NL2025842B1

NL2025842B1 - Lighting system and self stabilizing inductive power supply device thereof

Info

Publication number: NL2025842B1
Application number: NL2025842A
Authority: NL
Inventors: De Angelis Jimmy
Original assignee: Schreder Sa
Priority date: 2020-06-16
Filing date: 2020-06-16
Publication date: 2022-02-16

Abstract

A lighting system comprising: a power supply generating electrical power provided to a primary wire forming a current loop, including a switching amplifier supplied in power outputting the electrical power to the primary wire based on an input signal; a feedback loop connected to the switching amplifier; a lighting module receiving power from the power supply. The feedback loop comprises: a current sensing means coupled to the primary wire outputting a feedback signal; a controlling means outputting a first waveform signal based on the feedback signal, the first waveform signal being provided as the input signal. The lighting module comprises: an electromagnetic coupling means comprising a magnetic core receiving the current loop, and a secondary wire wound around a portion of the magnetic core coupling inductively to the primary wire; a light source connected to the secondary wire, the electromagnetic coupling means supplying current to the light source.

Description

LIGHTING SYSTEM AND SELF STABILIZING INDUCTIVE POWER SUPPLY DEVICE THEREOF

FIELD OF INVENTION The field of the invention relates to lighting systems, preferably for outdoor lighting or industrial lighting. Particular embodiments relate to a lighting system, and an inductive power supply device for use in a lighting system.

BACKGROUND Domestic lighting system which are supplied in power via an inductive power supply device are well known but do not have a technology which is well adapted for modularity or changing lighting environment, such as in outdoor lighting or industrial lighting for example, due to the differences in constraints in terms of characteristics of the lighting provided in a demanding environment, or in terms of the infrastructure providing power. Typically, the inductive domestic lighting systems are developed based on aesthetical considerations and forego more practical considerations.

In particular, one of the aspects which is not transposable to a demanding environment from domestic lighting systems is an adaptive power supply. Indeed, the environment indoors is controlled, with a fixed shape, and risk-free, and the domestic lighting systems have generally a fixed design with constant supplying characteristics. This type of design is not suited where modularity and adaptability are parameters to take into account.

SUMMARY The object of embodiment of the invention is to provide a lighting system and an inductive power supply device allowing for a modular and user-friendly installation, and with a stable intensity of the light emitted. Such lighting system and inductive power supply device are advantageous for a number of applications, e.g. temporary lighting, events lighting, modular lighting, and environments, e.g. outdoor environment, industry halls, warehouses, construction sites.

According to a first aspect of the invention, there is provided a lighting system, preferably for outdoor lighting or industrial lighting. The lighting system comprises a power supply, a feedback loop, and at least one lighting module. The power supply is configured for generating electrical power provided to a primary wire forming a current loop. The power supply includes a switching amplifier being supplied in power, and the switching amplifier is configured for outputting the electrical power to the primary wire based on a signal input. The feedback loop is connected to the switching amplifier. The feedback loop comprises: a current sensing means coupled to the primary wire and configured for outputting a feedback signal based on the current sensed in the primary wire; a controlling means, preferably a microcontroller, configured for outputting a first waveform signal based on the feedback signal; and the first waveform signal is provided as an input signal to the switching amplifier. The at least one lighting module is configured for receiving power from the power supply. The at least one lighting module includes an electromagnetic coupling means, and at least one light source. The electromagnetic coupling means comprises: a magnetic core configured for receiving the current loop of the primary wire; and a secondary wire wound around a portion of the magnetic core and configured for coupling inductively to the primary wire. The at least one light source, preferably a light emitting diode, is connected to the secondary wire. The electromagnetic coupling means is configured for supplying current to the at least one light source. In the lighting system according to the invention, the power supply provides AC power to the primary wire. The at least one lighting module receives the AC power from the primary wire via the secondary wire due to the electromagnetic induction phenomenon using the magnetic core of the electromagnetic means.

