an appliance comprising the inductive coupling device described herein.

Preferably the magnetic loop is arranged to magnetically saturate at a preselected level of flux which provides a maximum preselected level of power to the electrical appliance. Preferably the magnets are located so as not to cause saturation of the magnetic loop with flux solely from the magnets.

Advantageously upon connection of the couplers there is formed a closed magnetic circuit comprising a portion of the magnetic loop. By allowing the magnetic circuit, which holds the couplers together, to share a portion of the magnetic loop, which inductively couples the cable to the electrical appliance, the inductive coupling device is made cost efficient.

Preferably the connection means is arranged to connect the couplers to leave a gap therebetween. Preferably the connection means sets the distance of the gap upon connection of the couplers which transfers a predetermined amount of power from the cable by induction to a maximum power requirement that is available for normal operation of the appliance. Advantageously by altering the connection means, the coupling device is made suitable for operation of the appliance by a power supply which provides a constant current amplitude alternating current (AC) and provides a preselected time varying voltage and current to the appliance from the cable.

Preferably a portion of the magnetic loop comprises a ferrous core. Preferably the couplers comprise a non-conductive and non-magnetic material to support the ferrous core. Safety of the inductive coupling device is thereby enhanced as a user can connect and disconnect the couplers without touching any electrically conductive material.

Preferably the core comprises an interface surface at a junction in the magnetic loop between couplers, in which the interface surface forms a portion of the surface of the coupler. Advantageously, upon connection of the couplers the interface surfaces of each coupler are either brought into contact one with another or a preselected gap is defined between them by the connecting means.

Preferably the interface surface has a preselected area to restrict flux through the loop. The power which may be transferred from the cable to the appliance by induction is thereby limited to the amount of power required by the appliance in normal use.

Preferably the inductive coupling device is formed integrally with the appliance. Thus the appliance is conveniently coupled to the cable by simply wrapping a turn around a portion of either coupler which forms a portion of the magnetic loop when the couplers are connected.

Preferably the inductive coupling device comprises an electric converter to receive the current supplied by the conductive loop and transform it into a voltage and current matched to an electrical requirement of the appliance. Preferably the electric converter receives electrical power inductively transferred through the ferrous cores transform it into a voltage and current matched to an electrical requirement of the appliance. Advantageously, electrical power taken from the cable by induction is converted efficiently from an alternating voltage and current induced in the conductive loop to a voltage and current suitable for use by the appliance.

Preferably the appliance comprises a housing which holds one of the couplers, preferably the first coupler.

Preferably the appliance or the inductive coupling device comprises an electrical converter contained in the housing to convert power supplied through the ferrous cores to voltage and current for the apparatus.

Advantageously appliance is easily held without touching the electrical converter contained in the housing.

Preferably a first coupler is held within the housing. Preferably a second coupler is fastened by a flexible fastener to the first coupler or to the housing. The first interface surface of the core of the first housing is exposed upon disconnecting the first coupler from the second. The second coupler is left dangling from the flexible fastener. A second interface surface of a core in the second coupler is also exposed by disconnection. To couple the cable to the inductive coupling appliance all that is required is for a turn of the cable to be wrapped around a portion of either core and then for the couplers to be connected. The first coupler is held conveniently within the housing. Advantageously, a person has two hands available for wrapping the cable around a portion of the core in the first coupler. The second coupler is suspended by the flexible fastener. Advantageously, a user may position the second coupler with one hand without having to support the entire weight of the second coupler and wrap a turn around a portion of the core in the second coupler.

Preferably the second coupler comprises a non-conductive casing. The casing is ideally held by user handling the second coupler.

Preferably the ferrous core around which the collar is placed is formed with a channel or slot between a portion of the core surrounded by the collar and a neighboring portion of the ferrous core of the coupler which the core surrounds.

Preferably at least one of the ferrous cores comprises the channel or slot for the cable, wherein a portion of the ferrous core adjacent the channel or slot is bounded by a face for connecting the ferrous cores when the couplers are joined.

Advantageously the channel provides a space for the cable to move with the cable turns around the collar without interference from the neighboring portion of the ferrous core.

Preferably connecting the couplers retains the cable in the channel.

Preferably the channel in the inductive coupling device is formed in the second coupler. Preferably the channel is formed from a non-conductive material supporting a portion of the magnetic loop. A user may wrap the cable around a portion of the magnetic loop in the second coupler so that the cable is placed in the channel. Advantageously, when the user connects the couplers, there is room for the cable in the channel so that the two couplers may be brought together without interference of the cable. Preferably the non-conductive casing of the second coupler comprises a slot for the cable as a passage through the non-conductive casing to the channel. Preferably the slot provides for secured side-by-side passage of two ends of the electrical cable upon connection of the couplers. The slot is open ended. The open end of the slot is exposed when the couplers are disconnected so that the cable can be easily inserted through the open end of the slot and into the channel. A single turn of the cable around the magnetic loop brings both ends of the cable side by side. The two side- by-side ends conveniently pass through the slot. Advantageously, the two couplers may be brought together for connection. Conveniently the wrapped cable in the channel with passes through the slot does not interfere with connecting the couplers.

According to another aspect of the invention there is provided an electrical system comprising: an electrical appliance having an inductive coupling device described herein and comprising the cable. Preferably the electrical system comprises a power supply to provide a time varying electrical current to the cable coupled by a turn around the magnetic loop of the coupling device.

In a preferred embodiment, the electrical system only requires a single electrical cable to inductively transfer power from the power supply to the electrical appliance. Preferably the electrical system comprises a plurality of the electrical appliances, wherein each of the appliances is coupled to the cable by a turn around the magnetic loop. Several different appliances each with its own inductive coupling device are easily and conveniently connected to the cable.

