Lighting device arranged to be controlled via a wireless controller

Abstract

A lighting device arranged to be controlled via a wireless controller, wherein said lighting device comprises a light emitting load arranged for emitting light, a driver arranged for receiving a supply voltage and for driving said light emitting load based on said received supply voltage, an auxiliary supply arranged for supplying an auxiliary Direct Current, DC, supply voltage, a wireless receiver, connected to and powered by said auxiliary supply, arranged for wirelessly receiving, from said wireless controller, a control signal, and for activating said driver based on said received control signal, wherein said wireless receiver is arranged to operate according to a pulsed listen mode, said pulsed listen mode comprising active phases in which said wireless receiver is able to receive said control signal and non-active phases in which said wireless receiver is not able to receive said control signal.

Claims

1. A lighting device comprising: a light emitting load arranged for emitting light, a driver arranged for receiving an AC supply voltage and for driving the light emitting load based on the received supply voltage, an auxiliary supply arranged for supplying an auxiliary supply voltage, and a wireless receiver implemented in a microcontroller, connected to and powered by the auxiliary supply, wherein the wireless receiver is arranged for wirelessly receiving a control signal from a wireless controller, and arranged for activating the driver based on the received control signal, a wireless transmitter embedded in the microcontroller and arranged for wirelessly transmitting an acknowledgement message to said wireless controller upon correct receipt of said control signal, and wherein the wireless receiver is arranged to operate according to a pulsed listen mode, the pulsed listen mode comprising active phases in which the wireless receiver is able to receive the control signal and non-active phases in which the wireless receiver is not able to receive any communication from the wireless controller, and wherein commencement of the active phases are determined based upon an identifiable reference point of the AC supply voltage waveform.

2. The lighting device according to claim 1, wherein said pulsed listen mode comprises a repetitive pattern of subsequent pulses, wherein said pulse listen mode is in an active phase during a pulse and in a non-active phase between subsequent pulses.

3. The lighting device according to claim 2, wherein said pulsed listen mode comprises a duty cycle between 5%-15%, and wherein a duration of a pulse is between 30 ms 100 ms.

4. The lighting device according to claim 1, wherein said driver is further arranged to convert said AC supply voltage to an DC voltage, and for providing said DC voltage to said wireless receiver for additionally empowering said wireless receiver.

5. The lighting device according to claim 1, wherein said auxiliary supply is a capacitive supply.

6. The lighting device according to claim 1, wherein said identifiable reference point is based on at least one of: a phase of said mains power supply; a cycle of said mains power supply.

7. A lighting assembly, comprising: a lighting device according to claim 1, and a wireless controller arranged for wirelessly transmitting a control signal to said lighting device, wherein said wireless controller is arranged to repeatedly transmit the same control signal to said lighting device thereby ensuring that said wireless receiver has received said control signal.

8. A method of operating a lighting device, the lighting device having an AC supply voltage for providing power via a driver to a light emitting load, a wireless receiver implemented in a microcontroller and arranged for wirelessly receiving a control message from a wireless controller, and a wireless transmitter implemented in a microcontroller and arranged for wirelessly transmitting an acknowledgement message to said wireless controller; wherein said method comprises the steps of: activating said wireless receiver during active phases of said pulse listen mode such that said wireless receiver is able to receive said control signal, wherein commencement of the active phases are determined based upon an identifiable reference point of the AC supply voltage waveform, and deactivating said wireless receiver during non-active phases of said pulse listen mode such that said wireless receiver is not able to receive any communication from the wireless controller, receiving, by an activated wireless receiver, said wireless control signal from said wireless controller, transmitting an acknowledgement message to said wireless controller, and activating, by said wireless receiver, said driver based on said received control signal such that said light emitting load of said lighting device starts emitting light.

9. The method according to claim 8, wherein said pulsed listen mode comprises a repetitive pattern of subsequent pulses, wherein said pulse listen mode is in an active phase during a pulse and in a non-active phase between subsequent pulses.

10. The method according to claim 9, wherein said pulsed listen mode comprises a duty cycle between 5%-15%, and wherein a duration of a pulse is between 30 ms 100 ms.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a lighting device according to an embodiment of the present disclosure.

