WO2025051569A1

WO2025051569A1 - Methods for regulating turn-on and turn-off illumination of led luminaires to correspond to incandescent luminaire illumination

Info

Publication number: WO2025051569A1
Application number: PCT/EP2024/073777
Authority: WO
Inventors: Raymond George JANIK; Daniel Leland BRAGG
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2023-09-07
Filing date: 2024-08-26
Publication date: 2025-03-13
Anticipated expiration: 2026-03-07

Abstract

A method for controlling a light emitting diode is provided. The method includes receiving, by a controller, an indication of a turn-on or turn-off event for the light emitting diode. The method further includes providing, by the controller, a control signal, based on the received indication, to control an amount of current delivered to the light emitting diode during the turn-on or turn-off event. The control signal is based on a first curve or a second curve. The first curve is configured to provide a gradual increase in light intensity output by the light emitting diode after the turn-on event. The second curve is configured to provide a gradual decrease in light intensity output by the light emitting diode after the turn-off event. Both curves are designed to enable the control signal to configure to the light emitting diode to match the behavior of an incandescent light. Both curves are scaled to match a dimmer setting.

Description

Methods for regulating turn-on and turn-off illumination of LED luminaires to correspond to incandescent luminaire illumination

FIELD OF THE INVENTION

The present disclosure is generally directed to regulating turn-on and turn-off transitions of light emitting diode (LED) luminaires to correspond to incandescent luminaire illumination.

BACKGROUND OF THE INVENTION

Turn-on and turn-off transitions of light emitting diode (LED) luminaires are governed by energy storage devices in driver output circuits, such as capacitors or inductors. These energy storage devices may cause inconsistencies and random behavior in the turn-on or turn-off transitions of the LED luminaires. For example, the time required to fully charge a capacitor of the driver output circuit may lead to a delay in the turn-on transition. Further, following this delay, the LED luminaire typically turns fully on in an undesirable manner, rather than the more aesthetically pleasing gradual turn-on reminiscent of incandescent luminaires.

SUMMARY OF THE INVENTION

The present disclosure is generally directed to regulating turn-on and turn-off transitions of light emitting diode (LED) luminaires to correspond to incandescent luminaire illumination. In particular, the present disclosure provides a controller configured to receive an indication signal from an LED driver indicative of a turn-on event or a turn-off event. A turn-on event or a turn-off event corresponds to the LED driver beginning to receive (or no longer receiving) an alternating current (AC) input signal from a power source. In the case of a turn-on event, the controller retrieves stored pulse width modulation (PWM) data from a look-up table. The PWM data defines one or more curves representing a gradual increase in light intensity output. The controller then applies a control signal incorporating the PWM data to a DC-to-DC converter. Based on the received PWM data, the DC-to-DC converter controls the current provided to one or more LEDs to implement the gradual increase in light intensity output. Similarly, in the case of a turn-off event, the controller retrieves PWM data from the look-up table defining a curve representing a gradual decrease in light intensity output. A control signal incorporating the retrieved PWM data is applied to the DC-to-DC converter to implement the gradual decrease in light intensity output. The gradual increase or decrease in light intensity output is configured to match behavior of an incandescent light.

In some examples, the stored PWM data is selected based on the output power provided to the LEDs by the LED driver. This output power may be pre-programmed into a memory of the controller. In other examples, the output power may be measured by the controller. Generally, the time required for the gradual increase or decrease in light intensity is directly related to the output power, such that higher output power luminaires require more time for the gradual increase or decrease in light intensity. The time duration of the gradual increase or decrease typically ranges between 100 milliseconds and 500 milliseconds.

The controller may be further configured to receive dimmer information from the LED driver. The dimmer information corresponds to a dimming level implemented by the LED driver. The controller may use this dimmer information to scale the curve used to implement the gradual increase or decrease in light intensity. In some examples, if the dimmer information is received by the controller while the gradual increase or decrease is occurring, only a portion of the curve may be scaled.

Generally, in one example, a method for controlling an LED is provided. The method includes receiving, by a controller, an indication of a turn-on or turn-off event for the LED.

The method further includes providing, by the controller, a control signal, based on the received indication, to control an amount of current delivered to the LED during the turn-on or turn-off event. The control signal is based on a first curve or a second curve. The first curve is configured to provide a gradual increase in light intensity output by the LED after the turn-on event. The second curve is configured to provide a gradual decrease in light intensity output by the LED after the turn-off event to match behavior of an incandescent light.