Preferably each inductive coupling device of each appliance is arranged for a time average constant current provided as alternating current from the power supply to transfer up to an amount of power required for normal operation of the appliance. Advantageously, there is no need to adjust the voltage or current supplied by the power supply when an additional appliance is coupled to the cable.

Optionally a coupling device may be addressable, by way of a separate communication device, such as radio frequency (RF) device to vary an electrical and/or another characteristic of the coupling device. Alternatively, an electrical and/or another characteristic of the coupling device may be varied via a communication channel such as a fibre optic pathway.

Preferably the electrical system comprises a rail for carrying the appliance, wherein the cable is suspended between ends end of the rail. Preferably in the electrical system at least one coupler comprises rotatable collar around a portion of its ferrous core; the couplers are connectable for retaining the cable wrapped around the collar; and wherein collar is arranged to support the weight of the appliance as the collar rolls along the rail. Preferably the coupler comprising the collar is connectable to the coupler physically and inductively joined to the appliance.

Preferably in the electrical system, the ferrous core of the coupler comprising the collar comprises a support to end under and support the ferrous core of the coupler physically and inductively joined to the appliance to carry the weight of the appliance. Preferably the electrical system comprises a plurality of the electrical appliances, wherein each of the appliances is coupled to the cable by at least one turn around the magnetic loop.

The invention will now be described, by way of examples only, with reference to the drawings in which: Brief Description of the Figures

Figure 1 shows a view from a top side of an electric appliance comprising an inductive coupling and electric converter;

Figure 2 shows a view from a rear side of the electric appliance of Figure 1 ;

Figure 3 shows a view from the rear side of the electric appliance as in Figure 2 in which the inductive coupling is opened to receive an electrical cable;

Figure 4 shows a view from the front side of six of the electric appliances side by side and an electrical power supply from which two electrical cables extend in parallel alongside the two electrical appliances;

Figure 5 shows a view from the rear side of three of the electrical appliances, and one of the electrical cables strung from the power supply to the three appliances, where the inductive couplings are closed around the electrical cable to provide electrical power from the cable to the appliances;

Figure 6 shows a view from the rear side of two of the electrical appliances side by side and the one the electrical cables strung from the power supply to the five appliances; Figure 7 shows a view from the rear side of five of a second type of electrical appliance, where each of the second type of electrical appliances comprises one of the inductive couplings through which one of the electrical cables is strung from the power supply; Figure 8 shows a view from the rear side of four of a third type of electrical appliance, where each of the third type of electrical appliances comprises one of the inductive couplings through which one of the electrical cables is strung from the power supply;

Figure 9 shows a view from the rear side of the first, second, and third type of electrical appliance connected in sequence by an electrical cable extending from a power supply and through the inductive coupling of each of the three different appliances;

Figure 10 shows a schematic view of six of the electrical appliances, an electrical cable strung from the power supply to the six appliances, where the appliances comprise an inductive coupling closed around the electrical cable to provide electrical power from the cable to the appliances;

Figure 11 shows a schematic view of an electric appliance comprising a first coupler of an inductive coupling to provide electricity to a load through a rectifier having output terminals connected in parallel to a capacitor and a constant current buck inverter; Figure 12 shows a schematic view of an electric appliance comprising a first coupler of an inductive coupling to provide electricity directly to a load;

Figure 13 shows a schematic view of an electric appliance comprising a first coupler of an inductive coupling connected to a rectifier to provide DC current to a load;

Figure 14 shows a schematic view of an electric appliance comprising a first coupler of an inductive coupling connected to a rectifier having output terminals connected to capacitor and load arranged in parallel to provide DC current to a load;

Figure 15 shows a schematic view of an electric appliance comprising a first coupler of an inductive coupling to provide electricity to a load through a rectifier having output terminals connected in parallel to a capacitor and a step down/up buck inverter; Figure 16 shows a schematic view an example of electric appliances comprising a first coupler of an inductive coupling connected load drive circuits operable by wireless control;

Figure 17 shows a schematic view an example of electric appliances comprising a first coupler of an inductive coupling connected load drive circuits comprising a buck voltage or current inverter in communication with a wireless controller;

Figure 18 shows a plan view of a second coupler of an inductive coupling wherein the second coupler comprises a rotatable collar around a ferrous pole of the coupler;

Figure 19 shows a sectional view of the second coupler of an inductive coupling in shown in Figure 18, wherein the second coupler comprises a rotatable collar around a ferrous pole of the coupler;

Figure 20 shows an example of a ferrous core comprising a cylindrical central pole separated by a circular groove from poles on the flanks of the unit;

Figure 21 shows an example of a ferrous core comprising a rectangular central pole separated by a groove from poles on the flanks of the unit;

Figure 22 shows a schematic view of an electric appliance comprising an inductive coupling and electric converter comprising a bridge rectifier;

Figure 23 shows a schematic view of an electric appliance comprising an inductive coupling with a heat sink; Figure 24 shows a schematic view of a rail system for positioning appliances comprising inductive couplings;

Figure 25 shows a detailed view of an electrical system in profile including an appliance comprising an inductive coupling device supported on a rail; and

Figure 26 shows a front view of an electrical system looking axially at a rotatable collar carrying the weight of an appliance on a rail.

Detailed description:

An electrical appliance 1000 is shown in Figure 1. The appliance 1000 comprises an electrical illumination device 100, an electric converter which is contained in a housing 200, and an inductive coupling 300. The electrical illumination device comprises a window lens, reflector, and light bulb. The bulb is held in position by a socket so that light from the bulb is reflected though the lens to provide useful illumination.

The socket comprises electrical contacts for the bulb. The contacts are electrically connected to the electrical converter.