(2) FIG. 2 shows a simplified diagram illustrating an example of a pulsed listen mode as defined in the present disclosure.

(3) FIG. 3 shows a simplified slow chart diagram illustrating an example of the steps performed in accordance with an embodiment of the present disclosure.

(4) FIG. 4 shows a simplified flow chart diagram illustrating an example of a synchronization scheme for the wireless receiver and the mains power supply.

DETAILED DESCRIPTION

(5) Reference numeral 1 in FIG. 1 designates a lighting device arranged to be controlled via a wireless controller. More specifically, in the present example, the lighting device is a retrofit Light Emitting Diode, LED, lamp. A LED lamp is retrofitted in case it fits in conventional armatures for conventional incandescent or halogen lamps. In order to fit in these conventional armatures, the retrofit LED lamp 1 comprises conducting pens for connecting, and supporting, the retrofit LED lamp 1 in the conventional armatures.

(6) The retrofit LED lamp 1 comprises a light emitting load 9, more specifically an LED array 9, for emitting light. The LED array 9 may comprise a plurality of series and parallel connected LED's. Those skilled in the art will appreciate that in practical embodiments the LEDs are evenly distributed and spaced apart across the length of the lamp 1, to provide for an evenly as possible lighting by the LED lamp 1 over its entire length. The present disclosure is not limited to any specific type of LED, nor to any color LEDs. Typically, white colored LEDs are used.

(7) The retrofit LED lamp 1 comprises a driver 10 arranged for receiving a supply voltage and for driving the light emitting load 9 based on the received supply voltage. It is noted that the driver may directly receive an Alternating Current, AC, supply voltage, but may also receive a Direct Current, DC, supply voltage. In the present example, a rectifier 2 is provided in the retrofit LED lamp 1.

(8) The rectifier 2 has an input and an output, wherein the rectifier 2 is arranged to receive an AC mains supply voltage at its input, to convert the AC supply voltage to a DC voltage, and to provide the DC voltage to the driver 10. The rectifier 2 comprises for example four diodes for rectifying the AC voltage to a DC voltage.

(9) The mains AC supply voltage is indicated with reference numeral 3. The AC supply voltage 3 is provided to the retrofit LED lamp 1 via a socket. Such a socket is, for example, a traditional socket which is also used for connecting fluorescent tubes.

(10) The retrofit LED lamp 1 may further comprise a capacitor 4 for further rectifying the DC voltage which is outputted by the rectifier 2. The capacitor 4 may thus function as some sort of buffer to make sure that the DC voltage does not fluctuate too much.

(11) Further, an auxiliary supply 5 is provided which is arranged for supplying an auxiliary Direct Current, DC, supply voltage. The auxiliary supply 5 is shown as a block diagram. Typically, a capacitor is provided in the block diagram, which capacitor acts as a storage unit for providing the DC supply voltage. Further, logics may be provided to make sure that the auxiliary supply is recharged whenever the retrofit LED lamp 1 is turned on, and that the auxiliary supply is not recharged whenever the retrofit LED lamp 1 is turned off.

(12) A Zener diode 13 may be provided at the output of the auxiliary supply 5 to make sure that the DC supply voltage provided by the auxiliary supply 5 is more or less a steady voltage. Further, a capacitor 12 may be provided to further stabilize the DC supply voltage.

(13) The retrofit LED lamp 1 further comprises a wireless receiver 11, connected to and powered by the auxiliary supply 5, which wireless receiver 11 is arranged for wirelessly receiving, from the wireless controller, a control signal, and for activating the driver 10 based on the received control signal.

(14) The wireless receiver 11 depicted in FIG. 1 is shown as a block diagram. It is noted that, typically, the wireless receiver is a wireless receiving function embodied in a micro controller or a microprocessor. The wireless receiving function may alternatively be embodied in a Field Programmable Gate Array, FPGA.

(15) One of the aspects of the present disclosure is that the wireless receiver 11 is operating according to a pulsed listen mode, wherein the pulsed listen mode comprises active phases in which the wireless receiver 11 is able to receive the control signal and non-active phases in which the wireless receiver 11 is not able to receive the control signal.