According to an example, the first curve is configured to provide the gradual increase in light intensity output to match an increase in intensity in light intensity output of the incandescent light from a zero output to a steady-state output.

According to an example, the second curve is configured to provide the gradual decrease in light intensity output to match a decrease in light intensity output of the incandescent light from a steady-state output to a zero output. According to an example, the control signal is provided prior to power being sent to the LED.

According to an example, the method further includes (1) determining, by the controller, a power level of the LED; and (2) selecting, by the controller, pulse width modulation data stored in a look-up table, based on the power level of the light emitting diode, wherein the pulse width modulation data corresponds to the first curve or the second curve from a plurality of curves.

According to an example, the first curve and the second curve are defined by pulse width modulation data stored in a look-up table accessible by the controller.

According to an example, the first curve and the second curve are based on a power level of the incandescent light that is being matched. The power level of the incandescent light that is being matched is pre-programmed on the controller.

According to an example, the method further includes (1) receiving, by the controller, dimmer information for the LED along with the indication of the turn-on event or the turn-off event; and (2) scaling, by the controller, the first curve to provide the gradual increase in the light intensity output by the LED after the turn-on event or the second curve to provide the gradual decrease in the light intensity output by the LED after the turn-off event based on the dimmer information.

According to an example, the method further includes (1) receiving, by the controller, a change in the dimmer information for the LED when the LED is receiving power; (2) selecting, by the controller, a portion of the curve based on the change in the dimmer information; and (3) providing, by the controller, a control signal to control the amount of current delivered to the LED based on the selected portion of the curve configured to adjust the light intensity output by the LED based on the change in the dimmer information.

According to an example, the gradual increase or the gradual decrease in the light intensity output occurs over a time duration less than or equal to 500 milliseconds. A correlated color temperature output by the LED may increase or decrease during the time duration.

Generally, in another example, a light fixture system is provided. The light fixture system includes an LED.

The light fixture system further includes a controller coupled to the LED. The controller is configured to receive an indication of a turn-on or turn-off event for the LED. The controller is further configured to provide a control signal, based on the received indication, to control an amount of current delivered to the LED during the turn-on or turn-off event. The control signal is further based on a first curve configured to provide a gradual increase in light intensity output by the LED after the turn-on event or a second curve configured to provide a gradual decrease in light intensity output by the LED after the turnoff event to match behavior of an incandescent light.

According to an example, the light fixture system further includes a plurality of LEDs. The controller is configured to provide the control signal to each of the plurality of the LEDs.

According to an example, the light fixture system further includes a set of pulse width modulation data stored in a look-up table from which the pulse width modulation data defining the first curve and the second curve can be selected.

According to an example, the light fixture system further includes a driver coupled to the controller. The driver is configured to provide the indication of the turn-on event or the turn-off event to the controller.

It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiment s) described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the various embodiments.

FIG. l is a schematic of a light fixture system, according to aspects of the present disclosure.

FIG. 2 is a flowchart of a method for controlling a light emitting diode, according to aspects of the present disclosure. FIG. 3 is a flowchart of further steps of the method for controlling a light emitting diode, according to aspects of the present disclosure.

FIG. 4 is a series of curves for configuring a control signal to gradually increase light intensity output for three different output power levels, according to aspects of the present disclosure.

FIG. 5 is a series of curves for configuring a control signal to gradually increase light intensity output for two different dimming levels, according to aspects of the present disclosure.

FIG. 6 is a curve for gradually decreasing correlated color temperature of a light emitting diode, according to aspects of the present disclosure.

FIG. 7 is a schematic of a controller for controlling a light emitting diode, according to aspects of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Turning now to the figures, FIG. 1 illustrates a schematic of a light fixture system 10. Broadly, the light fixture system 10 includes a controller 100, one or more LEDs 200, an LED driver 300, and a direct current (DC)-to-DC converter 400. The LED driver 300 is a circuit configured to convert an AC input 12 to a DC output voltage 306, as the LEDs 200 require DC current to illuminate. In some examples, the AC input 12 may be received from a mains power source, such as a wall outlet. The AC input 12 may be controlled via mechanical means, such as a wall switch, or via electronic means, such as a mobile application run on a mobile device. The output voltage 306 is then provided to the DC-to-DC voltage-to-current converter 400 to generate a PWM current 402. The PWM current 402 is then provided to LEDs 200 to generate illumination. The light intensity output of the LEDs 200 is controlled by a duty cycle of the PWM current 402.