The electrical converter provides electricity at a suitable voltage and current level for the bulb. The converter also provides the electricity as either direct or alternating current as suitable for the bulb. The converter is arranged to provide alternating current of a preselected waveform and frequency to operate the bulb efficiently. The electrical converter is electrically connected to the inductive coupling 300. Figure 2 shows the inductive coupling 300 attached to the converter housing 200.

The inductive coupling device 300 transfers power from the cable 3001 shown in Figure 5 to the electrical appliance 100. The inductive coupling device 300 comprises first and second couplers 310, 320 shown in Figure 3. Figure 2 shows a rear view of the electrical appliance 1000. The inductive coupling 300 is located on the rear side of the electrical appliance 1000. The electrical illumination device is located at the front of the electrical appliance.

In use the rear side of the electrical appliance 1000 is fitted on a bracket for attachment to a wall or ceiling or to set in a recess in a wall or ceiling. When the appliance is set in the recess, the front of the appliance is visible. The rear side of the appliance which is set in the recess is not visible. The inductive coupling is obscured behind the electrical converter housing 200, so that to a user of the appliance the inductive coupling is not visible.

Another rear view of the appliance 1000 is shown in Figure 3. The inductive coupling 300 is shown uncoupled in Figure 3. The inductive coupling 300 is divided into a first coupler 310 and a second coupler 320.

The first coupler 310 is partly contained in the converter housing 200. The second coupler 320 is connected by a chain 400 to the first coupler 310. The length of the chain is about the same length as the first and second coupler. When the first and second couplers are divided, an electrical cable 3001 is connectable to the second coupler while the couplers are connected by the chain. The electrical cable 3001 is shown in Figure 4.

In Figure 2 the inductive coupling 300 is shown with the first coupler 310 connected to the second coupler 320. However, the first coupler 320 is not visible in Figure 2 because the second coupler covers the first coupler 310. There is a first stud 312 in the first coupler 310 which has an exposed surface that is exposed when the first coupler 310 and the second coupler 320 are separated.

There is also a second stud 313 in the first coupler 310 which has an exposed surface that is exposed when the first coupler 310 and the second coupler 320 are separated. The studs 312 and 313 are set in the first coupler 310 such that the exposed surface of the stud is in contact with matching studs 322 and 323 in the second coupler 320. The matching studs 322 and 323 also have an exposed surface. The exposed surfaces of the studs 312 and 313 and the matching studs 322 and 323 are positioned to be in contact when the first coupler 310 is connected to the second coupler 320.

At least one of the studs 312, 313, 322, 323 comprises a permanent magnet. The other studs comprise permanent magnets or ferrous metal. The first and second couplers 310, 320 are held together when connected by the permanent magnet(s). Couplers in other embodiments may be bolted or screwed together. The first and second couplers 310, 320 have first and second ferrous cores 311 , 321 respectively. Exposed faces of poles ferrous cores are visible in Figure 3. Profiles of the ferrous cores 311 , 321 may be seen in Figures 18, 19, 22, 23, 25, and 26.

The first coupler 310 comprises ferrous poles 315, 316, 318. The ferrous poles comprise a portion of a magnetic loop provided by connecting the first coupler 310 to the second coupler 320.

The ferrous poles 315, 316, 318 each have an exposed surface which is exposed when the first coupler is disconnected from the second coupler. The exposed surfaces are interface surfaces between the first coupler 310 and the second coupler 320 when the couplers are connected. The face 318 of the central pole of the first coupler 310 is visible in Figure 3. The faces 315, 316 of the flanking poles of the first coupler are also visible in Figure 3. The flanking poles 315, 316 are located on the flanks of the central pole 318. The face 328 of the central pole of the second coupler 320 is visible in Figure 3. The faces 325, 326 of the flanking poles of the second coupler are also visible in Figure 3.

In Figures 20, 21 , 22, and 23 side views showing the profiles of the ferrous cores 311 , 321 are shown. The ferrous cores are made of laminated ferrous alloy or sintered ferrite powder. Alloy compositions typically comprise iron with cobalt, vanadium, and/or silicon.

Boundaries between laminates and between sintered particles prevent eddy currents which would otherwise reduce the electrical efficiency of the inductive coupling device. Hence the materials the ferrous cores are made from are practically electrically non-conductive over the frequency range of current in the electrical cable 3001. There is a channel 319 intermediate the central poles 318. The channel separates the pole 318 which is centrally located intermediate flanking poles 315, 316. The channel is a groove between the flanking poles 325, 326 on either side of central pole. The channel 319 is arranged to receive the electrical cable 3001 wrapped around the central pole 318.

The second coupler 320 also comprises ferrous poles 325, 326, 328. The ferrous poles comprise a portion of the same magnetic loop which comprises the ferrous poles 315, 316, and 318 in the first coupler when the first and second couplers 310, 320 are connected. The ferrous poles 315, 316, 318, 325, 326, 328 have exposed surfaces. The exposed surfaces of the ferrous poles 315, 316, 318 in the first coupler are arranged to meet face to face with the exposed surfaces of the ferrous poles 325, 326, 328 in the second coupler 320 when the couplers are connected.

A channel 329 in the second coupler 320 surrounds one of the ferrous poles 328 in the second coupler. The channel is a groove between the flanking poles 325, 326 on either side of central pole. The channel 329 is arranged to accept the cable 3001 wrapped around the pole 328. The cable 3001 is shown in Figure 4 wrapped around the cable. The cable can also be seen in the channel in Figure 18 and Figure 19.

Figure 4 shows two of the electrical appliances 1000, 1001 side by side. Electrical cables 3001 , 3002 extend from a power supply 2000. The power supply is arranged to provide an alternating electrical current with constant current amplitude through the cables 3001 , 3002. The cables 3001 , 3002 are arranged to be disconnect-able from the power supply.

