GB2564904A

GB2564904A - A multi-function light bulb

Info

Publication number: GB2564904A
Application number: GB1712106.2A
Authority: GB
Inventors: Conlon Gerry
Original assignee: Susevo Ltd
Current assignee: Susevo Ltd
Priority date: 2017-07-27
Filing date: 2017-07-27
Publication date: 2019-01-30
Anticipated expiration: 2037-07-27
Also published as: GB2564904B; GB201712106D0

Abstract

A multi-function lamp 1 comprises a light source 7 and a wireless power transmitter 8. The lamp is configured to operate in a first mode in which the light source outputs light and a second mode in which the wireless power transmitter transmits power wirelessly to be received by a wireless power receiver 38 positioned adjacent to the light bulb. The light source may be at least one light emitting diode (LED) and may comprise a plurality of light emitting diodes arranged in a circular configuration on a support portion of the light bulb. The support portion may be a substantially circular ring comprising an open central aperture. The lamp may further comprises a functional module having a wireless power receiver to receive power via an electromagnetic coupling with the wireless power transmitter. The functional module may be at least one of a sensor, a radio device, or an IoT (Internet of Things) node. The wireless power transfer may use inductive or resonant coupling.

Description

A multi-function light bulb

Technical field

The present invention relates to a multi-function light bulb. The present invention more particularly relates to a multi-function light bulb which incorporates a wireless power transmitter.

Background

With the proliferation of smartphones and portable media devices, there is an increase in demand for users to charge devices easily. The traditional method for charging a device involves connecting the device to a charger using a cable. However, the use of wireless charging is becoming more commonplace. Wireless charging allows a user to charge a device by the user placing the device on or adjacent to a wireless charging transmitter, without the user having to connect a cable to the device.

While wireless charging technology makes it easier for users to charge their devices, the proliferation of wireless chargers is still relatively low, with many users continuing to charge their devices by cable using chargers already in their possession. The cost and effort required to replace a conventional wired charger with a wireless charger provides a barrier to many users replacing their conventional wired chargers with wireless chargers.

There is a need for technology which can enable the proliferation of wireless chargers so that more users can benefit from the advantages of wireless charging. There is also a need to increase the number of chargers which are readily available for use so that users can charge their devices more frequently. This will enable device manufacturers to manufacture devices with smaller batteries to reduce the environment impact and cost of manufacturing devices.

The present invention seeks to provide an improved multi-function light bulb.

Summary of invention

According to the present invention, there is provided a multi-function light bulb comprising: a light source; and a wireless power transmitter, wherein the light bulb is configured to operate in a first mode in which the light source outputs light and a second mode in which the wireless power transmitter transmits power wirelessly such that power transmitted wirelessly by the wireless power transmitter can be received by a wireless power receiver positioned adjacent to the light bulb.

Preferably, the light bulb is configured to operate in a third mode in which the light source outputs light and, simultaneously, the wireless power transmitter transmits power wirelessly to a wireless power receiver.

Conveniently, the light bulb further comprises: a light bulb connector selected from a group including Edison screw, bayonet, G-type, T-type, bi-post or bipin.

Advantageously, the light source comprises at least one light emitting diode.

Preferably, the light source comprises a plurality of light emitting diodes which are arranged in a substantially circular configuration on a support portion of the light bulb.

Conveniently, the support portion is a substantially circular ring comprising an open central aperture.

Advantageously, the light bulb further comprises: a light source driver coupled electrically to the light source and configured to drive the light source to output light.

Preferably, the light source driver is a mains powered AC-DC driver circuit for driving a light emitting diode.

Conveniently, the AC-DC driver circuit is an AC-DC converter selected from a group including isolated flyback, non-isolated flyback, buck or buck-boost.

Preferably, the light source driver is a DC-DC driver circuit for driving a light emitting diode, the DC-DC driver circuit being configured to receive power from a DC power source.

Advantageously, the light bulb further comprises: an electrical transformer having a primary side winding which is coupled electrically to the light source driver and a secondary side winding which coupled electrically to the light source, wherein the transformer comprises a primary side auxiliary winding and a secondary side auxiliary winding, the primary side auxiliary winding being coupled electrically to the light source driver and the secondary side auxiliary winding being coupled electrically to the wireless power transmitter so that the secondary side auxiliary winding can supply power to the wireless power transmitter.

In some embodiments, the light source driver comprises a digital primary side controller which is coupled electrically to the primary side auxiliary winding to receive a feedback voltage from the primary side auxiliary winding to control the operation of the digital primary side controller.

In other embodiments, the light source driver comprises an analog primary side controller which is coupled electrically to the primary side auxiliary winding to receive a feedback voltage from the primary side auxiliary winding to control the operation of the analog primary side controller.

Preferably, the light bulb further comprises: a radio module which is coupled to the light source driver and is configured to communicate data wirelessly, wherein the light source driver is configured to operate in a first mode in which the digital or analog primary side controller provides a power management function and in a second mode in which the power management function is provided by the radio module such that the radio module can remain operational with minimal power consumption when the light bulb is in a standby mode.

Conveniently, the light bulb further comprises: a DC-DC converter circuit which is coupled electrically between the secondary side auxiliary winding and the wireless power transmitter to transfer power from the secondary side auxiliary winding to the wireless power transmitter.

Advantageously, the wireless power transmitter comprises a transmitter coil which is coupled electrically to a wireless power transmitter driver circuit, the wireless power transmitter driver circuit being configured to output a modulated signal to the transmitter coil to excite the transmitter coil so that the transmitter coil radiates an electromagnetic field to transmit power wirelessly to the wireless power receiver.

Preferably, the wireless power transmitter driver circuit comprises a charge control circuit which is coupled electrically to a coil driver circuit, the coil driver circuit being configured to output the modulated signal to the transmitter coil.