Since the power is supplied to the at least one lighting module using the electromagnetic induction phenomenon, there is no need for a physical coupling between the power supply and the at least one lighting module using wires for example. Thus, the at least one lighting module may be easily installed and positioned without complex electrical wiring required. It contributes to a high modularity of the system in terms of installation, while installing as well as after installation. For example, depending on the implementation of the system, additional lighting modules may easily be provided to the lighting system and the at least one lighting module may be displaced to light another area neighboring the lighting system.

By using a switching amplifier, the power may be more efficiently supplied to the primary wire with less waste by heat emission. Additionally, the switching amplifier may allow for an improved reactivity of the power supplied as well as an improved modularity with respect to an addition or subtraction of a lighting module, as well as being substantially insensitive to noise. By providing a feedback loop connected to the switching amplifier, the power supplied to the primary wire may be regulated. In an embodiment, the feedback loop is configured for obtaining a constant AC current supply, in amplitude and frequency, through the primary wire independently of a load of the primary wire. In doing so, no driver is needed within the lighting system due to the characteristics of the power delivery. The lighting system may be adapted for outdoor lighting or industrial lighting. By outdoor lighting and industrial lighting, it is meant lighting adapted for roads, tunnels, industrial plants, stadiums, airports, harbors, rail stations, campuses, parks, cycle paths, pedestrian paths, or pedestrian zones for example, and industrial and outdoor lighting systems can be used notably for the lighting of an outdoor area, such as roads and residential areas in the public domain, private parking areas and access roads to private building infrastructures, warehouses, industry halls, etc.

According to a preferred embodiment, the at least one lighting module further includes a current converting means, preferably a rectifier, configured for converting an AC current from the secondary wire to a DC current supplied to the at least one light source.

In this manner, the at least one lighting module may comprise a connected DC load. In an embodiment, the current converting means may be a full-wave bridge rectifier. According to an exemplary embodiment, the at least one lighting module further includes an inductor element connected in series between the electromagnetic coupling means and the current converting means. Because current converting means may be highly nonlinear components, the current converting means may introduce high frequency harmonics in the AC current waveform of the primary wire. These high frequency harmonics may increase as there is more lighting modules coupled to the primary wire. By adding an inductor element in series between the electromagnetic coupling means and the current converting means, the high frequency harmonics introduced may be reduced in the primary wire without substantially affecting the power factor. According to a preferred embodiment, the lighting system further comprises at least two, preferably at least three, more preferably at least four lighting modules. In this way, the modularity of the lighting system is improved and a single power supply may be needed to provide power for a plurality of light sources.

According to an exemplary embodiment, the at least one lighting module further includes a heat dissipation element, preferably configured for dissipating heat from the current converting means.

In this manner, heat dissipation by the at least one lighting module may be better managed. According to a preferred embodiment, the power supply further comprises: - astep-down converter, preferably a buck converter; - a switching means, preferably a relay, coupled to said step-down converter; and - wherein the switching amplifier is supplied in power by the step-down converter. In this way, the power provided from an electrical grid, for example, may be adapted for powering a lighting system with a substantially low power consumption. The switching means may be used for controlling whether there is supply of power to the lighting system.

According to an exemplary embodiment, the at least one light source of the at least one lighting module is an OLED or a QLED.

In this manner, one can obtain light emitted from the at least one lighting module with a high intensity, suitable for providing a desired visibility level in a given environment, for example in an outdoor environment, while having a substantially low power consumption. In an embodiment, there may be more than one light source per lighting module.

According to a preferred embodiment, the feedback loop further comprises at least one filter circuit, preferably an LC filter circuit, said at least one filter circuit configured for converting the first waveform signal into a second waveform signal.