There is a convenient method to connect the cable 3001 to the electrical appliances 1000, 1001 , 1002, 1003 and 1004. The first and second coupler 310, 320 are disconnected to wrap the cable around the pole 328. The cable is placed through the entranceway slots 324, 327. The first and second couplers 310, 320 are connected by the studs 312, 313, 322, 323. The connected first and second couplers 310, 320 clamp the cable between them. The cable is wrapped around the pole 328 and then when the couplers 310 and 320 are connected, the cable is held is position wrapped around the pole 328. Figure 5 shows three of the electrical appliances with the couplers of inductive couplings 300, 301 , and 302 connected together.

When the first coupler 310 comes together with the second coupler 320, the face of the central pole of the first coupler 318 is put in register with the face of the central pole 328 of the second coupler to hold the cable 3001 wrapped around the poles. The second coupler comprises a first wall though which the entranceway slots 324, 327 are passages into channel 329, and a second wall on the opposite side of central pole 328 through which entranceway slots 334, 336 are passages into the channel. When the couplers are connected together the entranceway provide passage for the cable into the channel 329. The cable 3001 is placed through entranceway 324 or 327 and can exit through entranceway 336 or 336, or vice versa.

Slot 334 and slot 336 pass through the same side of the non-conductive casing to provide for secured side-by-side passage of two ends of the electrical cable upon connection of the couplers. The slots are open ended with the open end exposed in the same direction as the expose surface of the pole to allow the cable 3001 to be easily attached and also detached by simply pulling the cable 3001 away from pole 328.

In some embodiments, the second coupler comprises a non-conductive casing partially encasing the ferrous alloy or iron from which the poles are formed. The casing forms the wall or a portion of the wall though which the entranceway slots 324, 327, 334, 336 are passages into channel 329.

The channel 329 is formed in the second coupler 320 of out of an core of ferrous material 321 in which are formed the poles 325, 326, 328. The position of each stud 312, 313, 322, 323 is located to orientate the first and second couplers so that the exposed surfaces of the ferrite poles are in matching positions to complete the magnetic loop when the first coupler 310 is connected to the second coupler. When the first and second couplers are connected, the exposed faces of the poles 318, 328 which are surrounded by channels are placed in a matching position forming the magnetic loop.

As shown in Figures 4 and 5 only as single cable 3001 is held to the inductive coupling. Electrical power it transferred inductively from the cable and into magnetic loop by the cable 3001 being wrapped around the pole 328 to provide power to the appliances 1000, 1001 , 1002, 1003, and 1004. Alternatively, power is transferred by both cable 3001 and cable 3002.

Referring again to Figure 3, an alternative is to place cable 3001 through slots 324 and 334 and cable 3002 though entranceway slots 336 and 327 to effectively provide a turn around pole 328. So effectively a turn is provided around the magnetic loop by the two cables 3001 and 3002. Thereby power is inductively transferred to the appliance from both cables through the inductive coupling 300.

The cable 3001 is easily coupled and decoupled from the appliances 1001 , 1002, and 1003. To couple the cable 3001 to the appliance, the cable is simply connecting wrapped a turn around the pole 329 of the second coupler 320 and then the two couplers 310, 320 are connected magnetically by the studs 312, 313, 322, 323. To decouple and release the cable from the appliance, the couplers 310, 320 are simply pulled apart and the cable 3001 removed from the pole.

In one embodiment, the studs 312, 313, 322, 323 are arranged to hold the couplers 310, 320 together with no gap between the exposed surfaces of the poles 315, 316, 318 on the first coupler 310 and the poles 325, 326, 328 on the second coupler. In another embodiment, the exposed surfaces are held apart by the studs so that there is a preselected gap between the exposed surfaces. The preselected gap is such that the amount of power transferable from the cable to the appliance is preselected in accordance with the amount of power required to operate the appliance; the power transferred being reduced by 1/d ² , where d is the gap.

A front view of five appliances 1000, 1001 , 1002, 1003, 1004 coupled to the single cable 3001 is shown in Figure 4. Power from the power supply 2000 is thereby transferable to the appliance. The front of each appliance is arranged to shine light through each lens.

The other cable 3002 extending from the power supply is available to provide power to other appliances since only the single cable 3001 is required to operate the appliances 1000, 1001 , 1002, 1003, and 1004. Both cables 3001 and 3002 can however be used together.

Five appliances 4000, 4001 , 4002, 4003, and 4004 are shown coupled to a single cable 3001 in Figure 7. Figure 7 shows the appliances from a rear view. The appliances 4000, 4001 , 4002, 4003, 4004 comprise inductive coupling 301 , electric converter, and load device.

The inductive coupling 301 for appliance 4000 is the same as the inductive coupling 300 previously described except the magnetic loop is sized to transfer the desired amount of power from the cable 3001 to the load device required to operate the load device. In one embodiment, the load device is a lighting device, in another embodiment the load device is a smoke detector.

In one embodiment, the magnetic loop is properly sized so that the inductive coupling transfers the proper amount of power from the electric cable. It is sized by preselecting the material of the poles, the gap between the exposed surfaces, and the cross section areas of the poles in accordance with the alternating current with constant current amplitude supplied through the cable 3001.

Figure 8 shows another embodiment of four other appliances 5000, 5001 , 5002, 5003 coupled to the single electric cable 3001. Each of the other appliances comprises an inductive coupling 302, electric converter, and load device. In one embodiment of the four other appliances 5000, 5001 , 5002, 5003 the load device is a lighting device, another embodiment the load device is siren, in another embodiment the load device is wireless router. The inductive coupling 302 is arranged to provide the proper amount of power for the load device.

Figure 9 shows an electrical system comprising a power supply 2000 for supplying the alternating current through an electric cable 3001 connected to the power supply. The power supply provides a time average constant current provided as alternating current. The electrical system allows different types of electrical appliances to be coupled to the cable in series. An electrical appliance 1000 of a first type is connected to the cable 3001. A first electrical appliance 4001 of a second type is coupled to the cable. A second electrical appliance 4001 of the second type is coupled to the cable. A first electrical appliance 5001 of a third type 5001 and a second electrical appliance 5002 of the third type are also coupled to the cable.