Conveniently, the coil driver circuit is a full-bridge driver circuit or a half-bridge driver circuit.

Advantageously, the wireless power transmitter comprises a device detector which is configured to detect the presence of a device when the device is positioned within a predetermined distance from the light bulb.

Preferably, the device detector comprises a detector selected from a group including an optical sensor or an ultrasonic sensor.

Conveniently, the light bulb further comprises: a support surface which is configured to carry a device to be charged by power transmitted wirelessly from the wireless power transmitter.

Advantageously, the wireless power transmitter is a wireless power transmitter which conforms to at least one of the standards in a group of wireless power transmission standards including an Alliance for Power standard or Wireless Power Consortium standard.

Preferably, the wireless power transmitter is a Qi certified or Qi-compliant transmitter.

Conveniently, the light bulb comprises a charge indicator arrangement which is configured to output an alert signal to a user to alert the user to a device being charged to a predetermined level.

Advantageously, the charge indicator arrangement comprises a timer circuit which, when activated, causes the light source to emit a pulsed light output.

Preferably, the light bulb further comprises: a functional module which comprises a wireless power receiver which is configured to receive power via an electromagnetic coupling with the wireless power transmitter.

Conveniently, the functional module is at least one of a sensor, a radio receiver, a radio transmitter, a radio transceiver or an loT node.

Advantageously, the functional module comprises an energy storage device which is configured to store energy received by the wireless power receiver.

Preferably, the energy storage device is at least one of a supercapacitor, a capacitor or a rechargeable battery.

Conveniently, the light bulb further comprises: a functional module support member which carries the functional module, wherein at least part of the energy storage device is positioned within the functional module support member.

Advantageously, the functional module support member is an elongate member, one end of the functional module support member carrying the functional module and the other end of the functional module support member carrying a first attachment arrangement, the first attachment arrangement being configured to releasably attach to a second attachment arrangement which is carried by a part of the light bulb so that the functional module support member can be releasably attached to the part of the light bulb.

Preferably, the first attachment arrangement is a screw fit connector and the second attachment arrangement is a screw fit socket.

Conveniently, the functional module is positioned so that a central portion of the functional module is aligned substantially with the centre of the circular configuration of light emitting diodes.

Advantageously, the light bulb further comprises: a housing which houses a least part of the wireless power transmitter.

Preferably, the functional module is configured to be releasably attached to the housing by a releasable attachment arrangement.

Brief description of drawings

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic perspective view of a light bulb of some embodiments,

Figure 2 is a diagrammatic cross-sectional view of a light bulb of some embodiments,

Figure 3 is a diagrammatic cross-sectional view of a light bulb of some embodiments,

Figure 4 is a diagrammatic perspective view of a light bulb of some embodiments,

Figure 5 is a circuit diagram of a light source driver of some embodiments,

Figure 6 is a circuit diagram of a light source driver of further embodiments,

Figure 7 is a block diagram showing components of a wireless charging system of some embodiments,

Figure 8 is a circuit diagram of a step-down buck converter of some embodiments,

Figure 9 is a circuit diagram of a timing arrangement of some embodiments,

Figure 10 is a diagrammatic perspective view of a light bulb of some embodiments which comprises a wireless charging arrangement that transmits power by resonance,

Figure 11 is a circuit diagram of a light source driver of some embodiments, and

Figure 12 is a circuit diagram of a control arrangement of some embodiments.

Detailed description

The inventor of the invention as described and claimed in the present application realised that the number of wireless chargers available to users could be increased by combining or integrating wireless charging technology with a light bulb. In particular, the inventor realised that a wireless charging transmitter could be integrated into a light bulb so that a user can charge a device wirelessly by placing the device on a support surface of the light bulb or in close proximity to the light bulb.

Integrating a wireless charging transmitter with a light bulb is counter-intuitive because one would not ordinarily place a delicate electronic device, such as a smartphone, on a light bulb for fear of damage to the device. However, the integration of the two technologies has significant benefits. For instance, it will lead to an increase in the proliferation of wireless charging points by enabling wireless charging technology to be provided in any location where a light bulb is in use. Integrating a wireless charging transmitter with a light bulb also provides an additional environmental benefit in that the light bulb performs two functions (i.e. as a light source and a wireless charger) instead of one, thereby reducing the total amount of materials required to provide both the lighting and charging functionality as compared with a separate light bulb and wireless charger.

The following description refers to inductive wireless charging technology. However, a light bulb of further embodiments comprises resonant wireless charging technology which is configured to charge a device wirelessly by a resonant coupling between a transmitter integrated in the light bulb and a receiver integrated in a device to be charged. It is within the skill and knowledge of a person skilled in the art how to implement the resonant wireless charging configuration in place of the inductive wireless charging configuration described below.

Referring now to figure 1 of the accompanying drawings, a multi-function light bulb 1 of some embodiments comprises a housing 2. In this embodiment, the housing 2 is an elongate housing with a narrow end 3 and an enlarged end 4.

A light bulb connector 5 is carried by the narrow end 3. The light bulb connector 5 is preferably a male electrical connector which is configured to connect the light bulb 1 to a corresponding light bulb connector, such as a female light bulb socket. The light bulb connector 5 is preferably a retrofit light bulb connector which is configured to connect to an existing light fitting. In this embodiment, the light bulb connector is an Edison screw fit connector, such as an E14, E27 or E26 connector. In other embodiments, the light bulb connector 5 is a light bulb connector selected from a group including bayonet, E14, GType, bi-post or bi-pin.

A support surface 6 is provided at the enlarged end 4 of the light bulb 1. In this embodiment, the support surface 6 is substantially planar and has a substantially circular shape. However, in other embodiments, the support surface 6 may be a different shape. The function of the support surface 6 is to support an electronic device which is placed on the support surface 6.