The LED driver 300 further receives a dimming input 14. The dimming input 14 may be received from a dimmer switch, such as a wall-mounted dimmer dial. In some cases, the dimming input 14 may directly correspond to the duty cycle of the PWM current 402 to control the light intensity output of the LEDs 200. For example, setting the dimming input to 50% may result in the PWM current 402 having a duty cycle of 50%, thereby adjusting the light intensity output to match the desired dimming level. In some examples, the dimmer input 14 may be received from a remote source, such as a mobile application running on a smartphone. In this case, the LED driver 300 may then use a wireless transceiver to receive the dimmer input 14. Dimming may also be accomplished by a phase-cut dimmer connected to the AC input.

The controller 100 is configured to receive a variety of inputs and data from the LED driver 300 to generate a PWM control signal 102. The controller 100 is shown in more detail in FIG. 7, and generally includes a processor 125, a memory 175, and a communications interface 185. The PWM control signal 102 is provided to the DC-to-DC converter 400 to configure the PWM current 402. The PWM control signal 102 is a time varying signal configured to adjust the duty cycle of the PWM current 402 to gradually increase or gradually decrease the light intensity output of the LEDs 200. In this way, the LEDs 200 will gradually increase or decrease light intensity output in a manner similar to incandescent luminaires.

The controller 100 is configured to receive an indication 302 of a turn-on or turn-off event. A turn-on event corresponds to the LED driver 300 initially receiving the AC input 12, such as when a user initially flips a wall switch to the ON position. A turn-off event corresponds to the LED driver 300 no longer receiving the AC input 12, such as when the user flips the wall switch to the OFF position.

Receiving the indication 302 triggers the controller 100 to generate the PWM control signal 102. The PWM control signal 102 is generated based on a look-up table 104. The look-up table 104 includes a range of PWM data 110 that define curves 106 corresponding to a range of power levels 108. Each of the curves 106 may correspond to a gradual increase or a gradual decrease in light intensity output (flux) over time. Further, some of the curves 106 may correspond to a gradual increase or a gradual decrease in correlated color temperature (CCT) over time. Examples of these curves 106 are illustrated in FIGS. 4- 6.

The controller 100 selects the PWM data 110 from the look-up table 104 based on the type of indication 302 (turn-on or turn-off) and power level information 308 associated with fully illuminating the LEDs 200. In some examples, the power level 308 is preprogrammed into the memory 175 of the controller 100. In other examples, the power level information 308 is provided to the controller 100 via the LED driver 300. In some examples, the power level information 308 may be provided in the form of a power level 310, such as 25 watts. In other examples, the power level information 308 may be provided in terms of the voltage level of the AC input 12 or the voltage level of the output voltage 306, enabling the controller 100 to determine the power level based on these voltage levels. Once the power level 310 for fully illuminating the LEDs 200 is determined, a corresponding power level 108 is located in the look-up table 104 to identify the appropriate curve 106 to gradually increase or decrease the light intensity output of the LEDs 200.

The time duration for the curves 106 to gradually increase or gradually decrease is typically between 100 milliseconds and 500 milliseconds. Further, higher power level incandescent luminaires typically gradually increase or decrease light intensity output over a longer time duration than lower power incandescent luminaires due to variations in filament mass. Accordingly, the curves 106 of the look-up table 104 reflect these time duration variations.

The controller 100 may further receive dimmer information 304 from the LED driver 300. The dimmer information 304 corresponds to the dimming input 14 received by the LED driver 300. As will be demonstrated with respect to FIG. 5, the dimmer information 304 may be used to scale up or down all or a portion of the selected curve 106 used to generate the PWM control signal 102.

Accordingly, the controller 100 generates the PWM control signal 102 based on a combination of the indication 302 of the turn-on or turn-off event, the power level information 308, and, optionally, the dimmer information 304. The PWM control signal 102 (incorporating the PWM data 110 selected from the look-up table 104) is then provided to the DC-to-DC converter 400. The DC-to-DC converter 400 then generates a PWM current 402 to illuminate the LEDs 200 according to the PWM control signal 102. Thus, as duty cycle of the PWM control signal 102 increases and/or decreases according to the curve 106, the duty cycle of the PWM current 402 similarly increases or decreases over time, resulting in the gradual increase or decrease in light intensity output by the LEDs 200. In some example, the PWM control signal 102 may be provided to each of the LEDs 200 individually.