Each type of electrical appliance requires a power in the form of electrical current having a voltage and current level suitable for that type of device.

The electric cable 3001 is coupled to an inductive coupling 300 of the third type which provides a third preselected voltage and current level to circuitry in appliance 1000.

An inductive coupling 301 of the second type which provides a second preselected voltage and a current level to circuitry in appliances 4000, 4001.

When connected to an inductive coupling 300 of a first type, a third preselected voltage and current level is provided to circuitry of appliance 5001 and of appliance 5002.

The electric cable is coupled to the inductive couplings by a turn around the pole 328 of the second coupler 320 as described for the previous embodiments. Since each inductive coupling 300, 301 , and 302 is arranged to transfer the proper amount of power from the electric cable 3001 to the electrical appliance to which is it fixed. Advantageously, several different appliances are easily provided with the proper amount of power by simply coupling them to single electric cable.

The cost of the electric converter is minimized because the inductive coupling is arranged to transfer a desired amount of power required by the load device to the electric converter. No individual power supply is required for each appliance. There is no need to overdesign the electric converter to take in the full amount of power which the cable can provide for the power supply.

The power supply provided by the power supply will not exceed the amount required to operate the appliances because the amount of power transferable from the cable through the inductive couplings into the couplings is preselected by the couplings. The first coupler 310 is fixed to the electric converter housing 200. The electric converter housing 200 is fixed to the light is fixed to the lighting element 100 or another load device. The permanent magnet of the stud is sized with sufficient magnet strength to support the combined weight of the first coupler, electric housing, and lighting element 100 or another load device. To put the appliance into use a user wraps the cable 3001 around the pole 329 of the second coupler 320 and magnetically attaches the two couplers together. The second coupler is attached to a wall or ceiling.

The first coupler is fixed to a unit 1101 , 4101 , 5101 , 6101 comprising a load device such a light, heater, speaker, router or other load device. The unit is shown in Figures 10 to 15. The unit is housed by housing 200. It is supported by the magnetic connection to the second coupler 320. The unit is thereby suspended from a wall or ceiling or panel to which second coupler 320 is attached. The strength of the magnetic connection between the first and second couplers is sufficient to suspend the weight of the unit.

Figure 10 shows six electrical appliances 1000, 4001 , 4002, 5000, 5002, 5003 coupled by inductive couplings to an electrical cable 3001 connected to a high frequency power supply 2000. The appliances, inductive couplings, and electrical cable operate together in an electrical system. In some embodiments, the electrical cable 3001 is strung inside a building. The cable is placed above a ceiling panel or behind a wall panel in a room. The electrical appliances are fixed to the panel so that the inductive coupling is behind the panel and a light, heater, router, or other useful load projects from the front of the panel.

The power supply comprises two terminals to receive AC electricity. The power supply is arranged to receive AC electricity from an AC mains connection. The power supply is also arranged to receive AC electricity from a DC to AC inverter 2033 which is shown in Figure 10 connected to the two terminals.

The DC to AC inverter 2033 is connected to a photovoltaic panel 2034 which provides DC current to the inverter. In some embodiments, the photovoltaic panel is fixed to the exterior of a building and converts sunlight to electricity.

The electricity which the power supply 2000 provides to the cable 3001 is alternating. The voltage is time varying and alternates. The current is constant amplitude. The voltage alternates in a frequency range of 1 KHz to 1 MHz. The typical optimum frequency for transferring power efficiently through the inductive coupling is 50 KHz. In the embodiments shown in Figures 1 , 2, 3, 4, and 10 the unit comprises a housing 200. Figure 10 shows that the housing 200 encloses the first coupler 310, a transmitter- receiver 540, and a load device 100. Figure 10 also shows that the first coupler 310 is inductively coupled to the second coupler 320. A secondary coil is formed by a turn of the electrical cable 3001 wrapped around a pole in the secondary coupler. 310.

The transmitter-receiver 540 is in an electrical circuit provides current form the first coupler 310 to the load 100. The transmitter-receiver is arranged to receive a wireless signal from a hand-held controller 783 or a mobile device such as a mobile telephone 784 or a computer controller 785 such a tablet or laptop. In some embodiments, the transmitter-receiver 540 comprises an internet router configurable with an IP address and access password.

Figures 11 , 12, 13, 14, and 15 show various arrangements of unit a comprising power transmission circuitry housed inside the housing 200. Each of the electrical appliances comprises two parts which are separable from each other. One of the parts is the second coupler 320. The other of the two parts is a unit 4101 , 4103, 5101 , 6101 within the housing 200.

Shown in Figure 11 shows circuitry comprising a first coupler 310 comprising a coil. The coil is arranged to inductively couple with a coil in the second coupler 320. The coil in the first coupler 310 is electrically connected at two terminals to an AC to DC rectifier 530. The rectifier receives alternating current from the coil which is alternating at the same frequency as the current in the electrical cable 3001. The rectifier is connected in parallel with a capacitor 520. The rectifier and capacitor together provide DC current at two put terminals to a buck inverter 510. The buck inverter is arranged to provide current of a constant value to a load 100. The load 100 is of a type which operates on DC current. The load may be for example a lamp comprising LED lights.

