Technical field

The present invention relates to a control device for a lighting system. More particularly, the present invention relates to a wireless dimmer and a lighting system comprising such wireless dimmer.

Background

Wireless control of lighting systems is subject to increased popularity. There are several known systems wherein the lighting device, i.e. the light source, is connected to the internet either directly, by means of internet connection provided in the light source, or indirectly by providing the power line with an internet-supported switch. For these systems control is normally achieved by activating a client application on a smartphone. Upon activation a wireless connection is established between the smartphone and a control device, which in accordance with the description above may be arranged within the electrical circuitry of the light source itself or as a separate switch in the power line. A user may thus control the driving power for the light source by appropriate tuning via the smartphone application in order to achieve desired dimming of the light source.

DE102013015284 describes an alternative system for dimming lights, wherein a cube having a magnetic sensor is configured to control dimming. When a user rotates the cube a signal representing the desired dimming based on the rotational movement is transmitted to the dimmer circuit, thus providing appropriate dimming of the light source.

The system taught by the above-mentioned prior art suffers from a significant drawback. As every rotation will cause a corresponding control signal for the associated light source unintentional dimming will occur each time a user moves the cube. In view of the above there is a need for an improved control device for lighting systems.

Summary

An object is therefore to provide a control device for a lighting system which solves the drawbacks of the prior art.

An idea is to provide a control device which communicates directly with a dimming circuit of an associated lighting device, wherein the control device has a control device state sensor for identifying a pre-programmed operating state, such as a fixed position. The control device further comprises a rotational sensor, and radio communication means configured to transmit a control signal representing a desired dimming level based on the detected rotational movement. Control of the dimming circuit is provided only if the pre-programmed operating state is detected by the control device state sensor. A control device configured according to the above-mentioned idea will greatly reduce, or even prevent, unintentional dimming.

In accordance with a first aspect, a control device for a lighting system is provided. The control device is dedicated for providing control signals for an associated dimmer circuit of the lighting system, and comprises a rotational sensor for detecting a rotational movement of the control device; a control device state sensor, such as a position sensor or motion sensor, for detecting a current state of the control device; radio communication means configured to transmit a control signal to a light source of said lighting system; and a controller. The controller is configured to i) determine the control signal, based on the detected rotational movement, only when the current state detected by the control device state sensor matches a pre-programmed operating state, or ii) determine the control signal, based on the detected rotational movement, and to control the radio communication means to transmit the control signal only when the current state detected by the control device state sensor matches a preprogrammed operating position.

The control device may comprise a housing, wherein said rotational sensor, said position sensor, said radio communication means, and said controller are enclosed within said housing. The electronics used for controlling the light source may thus be provided as a single unit.

The housing may have a planar support surface. The housing may thus rest on a surface such that the current position is well defined and consequently well comparable with pre-determined or pre-programmed operating positions.

The housing may further comprise a body extending from said support surface, wherein the area of said support surface is smaller than a cross-section of the body being parallel with the support surface such that the housing exhibits a tapered shape. Gripping and handling of the control device is thus improved.

In an embodiment the housing, when the control device is arranged in one of the preprogrammed operating positions, has a width being larger, or even substantially larger, than the height of the control device. Gripping and handling is thus improved, since the housing may have a shape of a wheel, or disc, thus implying and facilitating rotation.

The control device may further comprise a magnet, said magnet being arranged adjacent to said support surface within said housing. The magnet allows attaching the control device to various supports or support surfaces, and also allows two or more control devices to be connected to each other.

The rotational sensor may be an accelerometer and/or a gyroscope, and the control device state sensor may be a tilt sensor. In a preferred embodiment, the rotational sensor is a gyroscope, while the tilt sensor is an accelerometer. The pre-programmed operating state may correspond to a position in which the control device is resting on a horizontal surface, and/or a position in which the control device is resting against a vertical surface. This reduces the risk of unintentional dimming.

The controller may be configured to determine the control signal by comparing the current state detected by the control device state sensor with a predetermined threshold value, and if the current state is below the threshold value, determining that the current state matches the pre-programmed operating state.

The current state detected by the control device state sensor may be a representation of a current acceleration vector.

The pre-programmed operating state may be a representation of a pre-set acceleration vector.