FIG. 2 illustrates a flowchart of a method 900 for a method for controlling an LED 200. In some examples, the LED 200 is embodied as a plurality of LEDs 200. The method 900 includes, in step 902, receiving, by the controller 100, the indication 302 of the turn-on or turn-off event for the LED 200. As shown in FIG. 1, the indication 302 may be provided to the controller 100 by the LED driver 300.

As shown in FIG. 2, the method 900 further includes, in step 904, providing, by the controller 100, a PWM control signal 102, based on the received indication 302, to control an amount of current delivered to the LED 200 during the turn-on or turn-off event. The indication 302 is received by the controller 100 prior to the LEDs 200 being illuminated by the PWM current 402. In some examples, the controller 100 receives the indication 302 within microseconds (such as less than 100 microseconds) of the turn-on or turn-off event.

The PWM control signal 102 is based on the first curve 106a or the second curve 106b. The first curve 106a is configured to provide a gradual increase in light intensity output by the LED 200 after the turn-on event. In some examples, the gradual increase provided by the first curve 106a matches an increase in light intensity output of an incandescent luminaire from a zero output to a steady-state output. Example of these curves 106a are shown in FIGS. 4 and 5. The second curve 106b is configured to provide a gradual decrease in light intensity output by the LED 200 after the turn-off event to match behavior of an incandescent light. In some examples, the gradual decrease provided by the second curve 106a matches an increase in light intensity output of an incandescent luminaire from a steady-state output to a zero output.

According to an example, the method 900 may further include, in optional step 906, determining, by the controller 100, a power level 310 of the LED 200. The power level 310 may be preprogrammed into the memory 175 of the controller 100, or the power level 310 may be determined based on power level information 308 provided by the LED driver 300 to the controller 100. Further, the method 900 may also include, in optional step 908, selecting, by the controller 100, PWM data 110 stored in a look-up table 104, based on the power level 310 of the LED 200, wherein the PWM data 110 corresponds to the first curve 106a or the second curve 106b from a plurality of curves 106. FIG. 3 illustrates a flowchart of further optional steps of the method 900 for controlling the LED 200. The method 900 may include, in optional step 910, receiving, by the controller 100, dimmer information 304 for the LED 200 along with the indication 302 of the turn-on event or the turn-off event. The method 900 may further include, in optional step 912, scaling, by the controller 100, the first curve 106a to provide the gradual increase in the light intensity output by the LED 200 after the turn-on event or the second curve 106 to provide the gradual decrease in the light intensity output by the LED 200 after the turn-off event based on the dimmer information 304.

According to another example shown in FIG. 3, the method 900 may further include, in optional step 914, receiving, by the controller 100, a change in the dimmer information 304 for the LED 200 when the LED 200 is receiving power. The method 900 may further include, in optional step 916, selecting, by the controller 100, a portion of the curve 106 based on the change in the dimmer information 304. The method 900 may further include, in optional step 918, providing, by the controller 100, a PWM control signal 102 to control the amount of current delivered to the LED 200 based on the selected portion of the curve 106 configured to adjust the light intensity output by the LED based on the change in the dimmer information 304. Thus, if the dimmer information 304 is adjusted during illumination according to the selected curve 106, only the remaining portion of the curve is adjusted. For example, in response to an indication 302 of a turn-on event, the first curve 106a may be selected from the loop-up table 104 based on the power level information 308 stored in or received by the controller 100. The first curve 106a may gradually increase light intensity output over a time duration of 400 milliseconds. The first curve 106a has been scaled according to dimmer information 304 corresponding to a dimming level of 50% illumination. At the 200 millisecond point of the gradual intensity increase, a user may adjust the dimming level to 75% illumination. Thus, the controller 100 may then scale up the portion of the first curve 106a after 200 milliseconds, rather than the entire first curve 106a.