(16) Following the above, it is noted that the wireless receiver 11 is deactivated during the non-active phases such that the wireless receiver 11 consumes less power compared to the situations in which the wireless receiver 11 is activated, i.e. during the active phases.

(17) As such, at least in situations in which the retrofit LED lamp 1 is not emitting light, the total power consumption of the retrofit LED lamp 1 is reduced. It is further noted that the remaining functionality of the retrofit LED lamp 1, like the driver, other functionality comprised in the same micro controller may be shut off. This further reduces the power consumption of the retrofit LED lamp 1.

(18) In accordance with the present disclosure, a pulsed listen mode means that the wireless receiver is alternately in a listening mode, i.e. in a mode in which it is receptive for control signals, and in a silent mode, i.e. in a mode in which it is not receptive for control signals. During the silent mode, the wireless receiver 11 consumes less power compared to the same wireless receiver 11 in the listening mode.

(19) The inventors have found that the wireless receiver 11 does not need to be active all the time to make sure that the control signal is sent. Typically, the wireless receiver needs to have a duty cycle of about 5%-15%, and a pulse duration of about 30 ms-100 ms, to make sure that there is a high probability that any control signal that is transmitted is also correctly received.

(20) The retrofit LED lamp 1 further comprises a diode 6 which is used to recharge the auxiliary supply 5 in situations in which the driver is active, i.e. in which the light emitting load 9 is actually emitting light. The output of the driver 10 is then fed back to the auxiliary supply 5 via the diode 6.

(21) FIG. 1 further shows a wireless controller 8 in the form of a remote controller 8 and a wireless access point 7 which is used for communication between the retrofit LED lamp 1 and the remote controller 8.

(22) The remote controller 8 may send the control signal repeatedly to make sure that the retrofit LED lamp 1 will correctly receive the transmitted control signal. This is especially true for the present disclosure as the wireless receiver 11 of the retrofit LED lamp 1 is operating according to the pulsed listen mode. That is, the wireless receiver 11 is not able to receive any transmitted signal in between the pulses of the pulsed listen mode, i.e. in situations in which the wireless receiver 11 is deactivated.

(23) As further depicted in FIG. 1, it is noted that the micro controller 14 which embeds the receiving function of the wireless receiver H as explained above, may further embed a wireless transmitter 15. The wireless transmitter is used for transmitting an acknowledgement message back to the wireless controller for indicating, to the wireless controller, that the control signal is correctly received. Based upon receipt of the acknowledgement message, by the wireless controller, the wireless controller may cease in repeatedly transmitting the control signal.

(24) It is noted that, in accordance with the present disclosure, a housing may be provided for housing the retrofit LED lamp 1. The housing is schematically indicated with the circle which encloses each of the components shown in FIG. 1. The housing may be a light transmissive housing or a partly transmissive housing, configured as a retrofit tube type, for example.

(25) FIG. 2 shows a simplified diagram 101 illustrating an example of a pulsed listen mode as defined in the present disclosure.

(26) Here, the vertical axis indicates whether the receiver, i.e. the receiving function, is activated or whether the receiver is deactivated. In case the pulse is high, the receiver is activated; in case the pulse is low, the receiver is deactivated.

(27) In the present example, four pulses are shown wherein one pulse is referenced to with reference numeral 103. The pulse has a pulse width as indicated with reference numeral 102 and has a certain dead time which is indicated with reference numeral 104. It is noted that during the dead time, i.e. the non-active phase, the receiver is not active. This means that the receiver is not able to receive any control signals during this time. The effect hereof is that the receiver is hardly consuming any power such that the total amount of power is reduced significantly.

(28) The pulse width 102 is, preferably, about 30 ms-100 ms. The inventors have found that such a pulse width 102 is more than sufficient to receive a control signal. The receiver should be able to receive the control signal with that amount of time. This should be doable as the control signal is typically a very light weighted message. It is noted that the message, in an embodiment, only has to convey an activation signal such that the message does not have to be lengthy.