In this way, characteristics of the first waveform signal may be modified in order to serve as an input signal to the switching amplifier. The characteristics of the first waveform signal that can be modified may be an amplitude, a frequency, and/or a waveform shape of the first waveform signal. For example, the first waveform signal outputted by the microcontroller may be a square waveform signal, and the at least one filter circuit may convert the first waveform signal into a second waveform signal with the same frequency and amplitude but sinusoidal. In another embodiment, the first waveform signal is directly usable as the input signal to the switching amplifier and there is no need for the at least one filter circuit.

According to an exemplary embodiment, the feedback loop further comprises: - an adjustable voltage means, preferably a potentiometer, connected between the controlling means and the switching amplifier, controlled by the controlling means,

and configured for outputting a third waveform signal based on an inputted waveform signal, such that an amplitude of the third waveform signal is below a predetermined level, - wherein the adjustable voltage means output is configured for providing the input 5 signal to the switching amplifier.

In this manner, the controlling means of the feedback loop may control the adjustable voltage means to increase or decrease an amplitude of the third waveform signal until a desired current in the primary wire is reached. By using such a control, the AC current in the primary wire may be stabilized with constant characteristics independently of the load of the at least one lighting module. In an embodiment, the feedback loop comprises the adjustable voltage means and the at least one filter circuit, said at least one filter circuit being connected in series between the controlling means and the adjustable voltage means.

According to a preferred embodiment, the controlling means is configured for controlling the adjustable voltage means to output a substantially low voltage, upon detection of an absence of current by the feedback loop.

In this way, the amplitude of the third waveform signal serving as the input signal to the switching amplifier may be limited to a safe value, thereby preventing the switching amplifier for outputting power to the primary wire that could electrically damage the at least one lighting module. According to an exemplary embodiment, the input signal has a frequency above 20kHz.

In this manner, the signal is above a frequency audible by a human being.

According to a preferred embodiment, the secondary wire of the electromagnetic coupling means has less than 40 windings, preferably less than 30 windings, more preferably less than 20 windings, most preferably less than 10 windings.

In this way, the at least one lighting module may operate at a substantially high frequency, preferably above a frequency audible by a human being. In an embodiment, the AC current circulating in the primary wire may have a frequency above 20kHz and the number of windings of the secondary wire around the magnetic core may be reduced in order to operate at a higher frequency corresponding to the frequency of the power in the primary wire.

According to a preferred embodiment, the apparent supplied power through the primary wire is below OW. In this manner, a lighting system with low power consumption may be realized. In an embodiment, the at least one light source is an OLED or a QLED light source which is adapted for being supplied with an amount of power below 9W. According to an exemplary embodiment, the lighting system further comprises at least one functional module configured for receiving power from the power supply by inductive coupling. In this way, additional functions may be provided to the lighting system which gains in modularity. There may be one function added per functional module, or one functional module may comprise a plurality of functions. For example, the functional module may be any one of: a display module, an antenna module, a sensing module, a speaker module, an air cleaning module such as a UV light source, etc. The sensing module may comprise a pollution sensor, a motion sensor, a humidity sensor, a light sensor, a temperature sensor, a visibility sensor, an image capturing sensor, a radar sensor, a sound sensor, a voice recorder, a CO2 sensor, a NOx sensor, a SOx sensor, a smoke sensor, a biological threat sensor, an infrared sensor, a thermal sensor. It is to be noted that the at least one lighting module may also comprise additional functions similar to the ones described with respect to the functional modules in addition to a lighting function. The skilled person will understand that the hereinabove described technical considerations and advantages for lighting system embodiments also apply to the below described corresponding inductive power supply device embodiments, mutatis nutandis.

According to a second aspect of the invention, there is provided an inductive power supply device for use in a lighting system. The inductive power supply device comprises: - a power supply configured for generating electrical power provided to a primary wire forming a current loop, including: - a switching amplifier being supplied in power, - wherein the switching amplifier is configured for outputting the electrical power to the primary wire based on an input signal, - a feedback loop connected to the switching amplifier, comprising: - a current sensing means coupled to the primary wire and configured for outputting a feedback signal based on the current sensed in the primary wire,

- acontrolling means, preferably a microcontroller, configured for outputting a first waveform signal based on the feedback signal, - wherein the first waveform signal is provided as the input signal to the switching amplifier.