The light bulb of some embodiments may be a differently shaped light bulb with a support surface, such as a GU10, E27, E26, B22, E14 or a modified version of an A/GLS bulb that incorporates a support surface.

The light bulb 1 further comprises a light source which is preferably in the form of at least one light emitting diode (LED). In this embodiment, the light source comprises a plurality of LEDs 7. In this embodiment, the LEDs 7 are positioned adjacent to the support surface 6 and distributed at spaced positions across the support surface 6. In this embodiment, the LEDs 7 are grouped into an outer LED ring 7a and an inner LED ring 7b.

The light bulb 1 further comprises a wireless power transmitter which forms part of a wireless charging system (the receiver part of the wireless charging system being provided in a device to be charged). The wireless power transmitter comprises a wireless power transmitter loop or coil 8 which is carried by the housing 2. The wireless power transmitter coil 8 is, in this embodiment, carried by the support surface 6 and is positioned adjacent to the LEDs 7. The wireless power transmitter coil 8 preferably comprises a thin or ultra-thin ferrite/magnetic shield beneath it to improve inductive coupling with a wireless charging receiver without affecting the light paths of the LEDs 7.

The light bulb 1 further comprises a light source driver which is coupled electrically to the LEDs 7 and configured to drive the LEDs 7 to output light. The light source driver is described in detail below.

The wireless power transmitter coil 8 forms part of a wireless power transmitter which is integrated into the light bulb 1. The wireless power transmitter comprises a wireless power transmitter driver circuit which is coupled electrically to the wireless power transmitter coil 8. The wireless power transmitter driver circuit is described in detail below.

The light bulb 1 of some embodiments is configured to operate in a first mode in which the light source, which in this embodiment is the LEDs 7, outputs light. The light bulb 1 is further configured to operate in a second mode in which the wireless power transmitter transmits power wirelessly via the wireless power transmitter coil 8 to a wireless power receiver.

In some embodiments, the light bulb 1 is configured to operate in a third mode in which the light source outputs light and, simultaneously, the wireless power transmitter transmits power wirelessly to a wireless power receiver.

The light bulb 1 of some embodiments comprises a device detector which is configured to detect the presence of a device when the device is positioned on the support surface of the light bulb or within a predetermined distance from the light bulb 1. In the embodiment shown in figure 1, the light bulb 1 comprises a device detector which is configured to detect when a device is placed on the support surface 6. In this embodiment, when the device detector detects the presence of a device on the support surface 6, the light bulb 1 operates in the second mode in which the wireless power transmitter transmits power wirelessly via the wireless power transmitter coil 8 to a wireless power receiver within the device. The device receives power wirelessly and uses the power to charge an energy storage device, such as a rechargeable battery, a capacitor or a supercapacitor, within the device. A user can therefore place a device, such as a smartphone or other device to be charged, on the support surface 6 so that the device is charged wirelessly by power transmitted via the wireless power transmitter coil 8.

The optional device detector is, in some embodiments, a foreign object detector which comprises an optical detector in the form of an LED/photodiode arrangement. In other embodiments, the object detector comprises an ultrasonic sensor which is configured to sense the presence of an object placed on the support surface 6.

When the device detector does not detect the presence of a device on the support surface 6, the light bulb 1 is configured to operate in the first mode in which the light bulb 1 can output light from the LEDs 7. The light bulb 1 is therefore a multi-function light bulb which can operate in the same way as a conventional light bulb to output light as well as providing the functionality of a wireless charger.

The device detector of some embodiments comprises additional Internet of Things (loT) related functionality. For instance, the device detector of some embodiments is configured to transmit and/or receive information from a network of connected devices.

In some embodiments, the device detector detects the presence of a device on the support surface 6 inductively using the wireless power transmitter coil 8.

It is to be appreciated that the shape of the light bulb 1 shown in figure 1 is a shape according to one embodiment. The light bulb of other embodiments may have a different shape to the shape shown in figure 1 but with the same functionality as the light bulb shown in figure 1.

Referring now to figure 2 of the accompanying drawings, a light bulb 9 of some embodiments comprises many of the same components as the light bulb shown in figure 1 and the same reference numbers will be used for corresponding components. In this embodiment, the LEDs 7 are arranged in a substantially circular configuration on a support portion 10 of the light bulb 9.

The support portion 10 has an upper part 11 which defines a substantially circular ring comprising an open central aperture 12. The LEDs 7 are provided around an outer surface of the upper part 11 of the support portion 10.

In this embodiment, the light bulb 9 comprises a refractive optic element 13 which at least partly covers the LEDs 7 to refract light output by the LEDs 7 in the directions generally indicated by arrows 14.

The wireless power transmitter coil 8 is provided on an upper surface 15 of the support portion 10. In this embodiment, a ferrite or magnetic backing or shield layer 16 is provided between the upper portion 15 of the support portion 10 and the wireless power transmitter coil 8.

The light bulb 9 of this embodiment functions in the same way as the light bulb 1 of the embodiment described above. A device 17 is placed on a support surface 18 which, in this embodiment, is a surface adjacent to an upper side of the wireless power transmitter coil 8. A wireless power receiver coil 19 within the device 17 is positioned adjacent to the wireless power transmitter coil 8. When the light bulb 1 operates in the second mode, power is transmitted inductively from the wireless power transmitter coil 8 to the wireless power receiver coil 19. Power is therefore transmitted from the light bulb 9 to the device 17 to charge a battery within the device 17.

The wireless charging functionality of a light bulb of some embodiments is configured to charge a device with power in a range from below 1W up to 1520W. This power range can be accommodated within standard retrofit light bulb form factors as well as other light bulbs.