Shown in Figure 12 is circuitry including a first coupler 310 comprising a coil connected by two terminals to a load 100. The load is a type operable on high frequency AC current as the current supplied to the load has the same frequency as current in the electrical cable 3001. Examples of such loads are heating elements and incandescent lamps. Shown in Figure 13 is a first coupler 310 comprising a coil connected at two terminals to an AC to DC rectifier 530. The rectifier is connected by two other terminals to a load 100 to provide rectified current to the load. The load is operable with rectified current with rectified current with a high level of ripple. Shown in Figure 14 is a first coupler comprising a coil connected to two terminals to an AC to DC rectifier 530. The rectifier 530 comprises to another terminal connected to a capacitor 520. The capacitor is connected in parallel with a load 100. The load 100 is a type operable by DC current. The arrangement of the first coupler is preselected so that the level of DC current provided is suitable for the load. The arrangement is provided by a preselected number of turns in the first coupler and/or the area an interface between the first and second couplers, the cross- sectional area in the first coupler of a portion of a magnetic loop formed by connecting the first and second couplers, and/or an interfacial distance between the first and second couplers. The level of current and/or DC voltage is also variable putting one or more turns of the electrical cable on the second coupler 320.

Shown in Figure 15 is circuitry comprising a first coupler 310 comprising a coil. The coil is arranged to inductively couple with a coil in the second coupler 320. The coil in the first coupler 310 is electrically connected at two terminals to an AC to DC rectifier 530. The rectifier receives alternating current from the coil which is alternating at the same frequency as the current in the electrical cable 3001. The rectifier is connected in parallel with a capacitor 520. The rectifier and capacitor together provide DC current at two put terminals to a Buck inverter 511 arranged to step up or step down the level of voltage of DC current provided to load 100. The load 100 is of a type which operates on DC current. Figure 16 shows a unit 1101 which in some embodiments is housed in a housing 200. The unit 1101 comprises a first coupler 310. The unit 1101 is connectable and separable from the second coupler 320. The unit 1101 is a separate part from the second coupler 320.

The unit 1101 comprises a first coupler 310 in communication with a transmitter- receiver 540. The first coupler comprises a coil that is electrically connected by two terminals to a rectifier 530. The rectifier is connected by two other terminals to a load 100. A transmitter-receiver 530 is connected the rectifier by the same two terminals by which the load is connected to the rectifier. The transmitter-receiver is connected by two other terminals the load. The transmitter-receiver 540 is arranged to receive wireless signals. The transmitter-receiver is arranged to control the load based on a signal received. The transmitter-receiver is also arranged to transmit signals on the status of the load and/or power provided by the coil to the load.

Figure 17 shows a unit 1102 which in some embodiments is housed in a housing 200. The unit comprises a first coupler 310 connected by two terminals to a rectifier 530. The rectifier is connected by two other terminals to a transmitter-receiver to provide rectified current to the transmitter-receiver. The transmitter-receiver is connected by third pair of terminals to a buck voltage or current converter which is in turn connected to the load. The load comprises a light 101 , or a C02 detector 105, methane gas detector 106, temperature sensor 102, passive IR sensor 103, or microwave detector and/or transmitter 104.

The second coupler 320 comprises a ferrous core 321 which forms a portion of the ferrous loop. Figure 18 shows a view towards exposed pole faces 325, 326, and 328 of a ferrous core of a coupler 320. The central pole 328 is visible flanked by flanking poles 325, 326. Figure 19 shows a cross section view though the ferrous core 320

The overall outline of the ferrous core is rectangular and the cross section of the central pole is circular.

The first coupler connects to the second coupler with the exposed pole faces of the first and second ferrous cores face to face, thereby forming the ferrous loop .

A collar 377 is fitted around the circular central pole 328 of the ferrous core of the second coupler 320. A turn of cable 3001 wrapped around the collar 3007.

The collar 377 length extends from the floor of the channel 318 along the length of the pole 328. The pole is cylindrical. The collar is a cylindrical hoop and fits loosely over the pole. The collar is rotatable around the central pole.

As Figures 18 and 19 show, in use, a turn of the electrical cable 3001 is wrapped around the collar 377. The turn of the cable 3001 is thereby wrapped around the central pole 328 on the second coupler 320. The turn of the cable 3001 fits in a channel 329. Figure 19 shows a sectional view of second coupler 320. The collar 377 is fitted around the central pole 328.

The turn of the cable 3001 inductively couples the cable to the ferrous block 321 and thereby to the magnetic loop.

The collar rotates easily around the pole. Though not shown in Figure 18 or 19, there is a clearance space between the collar 377 and the central pole 328. The clearance space lets the collar rotate around the central pole with very little friction.

The coupler 320 is moveable along the cable which is wrapped around the collar 377.

Figure 22 shows a schematic of how an appliance comprising the inductive coupling device retains the cable wrapped around the collar.

The collar allows the second coupler to easily slide along the cable when a turn of the cable is wrapped around the central pole. As the coupler moves along the cable, the cable which is wrapped around the collar rotates the collar. The coupler is thereby movable along the cable with little friction. Because of the rotatable collar the appliance itself is movable along the cable while the first and second couplers are connected. There is no need to separate the first and second couplers to move the appliance along the cable 3001. The appliance continues to be inductively connected and operate electrically while the appliance is moved from a first position to a second position and continues to operate electrically at the second position.

It is possible to move the appliance along the entire length of the cable either by moving the appliance along the cable wherein the ends of the cable are fixed or by feeding the cable through the inductive coupling device.

To replace the collar 377 with another collar, the collar 377 is removed from the coupler by sliding the collar 377 past the exposed face of the central pole 328.

Replacing the collar 377 with a collar that is thicker in the diametric direction, increases the distance between the central pose and the cable, thereby reducing the efficiency of the cable wrapped around the collar for electromagnetic induction of with the ferrous core. Hence a user can select the amount of electrical power to be transferred to any appliance by replacing the collar 377 with another collar that is thicker in the diametric direction.

The conductivity of the material from which the collar is formed affects the efficiency of electromagnetic induction between a cable wrapped around the collar and the ferrous core. Hence a user can select the amount of electrical power to be transferred to an appliance by replacing the collar 377 with another collar formed of material with a preselected conductivity.