According to an exemplary embodiment, the power supply further comprises: - a step-down converter, preferably a buck converter; - a switching means, preferably a relay, coupled to said step-down converter; and - wherein the switching amplifier is supplied in power by the step-down converter.

According to a preferred embodiment, the feedback loop further comprises: - at least one filter circuit, preferably an LC filter circuit, said at least one filter circuit configured for converting the first waveform signal into a second waveform signal. According to an exemplary embodiment, the feedback loop further comprises: - an adjustable voltage means, preferably a potentiometer, connected between the controlling means and the switching amplifier, controlled by the controlling means, and configured for outputting a third waveform signal based on an inputted waveform signal, such that an amplitude of the third waveform signal is below a predetermined level, - wherein the adjustable voltage means output is configured for providing the input signal to the switching amplifier.

BRIEF DESCRIPTION OF THE FIGURES This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing a currently preferred embodiment. Like numbers refer to like features throughout the drawings. Figure 1 shows schematically an exemplary embodiment of a lighting system according to the invention; Figure 2 shows schematically another exemplary embodiment of a lighting system according to the invention; Figure 3 illustrates an electronic circuit of an exemplary embodiment of a lighting system according to the invention.

DESCRIPTION OF EMBODIMENTS Figure 1 shows schematically an exemplary embodiment of a lighting system according to the present invention. The lighting system 100 comprises a power supply 110, a feedback loop comprising a current sensing means 120 and a controlling means 130, and at least one lighting module 150.

The lighting system 100 may be adapted for outdoor lighting or industrial lighting. By industrial and outdoor lighting, it is meant lighting adapted for roads, tunnels, industrial plants, stadiums, airports, harbors, rail stations, campuses, parks, cycle paths, pedestrian paths, or pedestrian zones for example, and outdoor and industrial lighting systems can be used notably for the lighting of an outdoor area, such as roads and residential areas in the public domain, private parking areas and access roads to private building infrastructures, warehouses, industry halls, constructions sites, etc.

The power supply 110 is configured for generating electrical power provided to a primary wire 140 forming a current loop. The power supply comprises a switching amplifier 111. The switching amplifier 111 is configured for outputting the electrical power to the primary wire 140 based on an input signal. The input signal is originating from the feedback loop. The teedback loop may generate a feedback signal 121 using the current sensing means 120. The current sensing means 120 may be configured for sensing the current going through the primary wire 140. The current sensing means 120 may comprise any one, or a combination, of the following: an operational amplifier, a resistor, an active rectifier circuit, an inductance, a capacitance.

After being generated by the current sensing means 120, the feedback signal may be sent to the controlling means 130. In an embodiment, the controlling means 130 may be a microcontroller. The controlling means 130 is configured for outputting a first waveform signal 131 based on the feedback signal. The first waveform signal 131 may be characterized by a first amplitude, a first frequency, and/or a first waveform shape, e.g. sinusoidal, triangular, square. In the embodiment of Figure 1, the first waveform signal 131 is the input signal of the switching amplifier 111. The first waveform signal 131 may be a sinusoidal signal.

Based on the input signal, the switching amplifier 111 may output power going through the primary wire 140. The switching amplifier 111 may output through the primary wire 140 an alternating current signal amplified relative to the primary wire 140. In the embodiment of Figure I, the first waveform signal 131 may be a sinusoidal current signal, and the switching amplifier 111 may output an amplified sinusoidal current signal with the same frequency as the first frequency of the first waveform signal 131. In an embodiment, the first frequency, that is the frequency of the input signal, may be above 20kHz.