The wireless charging functionality of a light bulb of some embodiments is configured to charge a device selected from a group including, but not limited to, smartphones, tablets, wireless speakers, portable media players, wireless (loT) sensors or sensor nodes (a sensor node includes sensing and some form of wireless data communication to a separate device), headsets including wireless headsets, remote control units, wearables, keyboards or mice, tablet PC’s, hearing aids or digital cameras.

In other embodiments, the wireless charging functionality is configured to charge a device with power up to several kW. For instance, some embodiments enable an automotive battery to be charged wirelessly from a ceiling mounted light fixture.

Referring now to figure 3 of the accompanying drawings, a light bulb 20 of some embodiments comprises many of the same components as the embodiments described above and the same reference numbers will be used for corresponding components.

The light bulb 20 of this embodiment is configured with the LEDs 7 provided in a substantially circular or ring arrangement and carried by an end surface of the support portion 10. In this embodiment, the wireless power transmitter coil 8 is carried by the support portion 10 at a remote position from the LEDs 7. The wireless power transmitter coil 8 is provided within a central part of the support portion 10. A central part of the wireless power transmitter coil 8 is substantially aligned with the centre of the circle or ring defined by the circular arrangement of the LEDs.

The light bulb 20 of this embodiment is configured for use with a functional module 21. However, it is to be appreciated that the functional module 21 may be used with a differently shaped light bulb. The functional module 21 comprises a wireless power receiver having a wireless power receiver coil 22.

The functional module 21 is configured to releasably attach to the support portion 10 so that the wireless power receiver coil 22 is positioned adjacent to the wireless power transmitter coil 8. Power can therefore be transmitted inductively from the wireless power transmitter coil 8 to the wireless power receiver coil 22 to power the functional module or to charge an energy storage device within the functional module 21. In some embodiments, the functional module 21 comprises an energy storage device in the form of a supercapacitor, a capacitor or a rechargeable battery.

In some embodiments, the functional module 21 is formed integrally with the support portion 10 or another part of a housing of the light bulb 20. In these embodiments, the functional module 21 is either fixed to or removable from the support portion 10 or another part of a housing of the light bulb 20.

The functional module is preferably a low power consumption module. The functional module 21 is, in some embodiments, at least one of a sensor, a radio receiver, a radio transmitter, a radio transceiver or an loT node. However, it is to be appreciated that the functional module 21 may be any other type of low power functional module.

In some embodiments, the functional module 21 is a wireless sensor node including, but not limited to temperature, pressure, smoke or gas detectors, humidity, cameras, passive infrared sensors (PIR). In other embodiments the functional module 21 comprises a small or low power radio transceiver such as those based on Bluetooth™, Wifi™, LoRa™, Sigfox™ or other technology used in loT networks, security, building management (e.g. heating control), HVAC, fire or smoke alarms or alarm networks.

A radio provided in a sensor node functional module can perform two functions; (1) to communicate information from the sensor node to a central hub located within a building (using short range radio transmission, such as Bluetooth™ Low Energy (BLE), Wifi™, zigbee™) or over a longer distance if performing some form of outdoor monitoring (of water quality, for example), or (2) to communicate data to/from the light bulb which is charging it. For example, NFC or BLE may be used in both the light bulb and sensor node radios to establish a secure connection to transfer data between them. The secure connection can be used to uniquely identify the light bulb and sensor node, giving an added security layer to a typical loT network or building management system.

The functional module 21 is preferably configured to attach releasably to the support portion 10 of the light bulb 20 by a releasable attachment arrangement. In some embodiments, the releasable attachment arrangement is one of a magnetic attachment arrangement or an interference fit attachment arrangement. In other embodiments, the functional module 21 is not releasably attached to the support portion 10 but is instead integrated into the support portion 10.

The light bulb 20 of some embodiments comprises a communication arrangement which is configured to allow two-way contactless communication between the light bulb 20 and the functional module 21. In some embodiments, the two-way contactless communication is an optical communication arrangement involving LED and photodiode pairs.

The wireless power transmitter in the light bulb 20 provides power wirelessly to the functional module 21 without a user having to establish a direct wired connection between the functional module 21 and the light bulb 20. The light bulb 20 can therefore be encapsulated in an insulating material which protects the light bulb 20 and shields users from the electrical components within the light bulb 20.

The light bulb 20 is configured to allow the functional module 21 to be swapped easily with a further functional module, for instance to provide different functionality or to replace the functional module 21 in the event of a malfunction.

In some embodiments, the functional module 21 and the light bulb 20 are configured for two-way contactless communication between the light bulb 20 and the functional module 21 via the inductive coupling between the wireless power transmitter coil 8 and the wireless power receiver coil 22.

Referring now to figure 4 of the accompanying drawings, a light bulb 23 of some embodiments comprises many of the same components as the embodiments described above and the same reference numbers will be used for corresponding components. However, the light bulb 23 of this embodiment is larger than the light bulbs of the embodiments described above and may be configured for use in an industrial or commercial setting.

The light bulb 23 of this embodiment comprises a ring of LEDs 7 which are positioned around an end part 11 of the support portion 10. The light bulb 23 is configured for use with a functional module 21 which is carried by a functional module support member 24. The functional module support member 24 is an elongate member which carries the functional module 21 at one end and a first releasable attachment arrangement 25 at the other end.

The first releasable attachment arrangement 25 is configured to attach releasably to a second releasable attachment arrangement 26 provided on the support portion 10 of the light bulb 23. In this embodiment, the first and second releasable attachment arrangement are a screw thread attachment arrangement which permits the functional module support member 24 to be releasably attached to the support portion 10 of the light bulb 23. In other embodiments, a different releasable attachment arrangement may be used, such as a magnetic or interference fit attachment arrangement.