In some embodiments, a sleeve is fitted over the ferrous core. The sleeve has an internal cross section to conform with the cross section of the ferrous core. The sleeve has an external cross section that is cylindrical and smaller than the diameter of the collar 377. The sleeve is formed from an electrical insulator or has an electrical conductivity pre-selected to transfer a preselected amount of power.

The sleeve fits over ferrous cores of non-circular cross section since the sleeve internal cross section is formed to conform with the cross section the ferrous core. The sleeve and collar in combination allow a cable wrapped around the collar in place on a non-cylindrical ferrous core to rotate the collar as the inductive coupling device is moved along the cable. Hence and appliance comprising an inductive coupling device comprising ferrous cores of non-circular cross section is moveable to any location along the cable.

The sleeve and collar combination used with ferrous cores made from laminated stacks, since the laminated ferrous stacks are most easily made from stamped out ferrous laminates having the profile of the ferrous core.

In use the first coupler 310 is connected to the second coupler 320 which physically and inductively connects the unit 1101 , 1102 comprising the first coupler and load device the electrical cable. The rotatable collar 372 allows the whole unit to slide along the electric cable to which it is coupled. The appliance comprises first coupler 310, the second coupler 320, the load device 100, and circuity for operation of the appliance. The rotatable collar 372 allows the whole appliance to slide along the cable to a new location with ease while remaining physically and inductively coupled to the cable. The first coupler 310 also comprises a block of ferrous material. Connecting the first coupler to the second coupler brings the blocks in the first coupler and the second coupler together. The two blocks provide a ferrous pathway for the magnetic loop which inductively transfers power from the electric cable 3001.

Figure 20 shows a second coupler 320 comprising a block of ferrous material with a cylindrical central pole 328 and a circular channel 329. Figure 20 shows two embodiments wherein the second coupler is connected to the first coupler. In one of the embodiments, the first coupler 310 comprises ferrous block having a central pole intermediate a pair of flanking poles. Connecting the couplers brings an exposed surface the flanking poles of the first coupler into register with an exposed surface of the flanking poles of the second coupler. Connecting the couplers also brings an exposed surface of the central pole in the first coupler into register with an exposed surface of the central pole in the second coupler. The connected couplers form the complete magnetic loop through the couplers for inductively coupling power from the electric cable.

In the other embodiment of connected couplers shown in Figure 20, the first coupler 310 comprises a ferrous block in the form of a rectangular block. The first coupler connects to the second coupler so that the expose surfaces of the flanking poles and central poles on the second coupler are in register with a surface of the rectangular block. The connected couplers form the complete magnetic loop through the couplers for inductively coupling power from the electric cable.

Figure 21 shows two similar embodiments of connected couplers as shown in Figure 20. In the embodiments shown in Figure 21 , the central pole has a square cross- section.

Figure 22 shows an appliance physically and inductively coupled to an electrical cable 3001. The appliance a comprises two separable parts which in Figure 22 are shown connected. One of the separable parts is a second coupler 320. The other of the separable parts is a unit 1103 comprising a first coupler 310, rectifier, and load. In some embodiments, such as shown in Figures 1 , 2, and 3, a housing 200 houses the first coupler, rectifier 530, and load device 100.

The first coupler 310 comprises studs and/or magnets 312, 313. The second coupler also comprises studs and/or magnets 322, 323. The magnets and/or studs are attached to the couplers by fasteners 347.

The studs/magnets in the first coupler pull into register the studs/magnets in the second coupler to hold the first and second coupler together. The magnetic strength of attraction of the magnets to the studs is sufficient to hold the weight of the unit 1103.

The first coupler comprises a ferrous block 311 within a casing. The ferrous block comprises the central pole 318 and flanking poles 316, 318 described for Figures 18, 19, 20, and 21. The first coupler is connected to the housing 200. In some embodiments, the casing of the first couple is an integral part of the housing.

The central pole 318 of the second coupler is aligned with the central pole of the first coupler, and the exposed faces of the couplers are register. The two central poles comprise a portion of the magnetic loop formed by connecting the couplers. A turn 3021 of the cable is wrapped around the central pole 328 of second coupler. The electrical cable 3001 is prevented from coming free of the connected couplers by the aligned poles.

There is a wire with windings 532 around the central pole 318 of the first coupler, so the windings of the wire turn around the magnetic loop so that power is transferred by induction from the electrical cable 3001 to wire. The wire has end which are connected to terminals of a circuit providing power the load device 100. In the embodiment shown in Figure 13 and in Figure 22 the circuit comprises a rectifier 530 and opposite ends of the wire are connected to the rectifier. The rectifier is connected by wires 533 and 534 to the load device 100. In Figure 22 a flexible fastener comprising a chain 400 is connected to the first coupler and the second coupler. In other embodiments, the chain is connected to the housing 200 and the second coupler. The chain holds the second coupler 320 proximate the first coupler when the couplers are separated.

An appliance is shown in Figure 23 which comprises a heatsink 110 for a load device 100 which operates at high temperature such a halogen lamp or a high wattage LED. The first coupler 310 comprises an insulator which separates the ferrous block 321 from the heat sink. The ferrous block 321 is thereby prevented from being raised to the correct temperature so that the magnetic loop continues to operate efficiently. The first coupler is attached to a surface of the heat sink and the load is attached to a distal surface of the heat sink. The heat sink maintains the temperature of the first coupler below a preselected temperature. The ferrous block operates efficiently as a portion of the magnetic loop below the preselected temperature. The appliance shown in Figure 23 has an exterior shape which is elongate. To install the appliance, the narrow dimension of the elongate shape is inserted through an aperture in a panel in a ceiling.