The power generated through the primary wire 140 may be received by the at least one lighting module 150. In an embodiment, there may be at least two, preferably at least three, more preferably at least four lighting modules 150. The at least one lighting module 150 comprises an electromagnetic coupling means including a magnetic core 151 and a secondary wire 152, and at least one light source 153. The magnetic core 151 is configured for receiving the current loop of the primary wire 140. The secondary wire 152 is wound around a portion of the magnetic core 151 and is configured for coupling inductively to the primary wire 140.

The magnetic core 151 may be made of iron. Typically, the magnetic core 151 is cylindrically-shaped with a trough-hole as seen in the direction of the magnetic core main axis, via which the primary wire 140 is passing through. The electromagnetic coupling means may allow to supply power to the at least one light source 153. In an embodiment, there may be more than one light source 153 being supplied in power by the electromagnetic coupling means.

In a preferred embodiment, the at least one lighting module 150 comprises a low power light source 153 such as a LED light source, an OLED light source, or a QLED light source.

Correspondingly, the apparent power provided through the primary wire 140 may be below 9W.

In an embodiment, the lighting system 100 may further comprise at least one functional module {not shown) configured for receiving power from the power supply by inductive coupling. There may be one function added per functional module, or one functional module may comprise a plurality of functions. For example, the functional module may be any one of: a display module, an antenna module, a sensing module, a speaker module, an air cleaning module such as a UV light source, etc. The sensing module may comprise a pollution sensor, a motion sensor, a humidity sensor, a light sensor, a temperature sensor, a visibility sensor, an image capturing sensor, a radar sensor, a sound sensor, a voice recorder, a CO2 sensor, a NOx sensor, a SOx sensor, a smoke sensor, a biological threat sensor, an infrared sensor, a thermal sensor. It is to be noted that the at least one lighting module 150 may also comprise additional functions similar to the ones described with respect to the functional modules in addition to a lighting function.

To enhance the coupling efficiency between the primary wire 140 and the electromagnetic coupling means of the at least one lighting module 150, the secondary wire 152 may be wound around the magnetic core 151 such that there is a match in the frequency with current frequency of the primary wire 140. In an embodiment, the frequency to be matched is about 22kHz and the secondary wire 152 is wound 10 times around the magnetic wore 151.

The at least one lighting module 150 may also be provided with a heat dissipation element (not shown) in order to prevent the at least one lighting module 150 from overheating.

Figure 2 shows schematically another exemplary embodiment of a lighting system according to the present invention. The lighting system 100 comprises a power supply 110, a feedback loop comprising a current sensing means 120 and a controlling means 130, and at least one lighting module 150. Common elements between the embodiments of Figure 1 and Figure 2 have similar functions and features and will not be described again for convenience-sake.

In the embodiment of Figure 2, the power supply 110 may also comprise a switching means 112 and a step-down converter in addition to a switching amplifier 111. The step-down converter 113 may be a buck converter.

The step-down converter 113 may be configured for outputting power with a reduced voltage amplitude compared to a voltage amplitude of an inputted power.

By doing so, the outputted voltage amplitude of the step-down converter 113 may be better adapted to supply the other electronic components of the lighting system 100. In an embodiment, there may be more than one step-down converter 113 adapted to supply power at different voltage amplitudes to various electronic components of the lightmg system 100. The switching means 112, preferably a relay, may be adapted to allow the provision of power to the switching amplifier 111. In another embodiment, additional switching means 112 may be included in the lighting system 100 between the power supply and the corresponding electronic component being supplied.