In some embodiments, an energy storage device of the functional module 21 is provided at least partly within the functional module support member 24. For instance, in some embodiments, the functional module support member 24 comprises at least part of a capacitor, a supercapacitor or a rechargeable battery. The size and length of the functional module support member may be selected according to the capacity of energy storage device which is needed to power the functional module 21. A longer or wider functional module support member 24 can therefore be used to house a larger energy storage device. Conversely, a thinner or shorter functional module support member 24 may be used to house a smaller energy storage device for use with the functional module 21.

In some embodiments, the releasable attachment arrangement 25, 26 is a simple mechanical connection. This simple mechanical connection is preferably for use with smaller fixture where connector space is at a premium. In this embodiment, data and power pass wirelessly from the wireless power transmitter coil 8 in the bulb 23 to the functional module 21 wirelessly.

In other embodiments, the releasable attachment 25, 26 includes electrical connectors which provide an electrically conductive coupling that allows data and/or power to pass between the light bulb 23 and the functional module 21.

The functional module 21 is spaced apart from the ring of LEDs 7, which are the main heat generators in the light bulb 23. The functional module 21 is therefore thermally isolated from the LEDs 7. The heat generated by the LEDs 7 is typically radiated from the rear of the LEDs 7 in a direction away from the functional module 21 which is preferably positioned on the end of the functional module support member 24 below the LEDs 7. In some embodiments, a finned heatsink is provided on the upper side of the ring of LEDs 7.

The energy storage device within the functional module support member 24 can be used to provide power to the functional module 21 in the event of a power failure. In other embodiments, energy from the energy storage device can be passed back to the support portion 10 of the light bulb 23 to provide power to the LEDs 7 to keep the LEDs 7 operational. For instance, energy from the energy storage device within the functional module support member 24 can be used to power the LEDs to perform emergency lighting functions.

Referring now to figure 5 of the accompanying drawings, an AC-DC driver circuit 27 of some embodiments is provided to drive the LEDs 7. The AC-DC driver circuit 27 is at least partly housed within part of the light bulb of some embodiments. In this embodiment, the AC-DC driver circuit 27 is an isolated flyback converter circuit. However, the light source driver of other embodiments may be a different type of mains powered AC-DC driver circuit. In some embodiments, the AC-DC driver circuit is an AC-DC converter selected from a group including isolated flyback, non-isolated flyback, buck or buck-boost.

The light source driver circuit 27 is configured to receive power from a power source which, in this embodiment, is a mains power source 28. In other embodiments, the light source driver circuit 27 is configured to receive power from a different power source, such as a DC power source.

The operation of the light source driver circuit 27 will now be described in terms of how the circuit drives the LEDs 7. The additional functionality of the driver circuit 27 to provide an output voltage Vin (wireless charger) to a wireless power transmitter circuit of the light bulb of some embodiments will be described below.

1. When mains power is applied to the input bridge rectifier (BR-i), the capacitor Cic charges via R_H. When V|_C reaches a minimum threshold voltage, the Control IC becomes operational and applies power to the gate of transistor Qi. The driver circuit 27 then starts to operate as a flyback converter (isolated or non-isolated), supplying current to the LEDs 7 on the secondary side so that the LEDs 7 output light.

2. In this embodiment, the Control IC is a digital primary-side controller, such as a iW6401 or iW36xx series controller from Dialog Semiconductor™. The LED voltage, V_Led, is controlled via voltage feedback from the primary-side auxiliary winding and can be set by the ratio of R_A and R_B or set digitally by the configuration of the Control IC. This Ra/Rb ratio also affects the output voltage named V|_N (wireless charger), which will become the input voltage to the wireless charging transmitter.

3. The LED current Led is at least partly set by the primary-side current sense resistor R_s which determines a feedback current I_Fb that is sensed by the Control IC such that increasing the value of R_s has the effect of reducing the LED current Led-

In other embodiments a different primary-side control IC can be used, such as a MPS40xx series controller from Monolithic Power™, an AL16xx series controller from Diodes Inc.™, an Onsemi™ NCL3018x series controller, a Silergy™ SSL52xx series controller or BP Semiconductor’s™ BP3198 controller.

In further embodiments, the driver circuit operates with analog primary-side control with an analog primary side controller instead of a digital primary-side controller.

Referring now to figure 6 of the accompanying drawings, an AC-DC driver circuit 29 of some embodiments comprises many of the same components as the driver circuit 27 described above. However, the driver circuit 29 of this embodiment comprises a modified secondary side connection for the wireless charging circuitry. In this embodiment, the output voltage V|_N (wireless charger) is the voltage across the secondary winding of the transformer as opposed to the centre tapped voltage in the driver circuit shown in figure 5.

The wireless power transmitter components of the light bulb of some embodiments will now be described with reference to figure 7.

The light bulb of some embodiments comprises a wireless power transmitter circuit 30 which is configured to output a modulated signal to the wireless power transmitter coil 8. The wireless power transmitter circuit of this embodiment comprises three functional blocks T1-T3.

The wireless power transmitter circuit 30 comprises a power supply input 31 which receives an input voltage Vin (wireless charger) which is output from the driver circuit 27. In this embodiment, V|_N (wireless charger) is input to functional block Ti. However, in other embodiments, functional block T1 is omitted and the input voltage Vin (wireless charger) is input directly into functional block T₂.

In some embodiments, the wireless power transmitter circuit is a Qi certified or Qi-compliant transmitter

Referring now to figure 8 of the accompanying drawings, functional block T1 of some embodiments comprises a buck converter circuit 32 which receives V|_N(wireless charger) as an input voltage. The buck converter circuit 32 comprises a control unit or IC 33. In some embodiments, the control IC 33 is an MP9942 controller from Monolithic Power ™.

The buck converter circuit 32 is a DC-DC down converter which provides an output voltage V_o that is provided as an input to functional block T₂.