The controller may be provided with a manual input channel for allowing user control of the control device. This allows the user to pair the control device with further light sources. The manual input channel of the controller may be provided as a push-button.

According to a second aspect a lighting system is provided. The lighting system comprises a light source having a dimmer circuit connected thereto, said dimmer circuit being configured to receive control signals via radio communication, wherein said lighting system further comprises at least one control device according to the first aspect.

According to a third aspect, a method for controlling a dimmer circuit of an associated light source by means of a remote control device is provided. The method comprising the steps of detecting a rotational movement of the control device by means of a rotational sensor;

detecting a current state of the control device by means of a control device state sensor; and i) determining the control signal only when the current state detected by the control device state sensor matches a pre-programmed operating state, or ii) determining the control signal and controlling radio communication means of said control device to transmit the control signal only when the current state detected by the control device state sensor matches a pre-programmed operating state.

According to a fourth aspect, a lighting system is provided. The lighting system comprises a light source having a dimmer circuit connected thereto, said dimmer circuit being configured to receive control signals via radio communication. The lighting system further comprises at least one control device, said control device comprising a rotational sensor for detecting a rotational movement of the control device; a control device state sensor for detecting a current state of the control device; radio communication means configured to transmit a control signal to a light source of said lighting system; and a controller configured to determine the control signal. The control signal comprises information representing the desired dimmer action based on the rotational movement, and if the current state of the control device matches a pre-programmed operating state. The dimmer circuit is configured to perform dimming only when the control signal comprises information that the current state detected by the control device state sensor matches a pre-programmed operating state.

According to a fifth aspect, a dimmer circuit for use with a lighting system according to the fourth aspect is provided.

Brief Description of the Drawings

In the following description reference will be made to the appended drawings, in which:

Fig. la is a schematic view of a lighting system according to an embodiment;

Fig. lb is a schematic view of lighting systems according to various embodiments;

Fig. 2a is a schematic view of the components included in a control device according to an embodiment;

Fig. 2b is a schematic view of the control device shown in Fig. 2a;

Fig. 2c is an isometric view of the control device shown in Fig. 2a;

Figs. 3a-c are schematic views of a lighting system during operation;

Fig. 4 is an isometric view of a plurality of control devices being stacked in accordance with an embodiment; and

Fig. 5 is an isometric view of a lighting system using a control device according to an embodiment.

Detailed Description

The embodiments described in the following relate to a lighting system, and in particular to a control device for use with such lighting system. Starting in Fig. la, a lighting system 10 is shown. The lighting system 10 comprises a light source 12, here illustrated as a floor standing lamp, and a control device 100 for controlling the light source 12.

As can be seen in Fig. la the lamp 12 is connected to mains power by means of a power plug 14. Power is supplied from the mains to a lighting element 16, optionally via a power switch 18. The light source 12 further comprises a dimmer circuit 20. The dimmer circuit 20, being only schematically shown, is arranged in the power path somewhere between the power supply (mains) and the lighting element 16; preferred positions include at the power plug 14, at the switch 18, at the lighting element 16, or at a socket 19 used for connecting the lighting element 16. However, other positions of the dimmer circuit 20 are also possible as long as it is capable of dimming the light source 12. For example, the light source 12 may be a roof-hung lamp wherein the dimmer circuit 20 could be arranged at the on/off switch, normally arranged at a wall remotely of the lamp itself. The light source 12 could also be a battery-powered light source, wherein the dimmer circuit 20 could be arranged in connection with some of the electronics used to drive the light source 12. As will be evident from the following, the lighting system 10 could in principle utilize any kind of light source 12 as long as it allows for connecting a dimmer circuit 20 to it.

The light source 12 has been described as being a lamp. However the light source 12 could just as well be a bulb with a dimmer circuit 20 integrated in the bulb.

As can be further seen in Fig. la the control device 100 communicates directly with the dimmer circuit 20 of the light source 12. Hence, the control device 100 as well as the dimmer circuit 20 is provided with suitable radio communication means as will be further described below. Direct communication between the control device 100 and the dimmer circuit 20 is however not required; the control device 100 may also communicate with the dimmer circuit 20 e.g. via the internet.