The lighting system 100 of Figure 2 may comprise two lighting modules 150. The skilled person will understand that such a number of lighting modules 150 is not limitative and that more or less lighting modules 150 may be arranged on a primary wire 140 of the lighting system 100. Each of the lighting module 150 may comprise an electromagnetic coupling means including a magnetic core 151 and a secondary wire 152 wound around the magnetic core 151, and atleast one light source 153. The lighting modules 150 may also comprise a current converting means 154. The current converting means 154, preferably a rectifier, a full-wave bridge rectifier in the embodiment of Figure 2, may be configured for converting an AC current from the secondary wire 152 to a DC current supplied to the at least one light source 153. The current converting means 154 coupled in parallel with the at least one light source 154 may be helped by a capacitance 156 coupled in parallel in order to smooth out the power provided by the current converting means 154. The at least one light source 153 may be an LED light source, an OLED light source, or a QLED light source.

Additionally, a heat dissipation element (not shown) may be provided to the current converting means 154. The at least one lighting module 150 may further include an inductor element 155 connected in series between the magnetic core 151 of electromagnetic coupling means and the current converting means 154. Because current converting means 154 may be highly nonlinear components, the current converting means 154 may introduce high frequency harmonics in the AC current waveform of the primary wire 140. These high frequency harmonics may increase as there are more lighting modules 150 coupled to the primary wire 140. By adding the inductor element 155 in series between the electromagnetic coupling means and the current converting means 154,

the high frequency harmonics introduced may be reduced in the primary wire 140 without substantially affecting the power factor.

In the embodiment of Figure 2, the feedback loop, in addition to the current sensing means 120 and the controlling means 130, may also comprise an adjustable voltage means 160. The adjustable voltage means 160, preferably a potentiometer, may be connected between the controlling means 130 and the switching amplifier 111. The adjustable voltage means 160 may be controlled by the controlling means 130 via a control signal 132. The adjustable voltage means 160 may be configured for outputting a third waveform signal 161 based on an inputted waveform signal 171, such that an amplitude of the third waveform signal 161 is below a predetermined level.

In the embodiment of Figure 2, the adjustable voltage means 160 is configured for providing an input signal to the switching amplifier 111, in other words the input to the switching amplifier 111 corresponds to the third waveform signal 161. Additionally or alternatively to the adjustable voltage means 160, the feedback loop may also comprise at least one filter circuit 170. The at least one filter circuit 170, preferably at least one LC filter circuit, may be configured for converting the first waveform signal 131 into a second waveform signal 171. In the embodiment of Figure 2, the at least one filter circuit 171 is coupled in series between the controlling means 130 and the adjustable voltage means 160, and the second waveform signal 171 is being inputted to the adjustable voltage means 160. The feedback loop of the lighting system 100 aims at aiding the switching amplifier 111 in supplying the power through the primary wire 140 in a stabilized manner by providing the input signal, the third waveform signal 161 in Figure 2, to the switching amplifier 111 based on a feedback signal 121. The feedback signal 121 is outputted by the current sensing means 121. Based on the characteristics of the feedback signal 121, the controlling means 130 outputs the first waveform signal 131. The first waveform signal 131 may be characterized by a first amplitude, a first frequency, and/or a first waveform shape.

Similarly, the second waveform signal 171 may be characterized by a second amplitude, a second frequency, and/or a second waveform shape; and the third waveform signal 161 may be characterized by a third amplitude, a third frequency, and/or a third waveform shape.

The power outputted by the switching amplifier 111 may take the shape of an amplified sinusoidal signal.

The amplitude of the outputted amplified sinusoidal signal may be adapted to the electrical characteristics of the at least one lighting module 150. Similarly, the frequency of the outputted amplified sinusoidal signal may be adapted to the electrical characteristics of the at least one lighting module 150. The amplification may take the form of an amplification in amplitude of the input signal to the switching amplifier.

So, the third waveform signal 161 may have a matching waveform shape and a matching frequency with the outputted amplified sinusoidal signal by the switching amplifier.

The third amplitude of the third waveform signal 161 may be controlled by the controlling means 130 via the control signal 132 to take into account the amplification capabilities of the switching amplifier.