(29) The horizontal axis 106 is directed to the time. As such, here, four pulses are received within the time windows displayed. The pulses are, in this particular example, spaced apart evenly. It is however also conceivable that the pulses are not spaced apart evenly, but, for example, randomly or anything alike. Preferably the length of a pulse is tuned to the length of the message of the control signal. This ensures that the power consumed by the receiver is reduced even further.

(30) It is noted that the width of the pulses shown in FIG. 2 are also equal. It is however also conceivable that the width of the pulses is not the same for each pulse. For example, it may be decided to amend the width of the pulses randomly between two values. This could further improve the robustness of the system.

(31) FIG. 3 shows a simplified flow chart diagram 201 illustrating an example of the steps performed in accordance with an embodiment of the present disclosure.

(32) A method of operating a lighting device according to any of the examples as provided above.

(33) The method comprises the steps of:

(34) activating 202 said wireless receiver during active phases of said pulse listen mode such that said wireless receiver is able to receive said control signal, and

(35) deactivating 203 said wireless receiver during non-active phases of said pulse listen mode such that said wireless receiver is not able to receive said control signal,

(36) receiving 204, by an activated wireless receiver, said wireless control signal from said wireless controller, and

(37) activating 205, by said wireless receiver, said driver based on said received control signal such that said light emitting load of said lighting device starts emitting light.

(38) Following the above, the method starts with alternatingly activating and deactivating the receiver according to the pulsed listen mode that is set. An activated receiver is able to receive messages; a deactivated receiver is not able to receive any messages.

(39) At a certain point in time, the wireless receiver will receive a wireless control signal from the wireless controller. It is noted that the receipt of such a message can only occur in situations wherein the wireless receiver is activated, i.e. it is an activated wireless receiver.

(40) Once the control signal has been received, the wireless receiver may activate the driver such that the lighting device starts to emit light. The driver will then enable the mains supply voltage, such that the energy is not drawn from the auxiliary supply but from the mains supply voltage. Further, the driver may be arranged to convert the received mains supply voltage to a DC voltage which is suitable to recharge the auxiliary supply.

(41) It is noted that, in accordance with the present invention, the wireless receiver is powered by the auxiliary supply in situations wherein the lighting device does not emit light. Such a condition may, however, occur for a particularly long time such that there could be a risk that the auxiliary supply runs out of energy.

(42) To combat such a risk, the wireless receiver may be equipped with a safety mechanism. The safety mechanism may initiate in case the voltage provided by the auxiliary supply falls below a predetermined supply voltage. In such situations, the wireless receiver may enable the driver for recharging the auxiliary supply only. As such, the driver does not drive the light emitting load but it only provides a DC output voltage for recharging the auxiliary supply. Alternatively, the wireless receiver may enable another rectifier for recharging the auxiliary supply.

(43) FIG. 4 shows a simplified flow chart diagram 301 illustrating an example of a synchronization scheme for the wireless receiver and the mains power supply.

(44) Here, two synchronization principles are shown. On the left, as indicated with reference numeral 302, a mains power supply voltage is shown. For example, an Alternating Current, AC, voltage of 230 Vac or anything alike. On the right, as indicated with reference numeral 303, a similar mains power supply voltage is shown. On the left 302, an active phase of the wireless receiver is indicated with reference numeral 304. In this particular case, the active phase 304 is active during a full cycle of the mains power supply. The wireless receiver is then deactivated for, for example, a couple of cycles of the mains power supply. In this particular situation, the start moment of the active phase corresponds to the highest voltage of the AC power supply. Such a construction can be construed using an operational amplifier.

(45) On the right, i.e. as indicated with reference numeral 303, another synchronization scheme is shown. Here, the active phase 305 of the wireless receiver is active for about half of the total period of the cycle of the mains power supply. The active phase may then be repeated for the next cycle having the same, or another, trigger point.

(46) It is noted that in the above described examples, the starting point, i.e. the trigger moment, of the active phase of the wireless receiver equals the top voltage of the AC power supply. It is noted that, in other situations, a zero crossing aspect or reference may be used as a trigger moment for synchronization.

(47) Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope thereof.