The buck converter circuit 32 conditions the voltage V|_N (wireless charger) and outputs a conditioned voltage V_o. If the level of the voltage V|_N (wireless charger) is higher than the desired output voltage V_o, the buck converter circuit 32 steps down the voltage to the desired output voltage V_o. The output voltage level V_o is set by the resistor divider network Ri, R₂ and R₃.

The voltage conditioning provided by the functional block Ti allows flexibility in the design of the LED driver circuit 27, in particular the voltage ratios of the windings of the transformer of the LED driver circuit 27.

In some embodiments, functional block Ti is omitted when the output voltage Vin (wireless charger) does not require conditioning for input into functional block T₂.

Functional block T₂ receives an input voltage, which is either V_o from functional block Ti or V|_N (wireless charger)· In some embodiments this voltage input to functional block T₂ is a fixed voltage, such as 12V. In other embodiments, the voltage input to functional block T₂ is a voltage range, such as 5-20V.

Functional block T₂ is connected electrically to functional block T₃ and is configured to control a driver circuit 34 within functional block T₃.

The driver circuit 34 comprises a controller which, in some embodiments, is an integrated circuit which functions as a wireless charging controller. In this embodiment the controller is a P9242 controller from IDT™. In other embodiments, the driver circuit 34 comprises a controller selected from a group including WCT1011 (NXP™), a BQ5xxxx series from Texas

Instruments™, TS80002+TS51231 (Semtech™) or BD57020from Rohm™.

In this embodiment, functional block T₃ comprises a half-bridge driver circuit 35. In other embodiments, functional block T₃ comprises a full-bridge driver circuit.

Functional block T₂ comprises a wireless charging control circuit which is configured to control the driver circuit 34 in functional block T₃. The wireless charging control circuit of functional block T₂ receives a DC input voltage from functional block Ti or, if functional block Ti is omitted directly from V|_N (wireless charger). The DC input voltage is a fixed voltage, such as 12V or a voltage range, such as 5-20V.

The wireless charging control circuit of functional block T₂ comprises a microprocessor which is configured to control the driver circuit 34 in response to a feedback signal received from the wireless charging transmitter coil 8. The wireless charging control circuit of functional block T₂ is configured to control parameters including voltage, current, frequency, volt conditions and foreign object detection in order to control the driver circuit 34 in functional block T₃ to provide a modulated signal to the wireless charging transmitter coil 8 to excite the wireless charging transmitter coil 8 to transmit power wirelessly to the wireless power receiver coil 19.

As described above, the wireless power receiver coil 19 is carried by a device to be charged by wireless power transmitted by the wireless power transmitter coil 8. The device typically comprises three functional receiver blocks Ri-R₃. The first functional receiver block Ri is configured to condition and stabilise a DC voltage which is derived from the power received wirelessly by the wireless power receiver coil 19. The second functional receiver block R₂ is a charge controller which is coupled to the first functional receiver block Ri and configured to receive the conditioned DC voltage. The third functional receiver block R₃ is an energy storage device which is coupled to the charge controller of the second functional receiver block R₂ and is configured to be charged by a voltage output from the second functional receiver block R₂.

In some embodiments, the energy storage device of functional receiver block R₃ is a supercapacitor. In other embodiments, the energy storage device is a battery.

Functional blocks Ti and T₂ are configured to operate as follows:

1. When power is applied to the light bulb, the output voltages, V_Led and Vin(wireless charger), start to increase as power is transferred to the secondary side (figure 5).

2. As Vin (wireless charger) increases, the buck converter (figure 8) will power up and deliver power to T₂, allowing the wireless charger circuit to power up. As V_Led reaches a threshold voltage, the LEDs 7 will start to conduct and emit light.

3. The current in the secondary circuit I_Sec is limited by I_Fb (figure 5) and this secondary current I_Sec splits between supplying the LEDs 7 with current Led and the wireless charging circuitry with current l_wc. Lb is proportional to I_Sec = Led + lwc

4. If a device is placed on the support surface of the light bulb for charging and the device is significantly discharged to start with, the amount of current drawn by T₂/T₃, and hence Ti, will be high and the current available to supply the LEDs 7 will be less.

5. As the device charges, the wireless charging current decreases, with a subsequent increase in the current available to the LEDs 7. Thus, as the device charges the light output from the bulb increases accordingly, acting as a visual indicator to the user.

6. Eventually, the device will be fully charged and the Ti+T₂ combination will stop drawing current from the secondary windings.

7. At this point, the light bulb operates as a standard light bulb, with close to 100% of the secondary current going into the LEDs 7.

Referring now to figure 9 of the accompanying drawings, a light bulb of some embodiments comprises a charge indicator arrangement which is configured to indicate to a user when a device is fully charged by flashing or pulsing the LEDs 7. The charge indicator arrangement of some embodiments is provided within functional block T₂ and couples to functional block Ti which comprises a timer circuit 36 and the buck converter, as shown in figure 9.

In this embodiment, the timer circuit 36 comprises a TLC555-based timer. However, a different timer is used in other embodiments.

The wireless charging circuit of functional block T₂ of some embodiments comprises an output which indicates when a device that is being charged by wireless power transmission is fully charged. For example, in some embodiments, the wireless charging circuit comprises a controller, such as a P9242-R controller from IDT™ which comprises an indicator output which is configured to drive an indicator, such as an LED. The light bulb of some embodiments detects a signal from the indicator output (within T₂) and uses the signal to control the timer circuit 36. When the timer circuit 36 receives this indicator signal, ENcc, it indicates that charging is complete.