The first waveform shape of the first waveform signal 131 may be a shape different than a sinusoidal waveform, for example a triangular waveform or a square waveform. So, the at least one filter circuit 170 may be configured for removing high frequency components of the first waveform signal 131 in order to obtain the second waveform signal 171 as a sinusoidal waveform; the second amplitade of which being adjusted by the adjustable voltage means 160 in order to obtain the third waveform signal 161.

Figure 3 illustrates an electronic circuit of an exemplary embodiment of a lighting system according to the present invention. The lighting system 100 comprises a power supply (not shown), a feedback loop comprising a current sensing means 120 and a controlling means 130, and at least one lighting module 150.

In the embodiment of Figure 3, the power supply may include a switching amplifier 111, a first step-down converter 113° and a second step-down converter 113”. The first step down- converter 113’ may be configured for converting a first voltage amplitude from -45V/+45V to a second voltage amplitude corresponding to -15V/+15V. The second step-down converter 113” may be configured for converting the second voltage amplitude at -15V/+15V to a third voltage amplitude corresponding to OV/+5V. The first voltage amplitude may be used for supplying power to an operational amplifier of the switching amplifier 111. The second voltage amplitude may be used for supplying power to an operational amplifier of the current sensing means 120. The third voltage amplitude may be used for supplying power to a microcontroller of the controlling means 130, and to a potentiometer of an adjustable voltage means 160.

The switching amplifier 111 of Figure 3 is a class D audio amplifier. The switching amplifier 111 is configured for supplying power to a primary wire 140. The at least one lighting module 150 is inductively coupled to the primary wire 140. The coupling is achieved by an electromagnetic means including a magnetic core 151 and a secondary wire 152. The at least one lighting module 150 may comprise a rectifier 154 configured for converting an AC current into a DC current, helped by a capacitance 156 connected in parallel to smooth out the current outputted by the rectifier, thereby supplying LED light source 153.

The primary wire 140 may form a current loop. A resistance part of the current sensing means 120 and connected in series with the primary wire 140 may provide an input signal to an active rectifier circuit 123 of the current sensing means. The active rectifier circuit 123 may output a feedback signal 121 to the controlling means 130.

In the embodiment of Figure 130, the controlling means 130 may output a 23kHz square waveform signal as a first waveform signal 131, as well as a control signal 132 to control the adjustable voltage means 160. The first waveform signal 131 may be converted into a 23kHz sinusoidal waveform signal as a second waveform signal 171 by a plurality of LC filter circuits

170. The second waveform signal 171 may be fed to the adjustable voltage means 160 before being outputted as an input signal to the switching amplifier 111.

Whilst the principles of the invention have been set out above in connection with specific embodiments, it is to be understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims.

Claims

Conclusions

A light system, comprising: - a power source (110) arranged to generate electrical power to be supplied to a primary wire (140) forming a current loop, comprising: - a switching amplifier (111) being powered, - wherein the switching amplifier (110) is adapted to output the electrical power to the primary wire (140), based on an input signal, - a feedback loop connected to the switching amplifier (111), comprising: - a current sensing means (120) coupled to the primary wire (140) and arranged to output a feedback signal (121) based on the sensed current in the primary wire (140), a control means (130), preferably a microcontroller, adapted to output a first waveform signal (131) based on the feedback signal (121), - wherein the first waveform signal (131) is provided as the input signal to the switching amplifier (111), - at least one light module (150 ) arranged to receive power from the power source (110), comprising: - an electromagnetic coupling means comprising: - a magnetic core (151) adapted to receive the current loop of the primary wire (140), - a secondary wire (152) wrapped around a portion of the magnetic core (151) and arranged to be inductively coupled to the primary wire (140), - at least one light source (153), preferably a light emitting diode, connected to the secondary wire (152), - wherein the electromagnetic coupling means is adapted to supply power to the at least one light source (153).

The light system of claim 1, wherein the at least one light module (150) further comprises a current converting means (154), preferably a rectifier, adapted to convert an AC current from the secondary wire (152) to a DC power supplied to the at least one light source (153).