FIG. 4 is a series of first curves 106a for configuring the PWM control signal 102 to gradually increase light intensity output (referred to as flux in the plot of FIG. 4) for three different output power levels 310. The series of first curves 106a includes a low power curve 106al corresponding to a low output power level 310, a medium power curve 106a2 corresponding to a medium output power level 310, and a high-power curve 160a3 corresponding to a high output power level 310. As shown in FIG. 4, the time duration required for the curves 106a to reach a steady state increases with the output power level 310. Accordingly, the low power curve 106al reaches a steady state at a time of t_pi, the medium power curve 106a2 reaches a steady state at a time of t_P2, and the high-power curve 106a3 reaches a steady state at a time of t_ps. Therefore, in order to match the gradual increasing illumination of an incandescent luminaire after a turn-on event, high-power LEDs 200 will take longer to fully illuminate than low power LED 200s. This relationship is further explained in Tables 1 and 2 below:

Table 1

Table 2

Table 1 illustrates how flux (intensity) varies over time for the example first curves 106a of FIG. 4. In particular, Table 1 shows how various values of flux (0o, 0i, 0_n-i, 0_n) map onto points in time (to, 6, L, L). These points in time may be shifted according to a time-coefficient (a). Table 2 applies the information of Table 1 to four example incandescent luminaires of various power levels. Each of the four power levels is associated with a timecoefficient value. The time-coefficient value is multiplied by a baseline time duration of a gradual intensity output increase or decrease to determine the time period associated with a specific power level. For example, if a 50-watt incandescent luminaire has a time duration of 100 milliseconds, according to Table 1, a 25-watt luminaire will have a shorter time duration of 90 milliseconds, while a 100-watt luminaire will have a longer time duration of 110 milliseconds.

FIG. 5 illustrates a pair of curves 106a4, 106a5 for configuring the PWM control signal 102 to gradually increase light intensity output for two different dimming levels. As shown in FIG. 5, a fully illuminated curve 106a4 and a half-dimmed curved 106a5 both reach their steady state at a time of t_P2. However, at t_P2, the output flux (or intensity) of the half-dimmed curve 106a5 is approximately half of the output flux of the fully illuminated curve 106a4.

The half-dimmed curve 106a5 is approximately half of the output flux of the fully illuminated curve 106a4 throughout the entire time period shown in FIG. 5. Accordingly, the dimming level was likely set prior to the turn-on event leading to the gradual increase in output flux. However, if the dimming level is changed during the gradual increase, only the remaining portion of the curve 106 should be adjusted. This is illustrated by partially dimmed curve 106a6. In the example of curve 106a6, the dimming level is changed from fully illuminated to half-dimmed at a time of t_pi. Thus, only the portion of the curve 106a6 following a time of t_pi is scaled down to correspond with the dimming level, rather than the entire curve.

In some examples, the curve 106 configuring the PWM control signal 102 may be based on a relationship of correlated color temperature, rather than intensity or flux, over time. FIG. 6 illustrates a curve 106b of gradual decrease in correlated color temperature to be implemented following a turn-off event. The time duration of the gradual decrease is approximately 0.3 seconds. During this time duration, the correlated color temperature decreases from a steady state of approximately 3200 Kelvin to approximately 1400 Kelvin in a substantially linear fashion. Thus, the PWM control signal 102 based on the curve 106b will configure the LED 200 to generate a similar correlated color temperature variance over 0.3 second following a turn-off event.

FIG. 7 illustrates an example schematic of a controller 100 for controlling the output of the LEDs 200 of the light fixture system 10. Broadly, the controller 100 includes the processor 125, the memory 175, and the communications interface 185. The memory 125 is configured to store a variety of information related to the light fixture system 10, such as the PWM control signal 102, the look-up table 104 (including the PWM data 110a defining the curves 106 and their associated power levels 108), the indication 302 of a turn-on or turnoff event, dimmer information 304, and the power level information 308. The communications interface 185 is configured to enable communication between the controller 100 and the other aspects of the light fixture system 10, such as the LED driver 300 and the DC-to-DC converter 400.

All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements can optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified.

As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements can optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.

It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

The above-described examples of the described subject matter can be implemented in any of numerous ways. For example, some aspects can be implemented using hardware, software, or a combination thereof. When any aspect is implemented at least in part in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single device or computer or distributed among multiple devices/computers.