In a preferred embodiment the control device 100 communicates with the dimmer circuit 20 using the ZigBee radio protocol. This particular radio standard will not be described further, however it has proven to be highly advantageous for this particular lighting system 10, e.g. due to its low power consumption and mesh network layout.

When the control device 100 is activated, a control signal is generated and transmitted wireless to the dimmer circuit 20 of the associated light source 12. Upon receiving the control signal, the dimmer circuit 20 is controlled accordingly by reducing or increasing the power supplied to the lighting element 16. Hence, the control device 100 is a remote dimmer control for the light source 12.

In Fig. lb different lighting systems are shown. Four control devices lOOa-d are provided for controlling the dimmer circuits of three light sources 12a, 12b, 12c. The first control device 100a is programmed to be associated with the first light source 12a. As can be seen in Fig. lb, the control device 100a may communicate with the associated light source 12a in different ways. A first communication link may be established directly between the control device 100a and the light source 12a. However, should there be no direct communication available, for example if the control device 100a is moved to a remote location from the light source 1 12a such that the distance exceeds the range of the radio transmitter of the control device 100a, a second communication link may be established. In this second communication link, also illustrated in Fig. lb, the control signal transmitted by the control device 100a is received by the third control device 100c, being within range of the first control device 100a.

Once received, the third control device 100c will pass on, or forward, the control signal which is then received by the second control device 100b. The second control device 100b is thus within range of the third control device 100c. As the second control device 100b is also within range of the light source 12a, the control signal is transmitted from the second control device 100b to the light source 12a. The second control device 100b is associated with the second light source 12b. As the light source 12b is within range of the second control device 100b, a direct communication link is provided between the control device 100b and the light source 12b.

The third control device 100c is associated with the third light source 12c. As the light source 12c is within range of the second control device 100c, a direct communication link is provided between the control device 100c and the light source 12c.

A fourth control device lOOd is also associated with the third light source 12c. Hence, a single light source 12 may be associated with one or more control devices 100, as well as one control device 100 may be associated with one or more light sources 12. The fourth control device lOOd is shown to communicate with its associated light source 12c either directly, or via a router 30 provided to transmit communication signals, i.e. control signals, between the different network components i.e. control devices 100 and dimmer circuits 20.

All of the above-mentioned communication links are available by means of the ZigBee protocol. Other radio communication protocols, providing one or more of the above- mentioned communication links, may also be used for the embodiments described herein.

In Fig. 2a the control device 100 is shown in further detail, although schematically only. The control device 100 has a housing 1 10 enclosing various electronic components. A power supply 120, such as a Lithium-Ion battery or the like, is provided and being electrically connected to a controller 108. The controller 108, being configured to determine a control signal based on various data input, is configured to control a radio communication unit 106 for transmitting said control signal to an associated light source 12. The radio communication unit 106, forming radio communication means, is also powered by the power supply 120.

While the controller 108 transmits its output, i.e. the control signal, to the radio communication unit 106 it receives input from at least two sensors 102, 104. A first sensor 102 is a rotational sensor 102, receiving power from the power supply 120. The rotational sensor 102 is configured to measure, and thus to detect, a rotational movement of the control device 100. Preferably, the rotational sensor 102 is configured to detect and measure the rotational movement around an axis being parallel with a normal of the control device 100. As the control device 100 has at least one planar support surface 1 12 as is shown in Figs. 2b and 2c, the normal direction is perpendicular to the plane of the planar support surface 1 12. The rotational sensor 102 transmits its output, i.e. the measured rotational movement, to the controller 108. In a preferred embodiment, the rotational sensor 102 is realized by means of a gyroscope.

The second sensor 104 is a control device state sensor, e.g. a tilt sensor in the form of an accelerometer, also being powered by the power supply 120. The control device state sensor 104 is configured to detect and measure a current state of the control device 100, preferably a tilt angle of the planar support surface 1 12 relative a horizontal or vertical plane or an acceleration vector representing the current motion of the control device 100. As for the rotational sensor 102, the position sensor 104 transmits its output signal, e.g. the measured tilt angle or acceleration vector, to the controller 108.