The light system of the preceding claim, wherein the at least one light module (150) further includes an inductor element (155) connected in series between the electromagnetic coupling means and the current converting means (154).

The light system according to any one of the preceding claims, further comprising at least two, preferably at least three, even more preferably at least four Light modules (150).

The light system of any one of claims 2-4, wherein the at least one light module (150) further includes a heat dissipation element, preferably arranged to dissipate heat from the power conversion means (154).

The light system according to any one of the preceding claims, wherein the power source (110) further comprises: - a step-down converter (113), preferably a buck converter; - a switching means (112), preferably a relay, coupled to the step-down converter (113); and - wherein the switching amplifier (111) is powered by the step-down converter (113).

The light system of any preceding claim, wherein the at least one light source (153) of the at least one light module is an OLED or a QLED.

The light system of any preceding claim, wherein the feedback loop further comprises: at least one filter circuit (170), preferably an LC filter circuit, the at least one filter circuit (170) adapted to transform the first waveform signal (131) into a second waveform signal (171).

The light system according to any one of the preceding claims, wherein the feedback loop further comprises: - an adjustable voltage means (160), preferably a potentiometer, connected between the control means (130) and the switching amplifier (111), which is controlled by the control means ( 130) is controlled, and is arranged to output a third waveform signal (161) based on an input waveform signal so that an amplitude of the third waveform signal (161) is below a predetermined level, the output of the adjustable voltage means is arranged to provide the input signal to the switching amplifier {111).

The light system of any preceding claim, wherein the control means (130) for controlling the adjustable voltage means (160) is arranged to output a substantially low voltage upon detection of a current absence in the feedback loop.

The light system of any preceding claim, wherein the input signal has a frequency above 20 kHz.

The light system of any preceding claim, wherein the secondary wire (152) of the electromagnetic coupling means has less than 40 turns, preferably less than 30 turns, even more preferably less than 20 turns, most preferably less than 10 turns. windings.

The light system of any preceding claim, wherein the apparent power delivered through the primary wire (140) is less than 9W.

The light system of any preceding claim, further comprising at least one functional module configured to receive power from the power source (110) via an inductive coupling.

An inductive power source device for use in a light system, comprising: - a power source (110) adapted to generate electrical power supplied to a primary wire (140) forming a current loop, comprising: - a switching amplifier (111) which is powered, - the switching amplifier (111) being adapted to output the electrical power to the primary wire (140), based on a feed signal, - a feedback housing connected to the switching amplifier (111), comprising : - a current sensing means (120) coupled to the primary wire (140) and arranged to output a feedback signal (121) based on the sensed current in the primary wire (140),

- a control means (130), preferably a microcontroller, arranged to output a first waveform signal (131) based on the feedback signal (121), - wherein the first waveform signal (131) is applied as the input signal to the switching amplifier (111) provided.

The inactive power source device according to the preceding claim, wherein the power source (110) further comprises: - a step-down converter (113), preferably a buck converter; - a switching means (112), preferably a relay, coupled to the step-down converter (113); and - wherein the switching amplifier (111) is powered by the step-down converter (113).

The inductive power source device according to claim 15 or 16, wherein the feedback loop further comprises: at least one filter circuit (170), preferably an LC filter circuit, wherein the at least one filter circuit (170) is arranged to transform the first waveform signal (131) into a second waveform signal (171).

The inductive power source device according to any one of claims 15-17, wherein the feedback loop further comprises: - an adjustable voltage means (160), preferably a potentiometer, connected between the control means (130) and the switching amplifier (111), which controlled by the control means (130), and is arranged to output a third waveform signal (161) based on an input waveform signal, so that an amplitude of the third waveform signal (161) is below a predetermined level, the output of the controllable voltage means is arranged for supplying the input signal to the switching amplifier (111).