The load device has a flange around its circumference. The flange is supported by a bezel 107 connected to the panel. The appliance is thereby supported by bezel. A spring lever 109 is attached to a hinge which connects the bezel to the panel. The spring lever assists rotating the bezel away from the flange so that the appliance device is easily installed in or removed from the aperture in the panel.

The inductive coupling describe herein operates under water whether fresh water or salt water. The electric cable 3001 is sheathed and so prevented from exposure to the water. Power is inductively drawn from the cable into the coupling so current is not shorted from the cable or the coupling to the water.

In some embodiments, the second coupler 320 comprises glands for the entranceways 327 and 334. The cable 3001 is protected in protective sheath and which goes through the gland to prevent spark or arcing in a hazardous environment.

Figure 24 shows schematic of rail 9050 supporting the second coupler 320. The electric cable 3001 is arranged along the rail.

The second coupler is arranged to slide along the rail. In an embodiment, the collar 377 shown in Figure 18 and 19 is arranged to roll along the rail. The rail allows the appliance to be easily moved to various locations by sliding along rail. The second coupling comprises a lock screw for fixing the coupling to a position along the rail.

Figure 25 shows a view in detail of the inductive coupling device carrying an appliance 1000 on a rail 9050. Figure 26 shows a view in detail of the collar 377 intermediate the rail 9050 and the rail 9050 to support the electrical appliance 1000 on the rail.

The rotational axis of the collar 377 is perpendicular to the long axis of the rail 9050 for the collar to roll along the length of the rail.

The cable 3001 is sheathed so that there can be no inadvertent shorting to the rail or a person attaching the appliance 1001 to the rail 9050. The cable 3001 is suspended between the ends of the rail and extends along the length of the rail.

A turn 3021 of the cable 3001 is wrapped around the collar 377. The collar 377 encircles the central pole 328 of the ferrous core in the second coupler. The collar 377 encircles the central pole 328 of the ferrous core is in the first coupler and the collar rests on the rail, so that the second coupler is movable along the rail with very little friction as the collar rollers on the rail.

The first coupler 310 is partly contained in the housing 200 of the appliance. The first coupler is physically and inductively joined to the appliance. The first coupler is physically and inductively joined to the appliance. The first coupler is connected to the second coupler with the ferrous cores of the first and second couplers are arranged into a ferrous loop.

An extension 331 , 332 from the flanking pole or the central pole of the ferrous core of the second coupler extends under the connected flanking or central pole of the first coupler to support the weight of the appliance. Alternatively, the weight of the appliance may be supported by the magnetic stud 347 connection described above.

The appliance rolls along the rail on the collar drawing power from the cable safely, quietly, reliably, and easily. The relative strength of the rail compared to cable means that a thin flexible cable is used which is ideally suited for turning around the collar as the appliance is moved.

The invention has been described by way of examples only. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the claims. List of Features Annotated in Figures

100 load, illumination device

101 load - light

102 load - temperature sensor

103 load - passive I R sensor

104 load - microwave transmitter/receiver

105 load - C02 sensor

106 load - methane gas sensor

108 load - halogen lamp

110 load - heat sink

117 bezel

119 spring lever for rotating bezel

200 housing

300 inductive coupling

301 inductive coupling for appliance of the second type

302 inductive coupling for appliance of the third type

310 first coupler

311 ferrous block of first coupler

312 stud in first coupler

313 second stud in first coupler

315 ferrous pole flanking central pole in first coupler

316 ferrous pole flanking central pole in first coupler

318 ferrous pole, central pole intermediate flanking poles in first coupler

319 channel around central pole in first coupler

320 second coupler

321 ferrous block of second coupler

322 matching stud in second coupler to match stud 312 in first coupler

323 matching stud in second coupler to match second stud 313 in first coupler

324 slot through first wall of second coupler to channel

325 ferrous pole flanking central pole in second coupler

326 ferrous pole flanking central pole in second coupler

327 slot through first wall of second coupler to channel of second coupler

328 ferrous pole, central pole intermediate flanking poles in second coupler

329 channel around central pole in second coupler

334 slot through second wall of second coupler to channel

336 slot through second wall of second coupler to channel

347 fastener attaching magnet and/or stud to coupler 377 collar fitted around central pole

400 chain

510 buck inverter constant current

511 buck inverter step up / step down voltage

530 rectifier

532 turns of wire around the central pole of the first coupler

533 first wire connecting rectifier to load device

534 second wire connecting rectifier to load device

540 transmitter- receiver

783 hand held controller

784 mobile phone

1000 electrical appliance of a first type comprising an inductive coupling

1001 second electrical appliance of the first type

1002 third electrical appliance of the first type

1003 fourth electrical appliance of the first type

1004 fifth electrical appliance of the first type

1101 unit comprising fi rst coupler and load

1102 unit comprising fi rst coupler, converter, and load

1103 unit comprising fi rst coupler, rectifier, and load

1104 unit comprising fi rst coupler, rectifier, transmitter-receiver, and load

1105 unit comprising fi rst coupler, rectifier, transmitter-receiver, inverter, and load

2000 power supply

2033 DC to AC inverter to intermediate DC power source and AC power supply

2034 photovoltaic panel for power supply

3001 electrical cable connected to power supply

3002 second electrical cable connected to power supply

3021 turn of electric cable around central pole

4000 electrical appliance of a second type comprising an inductive coupling

4001 second electrical appliance of the second type

4002 third electrical appliance of the second type

4003 fourth electrical appliance of the second type

4004 fourth electrical appliance of the second type

4101 unit comprising first coupler and load for appliance

5000 electrical appliance of a third type comprising an inductive coupling

5001 second electrical appliance of the third type

5002 third electrical appliance of the third type 5003 fourth electrical appliance of the third type

5101 unit comprising first coupler and load for appliance

9050 rail