Except for the digital inputs, the controller 106 preferably also has a further input channel in the form of a push button 130 or the like. The button 130 is preferably hidden during normal operation. This may be achieved by arranging the push button 130 on the underside of the control device 100, and made accessible only by inserting a sharp object through a small hole provided in the housing 110. The button 130 may control various functions of the control device 100, such as pairing with light sources 12 or resetting the control device 100. In one example, depressing of the button 130 while also within a predetermined time pressing a similar button on an associated dimmer circuit 20 will pair the control device 100 to that particular light source 12. Further pairing may be allowed, such that a subsequent pairing operation with another dimmer circuit 20 will add the new dimmer circuit 20 to the one already being paired. A LED indicator (not shown) may also be provided for indicating when pairing is successful. In such manner the control device 100 may be paired with a plurality of dimmer circuits 20.

Resetting may e.g. be achieved by depressing the button 130 for a certain time, such as e.g. 10 seconds or more. Upon resetting, the control device 100 may delete any added pairing(s), such that the control device 100 returns to a pre-set state. Preferably, the pre-set state corresponds to the state of the control device 100 prior to any user-initiated additional pairings.

In addition to the components mentioned above the housing 110 further encloses a magnet 140 used to attach the control device 100 to dedicated supports, or to other control devices 100. This will be further explained with reference to Figs. 4 and 5.

Turning to Figs. 2b and 2c the housing 110 is shown having a disc-like shape, wherein a lower surface forms a planar support surface 112. The housing 110 can thus be said to comprise a body 114 extending upwards from the support surface 112. The area of the support surface 112 is preferably smaller than a cross-section of the body 114 being parallel with the support surface 112 such that the housing 110 exhibits a tapered shape. The tapered shape of the housing 110 is particularly advantageous by the fact that gripping and handling is facilitated, since the fingers of a user may easily grab the periphery of the control device 100 without actually touching the underlying table or support structure.

As can be seen in Figs. 2b and 2c, the magnet 140 is preferably arranged close to the lower support surface 112. A magnetic shield (not shown) may be provided between the magnet 140 and the electronic equipment 102, 104, 106, 108, 120 in order to reduce radio signal interference. Hence, the components of the control device 100 may be arranged in a layer structure, wherein the electronic components are stacked onto the magnet 140.

Now turning to Figs. 3a-c, operation of the control device 100 and the entire lighting system 10 will be described. Before the control device 100 can control the dimmer circuit 20 of the light source 12 pairing is required. This may be performed according to various pairing schemes; if the dimmer circuit (either integrated with the light source 12 or provided as a separate component) is provided separately from the control device 100 a user may pair the control device 100 with the associated dimmer circuit(s), e.g. using the button 130 described above. In other embodiments, the control device 100 is paired with an associated dimmer circuit 20 already during manufacturing, such that one control device 100 is dedicated to a specific dimmer circuit 20. Once pairing is completed the control device 100 is allowed to control dimming of the associated light source(s) 12. For proper functionality, the control device 100 should be located within a certain distance from the light source 12. The distance is normally set by the range of the radio communication means 106, although the range may be increased by a mesh network in accordance with the ZigBee protocol.

In Fig. 3a, a lighting system ready for operation is shown. This means that the control device 100 is paired to the dimmer circuit of the light source 12, and that the light source 12 receives power from an associated power source such that the light source 12 is on. As can be seen in Fig. 3a, despite the supplied power the light source 12 is emitting only a fraction of its maximum light. When dimming of the light source 12 is desired, in this case for increasing the emitted light, a user simply grabs the control device 100 and starts a rotating movement of the entire control device 100 in a direction corresponding to light increase. The rotational sensor 102 will thus sense the movement and immediately measure movement characteristics such as rotational speed (i.e. angular velocity), rotational direction, rotational acceleration or deceleration, start and stop position, etc. The control device state sensor 104 will also start to detect the current state of the control device, in a preferred embodiment the control device state sensor 104 is detecting the tilt angle relative a reference plane. The reference plane is preferably a horizontal plane or a vertical plane. Optionally the control device state sensor 104 detects a motion of the control device, in particular a non-rotational motion which may occur if a person is walking around holding the control device. The controller 108 may in such case be configured to determine the control signal by comparing the current state, i.e. the non-rotational motion with a predetermined threshold value. The current state may be represented by an acceleration vector, wherein the predetermined threshold value may represent a specific acceleration vector of the control device. Once the sensors 102, 104 have transmitted their respective data to the controller 108, the controller determines i) if the rotational movement is intentional, and ii) the control signal for the dimmer circuit 20.