When the indicator output ENcc is ON, the indicator output ENcc causes the timer circuit 36 to turn transistor Qi on, with duty cycle 0.5sec ON, 9.5sec OFF. This enables current to flow in R₅, increasing l_wc and diverting current from LEDs 7 and causing light bulb to flash off for 0.5 seconds. The LEDs 7 of the light bulb return ON for 9.5 seconds, with this 10 second pattern repeating until the charged device is removed from the support surface of the light bulb. When the device is removed from the light bulb, the indicator output ENcc changes to OFF, such that Ti +T₂ no longer load the secondary circuit.

In other embodiments, the duty cycle has different ON and OFF timings to the embodiment described above to switch the LEDs 7 on and off for different lengths of time to the embodiment described above.

In some embodiments, to ensure good overall efficiency of the entire system, the functional blocks Ti, T₂ and T₃ consume minimal power when the wireless charging function is not required. So, for practical implementation, the integrated circuits and the circuit design is implemented to ensure ultra-low power consumption is achieved when the wireless charger circuitry is in standby or no-load states.

While the embodiments described above primarily use an inductive coupling to transmit power wirelessly to a device, a light bulb of other embodiments is configured to transmit power wirelessly by resonance. Referring now to Figure 10 of the accompanying drawings, a light bulb 37 of some embodiments comprises a wireless charging system based on resonance. In this embodiment, the light bulb 37 is configured to charge a device 38 wirelessly by resonance when magnetics within the device 38 are placed on or above or otherwise in close proximity to transmitting magnetics provided in the light bulb 37.

Referring now to figures 11 and 12 of the accompanying drawings, an AC-DC driver circuit 39 of some embodiments comprises many of the same components as the driver circuit 27 described above. However, the driver circuit 39 of this embodiment comprises a modified threshold management arrangement 40. The driver circuit 39 of this embodiment is coupled to a radio module 41 which enables the light bulb to communicate data wirelessly. In some embodiments, the radio module is a Bluetooth module, a Bluetooth™ Low Energy (BLE) module, a Wifi™ module, a zigbee™ module or another system on a chip (SoC) radio module. In other embodiments, the light bulb is provided with a sensor or other functional module in addition to or instead of the radio module 41. In these embodiments, the radio module 41 and/or the sensor or other functional module typically requires power when the lighting output is zero.

The threshold management arrangement 40 and the radio module 41 is shown in detail in figure 12 of the accompanying drawings. The driver circuit 39 which incorporates this threshold management arrangement 40 operates as follows:

i. Power on: V|_C comes up before Vradio, so that Control IC & loop stabilises quickly (transistor TMS remains open).

1. Vradio start-up is controlled by the R-iCradio time constant, R₂gives further control of radio module 41 start time (figure 12).

ii. The circuit combining D₃, R₃, Clarge (e.g. supercapacitor) and D₄enables the radio module 41 to stay alive, without taking power from mains input. This enables ultra-low standby power to be achieved.

1. If the radio commands “light off”, in terms of power management the radio module 41 becomes the “command IC” with the primaryside Control IC becoming a slave to keep the radio module 41 powered up. The master power management control function is thus transferred away from the Control IC to the radio module 41.

iii. The primary benefit of the circuitry is that it eliminates the need to take power from the high voltage feed to the primary winding. Instead, the radio module 41 feeds off a low voltage winding, V_Aux, when the lighting is ON, with the supercapacitor Clarge charging to power the radio module 41 when the light is OFF.

iv. Threshold Management Element:

1. Linear regulators (LDOs) are used on the input to the radio module 41 and can be used on the output from Vsecondary sensing, so that the radio module 41 and secondary sensors have “spare voltage overhead”, which would allow a “Control IC burst mode”, without turning on the output LEDs, as the transformer winding ratios are set to just deliver the required LED voltage when V|_C is at nominal voltage.

2. If mains power is applied to the bulb, with Radio command set to Light OFF, then eventually the supercapacitor Clarge will start to charge. In this state, the radio module 41 will control TMS, such that V_Fb is increased to the Control IC, allowing sufficient voltage to be generated to charge Cradio, Clarge (supercapacitor), any circuitry powered by Vsecondarysensing, but insufficient voltage head to enable output LEDs to turn ON.

3. The overall circuit will operate in a form of burst mode, with the duty cycle controlled by the charging.

v. The combination of circuits keeps the radio module 41 alive, even if socket power is temporarily removed.

vi. The circuit allows for a secondary tap winding to power sensors and alarms. This could include a supercapacitor on the secondary, with the advantage one would have an independently powered sense/alarm circuit with electrical isolation from the mains voltage (if an isolated transformer was employed).

In the present specification comprise means includes or consists of and comprising means including or consisting of'.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a

29

means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A multi-function light bulb comprising:

a light source; and a wireless power transmitter, wherein the light bulb is configured to operate in a first mode in which the light source outputs light and a second mode in which the wireless power transmitter transmits power wirelessly such that power transmitted wirelessly by the wireless power transmitter can be received by a wireless power receiver positioned adjacent to the light bulb.

2. The light bulb of claim 1, wherein the light bulb is configured to operate in a third mode in which the light source outputs light and, simultaneously, the wireless power transmitter transmits power wirelessly to a wireless power receiver.

3. The light bulb of claim 1 or claim 2, wherein the light bulb further comprises:

a light bulb connector selected from a group including Edison screw, bayonet, G-type, T-type, bi-post or bi-pin.

4. The light bulb of any one of the preceding claims, wherein the light source comprises at least one light emitting diode.

5. The light bulb of any one of the preceding claims, wherein the light source comprises a plurality of light emitting diodes which are arranged in a substantially circular configuration on a support portion of the light bulb.

6. The light bulb of claim 5, wherein the support portion is a substantially circular ring comprising an open central aperture.

7. The light bulb of any one of the preceding claims, wherein the light bulb further comprises:

a light source driver coupled electrically to the light source and configured to drive the light source to output light.