The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various examples of the present disclosure. In this regard, each block in the flowchart or block diagrams can represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks can occur out of the order noted in the Figures. For example, two blocks shown in succession can, in fact, be executed substantially concurrently, or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

Other implementations are within the scope of the following claims and other claims to which the applicant can be entitled. While various examples have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the examples described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings is/are used. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific examples described herein. It is, therefore, to be understood that the foregoing examples are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, examples can be practiced otherwise than as specifically described and claimed. Examples of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.

Claims

1. A method (900) for controlling a light emitting diode, the method comprising: receiving (902, 910), by a controller, an indication of a turn-on or turn-off event for the light emitting diode and dimmer information for the light emitting diode; scaling (912), by the controller, a first curve to provide the gradual increase in the light intensity output by the light emitting diode after the turn-on event or a second curve to provide the gradual decrease in the light intensity output by the light emitting diode after the turn-off event based on the dimmer information; and providing (904), by the controller, a control signal, based on the received indication, to control an amount of current delivered to the light emitting diode during the turn-on or turn-off event, wherein the control signal is based on the first curve configured to provide a gradual increase in light intensity output by the light emitting diode after the turnon event or the second curve configured to provide a gradual decrease in light intensity output by the light emitting diode after the turn-off event.

2. The method (900) of claim 1, wherein the first curve is configured to provide the gradual increase in light intensity output substantially similar to an increase in intensity in light intensity output of an incandescent light from a zero output to a steady-state output.

3. The method (900) of claim 1, wherein the second curve is configured to provide the gradual decrease in light intensity output substantially similar to a decrease in light intensity output of an incandescent light from a steady-state output to a zero output.

4. The method (900) of claim 1, wherein the control signal is provided prior to power being sent to the light emitting diode.

5. The method (900) of claim 4 further comprising: determining (906), by the controller, a power level of the light emitting diode; and selecting (908), by the controller, pulse width modulation data stored in a look-up table, based on the power level of the light emitting diode, wherein the pulse width modulation data corresponds to the first curve or the second curve from a plurality of curves.

6. The method (900) of claim 1, wherein the first curve and the second curve are defined by pulse width modulation data stored in a look-up table accessible by the controller.

7. The method (900) of claim 1, wherein the first curve and the second curve are based on a power level of an incandescent light pre-programmed on the controller.

8. The method (900) of claim 1 further comprising: receiving (914), by the controller, a change in the dimmer information for the light emitting diode when the light emitting diode is receiving power; selecting (916), by the controller, a portion of the first curve or second curve based on the change in the dimmer information; and providing (918), by the controller, a control signal to control the amount of current delivered to the light emitting diode based on the selected portion of the first curve or second curve configured to adjust the light intensity output by the light emitting diode based on the change in the dimmer information.

9. The method (900) of claim 1, wherein the gradual increase or the gradual decrease in the light intensity output occurs over a time duration less than or equal to 500 milliseconds.

10. The method (900) of claim 9, wherein a correlated color temperature output by the light emitting diode increases or decreases during the time duration.

11. A lighting device comprising: a light emitting diode (200); a controller (100) coupled to the light emitting diode, the controller (100) configured to: receive an indication (302) of a turn-on or turn-off event for the light emitting diode (200) and dimmer information for the light emitting diode; scale, by the controller, a first curve (106a) to provide the gradual increase in the light intensity output by the light emitting diode after the turn-on event or a second curve (106b) to provide the gradual decrease in the light intensity output by the light emitting diode after the turn-off event based on the dimmer information; and provide a control signal (102), based on the received indication (302), to control an amount of current delivered to the light emitting diode (200) during the turn-on or turn-off event, wherein the control signal (302) is based on the first curve (106a) configured to provide a gradual increase in light intensity output by the light emitting diode (200) after the turn-on event or the second curve (106b) configured to provide a gradual decrease in light intensity output by the light emitting diode (200) after the turn-off event.

12. The lighting device of claim 11 comprising a plurality of light emitting diodes (200), wherein the controller (100) is configured to provide the control signal (102) to each of the plurality of the light emitting diodes (200).

13. The lighting device) of claim 11 further comprising: a set of pulse width modulation data (110) stored in a look-up table (104) from which the pulse width modulation data (110) defining the first curve (106a) and the second curve (106b) can be selected.

14. The lighting device of claim 11 further comprising: a driver (300) coupled to the controller (100), the driver (300) configured to provide the indication (302) of the turn-on event or the turn-off event to the controller (100).