The two steps performed by the controller 108 may in fact be made in sequence, such that the controller 108 firstly determines if the rotational movement is intentional by comparing the detected current state with a pre-programmed operating state. If the current state equals a pre-programmed operating state, or if the detected current state is within a pre-set interval compared to the pre-programmed operating state, the controller 108 continues by determining the control signal from the input provided by the rotational sensor 102. As can be seen in Figs. 3b and 3c, a rotation of the control device 100 will cause a corresponding light intensity increase from the light source 12.

The control signal may be determined in various ways. For example, only the start and stop position of the rotational movement is relevant for determining the control signal. In such embodiment, the rotational movement is preferably mapped relative dimmer voltage output such that a pre-set rotational movement corresponds to 100% dimmer action. In one specific embodiment, a rotational movement of 90° corresponds to a dimmer action from 0-100%, or from 100-0% in power output depending on the rotational direction. This means that if a user turns the control device 100 a quarter of a full turn, depending on the rotational direction the light source 12 will change from its current dimmer state to either maximum light intensity, or to minimum light intensity. Should the user instead choose to turn the control device 100 only a portion of a quarter of a turn, the resulting dimming action will be a corresponding percentage. As the described embodiment may in some cases result in a rotational movement not resulting in a dimming action (if the performed rotational movement is an angular distance being less than a movement corresponding to the current dimming setting), other embodiments may be considered.

In one embodiment, preventing the situation addressed above, the relationship between dimmer action and rotational movement is dynamic. Such embodiment may be realized by programming the controller 108 to map a specific rotational movement, such as 90° turn, corresponds to the dimming action from the current dimming setting to maximum or minimum light intensity. This means that if the current dimmer setting is at 40% power output, a 90° turn will result in a change from 40-100%, or from 40-0% depending on the rotational direction.

The above embodiments thus require only the start and stop positions of the rotational movement, or more properly the angular distance covered by the rotational movement.

In a yet further embodiment, additional rotational movement characteristics are determined and used for controlling the dimmer circuit of the light source 12. Such

characteristics may e.g. be rotational speed, or rotational acceleration or deceleration. Examples of such controls may include that the dimmer action corresponding to the angular distance is dependent of the rotational speed. Giving only a few examples, a pre-set angular distance, such as 90°, may represent a dimming action to 0% or 100% from the current dimmer setting only if the rotational speed is above a predetermined threshold. The threshold may be set to 907s, whereby the resulting dimmer action will be less if the rotational speed is below the threshold. Should the rotational speed be half of the threshold, i.e. 457s, the dimming action may result in a far less dimmer action even if the maximum angular distance is applied. This allows for fine tuning of the light intensity, as the user may choose to turn the control device 100 slowly in order to reduce the maximum allowable change in light intensity. The speed relationship may be divided in several steps, whereby a full movement using fast rotational speed may correspond to a change to max or min, a full movement using a medium rotational speed may correspond to a change towards max or min by a factor of e.g. 0,5, and a full movement using a slow rotational speed may correspond to a change towards max or min by a factor of e.g. 0,2.

In a yet further embodiment the relationship between rotational movement and corresponding dimmer action is progressive. This means that for a pre-defined full movement, such as 90°, the initial angular distance will correspond to a greater or lesser change of dimmer setting than the final angular distance. If e.g. the full movement is set to 90°, corresponding to a change to 0% or 100% light intensity depending on the rotational direction, the initial 45° rotational movement may correspond to a change of ± 10% while the final 45° correspond to the remaining 90% change. The opposite control is also applicable, such that the initial 45° rotational movement may correspond to a change of ± 90% while the final 45° correspond to the remaining 10% change.

The control device 100 may e.g. be programmed such that a clockwise rotation corresponds to light intensity increase, while a counter-clockwise rotation corresponds to light intensity decrease.

According to one embodiment, which may be combined with any one of the schemes for determining the control signal mentioned above, the relationship between the rotational pattern of the control device 100 and the corresponding dimmer action is split into two sub- schemes. A first scheme is applied if the rotational speed is above a pre-determined threshold value, while a second scheme is applied if the rotational speed is equal to, or below, the predetermined threshold value.