8. The light bulb of claim 7, wherein the light source driver is a mains powered AC-DC driver circuit for driving a light emitting diode.

9. The light bulb of claim 8, wherein the AC-DC driver circuit is an AC-DC converter selected from a group including isolated flyback, non-isolated flyback, buck or buck-boost.

10. The light bulb of claim 7, wherein the light source driver is a DC-DC driver circuit for driving a light emitting diode, the DC-DC driver circuit being configured to receive power from a DC power source.

11. The light bulb of any one of claims 7 to 10, wherein the light bulb further comprises:

an electrical transformer having a primary side winding which is coupled electrically to the light source driver and a secondary side winding which coupled electrically to the light source, wherein the transformer comprises a primary side auxiliary winding and a secondary side auxiliary winding, the primary side auxiliary winding being coupled electrically to the light source driver and the secondary side auxiliary winding being coupled electrically to the wireless power transmitter so that the secondary side auxiliary winding can supply power to the wireless power transmitter.

12. The light bulb of claim 11, wherein the light source driver comprises a digital primary side controller which is coupled electrically to the primary side auxiliary winding to receive a feedback voltage from the primary side auxiliary winding to control the operation of the digital primary side controller.

13. The light bulb of claim 11, wherein the light source driver comprises an analog primary side controller which is coupled electrically to the primary side auxiliary winding to receive a feedback voltage from the primary side auxiliary winding to control the operation of the analog primary side controller.

14. The light bulb of claim 12 or claim 13, wherein the light bulb further comprises:

a radio module which is coupled to the light source driver and is configured to communicate data wirelessly, wherein the light source driver is configured to operate in a first mode in which the digital or analog primary side controller provides a power management function and in a second mode in which the power management function is provided by the radio module such that the radio module can remain operational with minimal power consumption when the light bulb is in a standby mode.

15. The light bulb of any one of claims 11 to 14, wherein the light bulb further comprises:

a DC-DC converter circuit which is coupled electrically between the secondary side auxiliary winding and the wireless power transmitter to transfer power from the secondary side auxiliary winding to the wireless power transmitter.

16. The light bulb of any one of the preceding claims, wherein the wireless power transmitter comprises a transmitter coil which is coupled electrically to a wireless power transmitter driver circuit, the wireless power transmitter driver circuit being configured to output a modulated signal to the transmitter coil to excite the transmitter coil so that the transmitter coil radiates an electromagnetic field to transmit power wirelessly to the wireless power receiver.

17. The light bulb of claim 16, wherein the wireless power transmitter driver circuit comprises a charge control circuit which is coupled electrically to a coil driver circuit, the coil driver circuit being configured to output the modulated signal to the transmitter coil.

18. The light bulb of claim 17, wherein the coil driver circuit is a full-bridge driver circuit or a half-bridge driver circuit.

19. The light bulb of any one of the preceding claims, wherein the wireless power transmitter comprises a device detector which is configured to detect the presence of a device when the device is positioned within a predetermined distance from the light bulb.

20. The light bulb of claim 19, wherein the device detector comprises a detector selected from a group including an optical sensor or an ultrasonic sensor.

21. The light bulb of any one of the preceding claims, wherein the light bulb further comprises:

a support surface which is configured to carry a device to be charged by power transmitted wirelessly from the wireless power transmitter.

22. The light bulb of any one of the preceding claims, wherein the wireless power transmitter is a wireless power transmitter which conforms to at least one of the standards in a group of wireless power transmission standards including an Alliance for Power standard or Wireless Power Consortium standard.

23. The light bulb of claim 22, wherein the wireless power transmitter is a Qi certified or Qi-compliant transmitter.

24. The light bulb of any one of the preceding claims, wherein the light bulb comprises a charge indicator arrangement which is configured to output an alert signal to a user to alert the user to a device being charged to a predetermined level.

25. The light bulb of claim 24, wherein the charge indicator arrangement comprises a timer circuit which, when activated, causes the light source to emit a pulsed light output.

26. The light bulb of any one of the preceding claims, wherein the light bulb further comprises:

a functional module which comprises a wireless power receiver which is configured to receive power via an electromagnetic coupling with the wireless power transmitter.

27. The light bulb of claim 26, wherein the functional module is at least one of a sensor, a radio receiver, a radio transmitter, a radio transceiver or an loT node.

28. The light bulb of claim 26 or claim 27, wherein the functional module comprises an energy storage device which is configured to store energy received by the wireless power receiver.

29. The light bulb of claim 28, wherein the energy storage device is at least one of a supercapacitor, a capacitor or a rechargeable battery.

30. The light bulb of claim 28 or claim 29, wherein the light bulb further comprises:

a functional module support member which carries the functional module, wherein at least part of the energy storage device is positioned within the functional module support member.

31. The light bulb of claim 30, wherein the functional module support member is an elongate member, one end of the functional module support member carrying the functional module and the other end of the functional module support member carrying a first attachment arrangement, the first attachment arrangement being configured to releasably attach to a second attachment arrangement which is carried by a part of the light bulb so that the functional module support member can be releasably attached to the part of the light bulb.

32. The light bulb of claim 31, wherein the first attachment arrangement is a screw fit connector and the second attachment arrangement is a screw fit socket.

33. The light bulb of any one of claims 26 to 32 as dependent on claim 5 or claim 6, wherein the functional module is positioned so that a central portion of the functional module is aligned substantially with the centre of the circular configuration of light emitting diodes.

34. The light bulb of any one of the preceding claims, wherein the light bulb further comprises:

a housing which houses a least part of the wireless power transmitter.

35. The light bulb of claim 34 as dependent on any one of claims 26 to 29, wherein the functional module is configured to be releasably attached to the housing by a releasable attachment arrangement.