The first scheme may be programmed such that full dimming action is requested independently of the exact rotational distance. Hence, if the rotational speed is determined to be sufficiently high such that the pre-determined threshold value is exceeded, immediate "full on" or "full off is controlled. The second scheme, which is applied if the rotational speed is sufficiently low, may be any one of the control schemes mentioned above.

The control device 100 may transmit control signals to the light source 12 in different ways. According to one embodiment the control signal is determined once the user has performed the entire rotational movement. Hence, the controller 108 receives all input and determines the corresponding control signal before the control signal is transmitted.

In other embodiments a plurality of control signals are transmitted during the rotational movement. For example, once the rotational direction is determined the controller 108 may command a control signal requiring slow start of dimming. As the rotational direction is known, the control signal includes information if the light intensity should be increased or decreased. As soon as the rotational movement is finished the controller may determine the remaining properties of the intended dimmer action, i.e. the desired light intensity level. The desired light intensity level may be determined according to any of the control schemes described above, and may be determined based on angular distance, rotational speed, etc.

Determining the rotational movement of control device 100 requires the electronics of the control device 100 to be turned on. As the control device 100 however is used only for short times a limited number of times each day, it may be desirable to allow for a sleep mode in order to save power and increase battery life time. Other options are of course also possible, such as allowing for power charging of the battery 120.

Instead of a traditional on/off button on the control device 100, a switch may be provided which turns on the electronics when activated. The switch may be formed in various ways. For example, two electrodes provided at the periphery of the control device may be separated, but bridged when a user grips the control device 100. For this the position of the electrodes may be indicated in either shape or color for directing the user to use that particular grip. Once the electrodes are bridged a relay may be closed for powering the sensors 102, 104, the controller 108, and the radio communication unit 106 such that control is allowed. The relay may be provided with a timer for automatically shutting off the electronics after a

predetermined period of time.

Now turning to Fig. 4 a stack of three control devices 100 is shown. The control devices 100 are actually attached to each other by means of their respective magnets 140 such that all control devices 100 will rotate with each other. As each control device 100 may be associated with its unique light source 12, this magnetic connection in fact allows a single rotational movement of a control device 100 to actually perform dimming of a number of light sources 12.

In Fig. 5 another embodiment of a lighting system is shown, in which the magnet 140 of the control device is used to attach the control device to its associated light source 12. For such attachment, a support 200 is used. The support 200 has means for attaching the support 200 to a part of the light source 12, and a magnet which is allowed to rotate relative the remaining parts of the support 200. The control device 100 is consequently attached to the movable magnet of the support 200, such that the control device 100 may be turned relative the light source 12.

As can be seen in Fig. 5 the control device 100 is aligned in a vertical direction.

Hence, the control device state sensor 104, which may be a tilt sensor in accordance with the description above, is in this embodiment detecting vertical arrangement of the control device 100, or that the acceleration vector corresponds to a static position of the control device. The controller 108 may thus be configured to determine that the vertical position of the control device 100 is equal, or similar, to a pre-programmed vertical operating position. The support 200 may also be used to attach the control device 100 to other structures such as walls etc, or the magnet 140 of the control device 100 may be used for direct attachment to magnetic surfaces such as fridge doors etc.

In a specific embodiment, an additional magnetic sensor may be provided. The magnetic sensor, arranged in the same manner as the rotational sensor 102 and the control device state sensor 104 in terms of location, powering and connection to the controller 108, will act as a position sensor in accordance with the following. The magnetic sensor is configured to detect an external magnetic field, i.e. a magnetic field being different from the magnetic field provided by the magnet 140 of the control device. The sensed external magnetic field will provide an indication of that the magnet 140 of the control device is actually attached to an external magnet. In such position, the controller 108 will in fact determine that the control device 100 is arranged in a pre-programmed position whereby control of the dimmer circuit 20 is allowed. The exact position of the control device 100 may thus not need to be determined, but only that it is positioned adjacent to an external magnet. Hence, the support magnet (generating the external magnetic field and used for attaching the control device 100) can thus be arranged in any tilt angle, still allowing the control device 100 to provide control signals for the dimmer circuit 20.

The description above thus disclose a control device 100 for a lighting system 10 which is improved in relation to the prior art. Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims.