Patent Application
20240373523
Embodiments described herein relate to a lighting control system having a driver for controlling multiple light sources.
Light emitting diode (LED) drivers send a single drive level to an LED string (or parallel connections of LED strings). Analog control may be used to simulate incandescent bulb color shift with LED arrays. For example, the voltage and/or current drive to the LED array may be varied. However, existing techniques perform poorly due to jumps in color temperature and/or inconsistent color temperature shift throughout the dimming range when using this analog control.
Embodiments described herein provide for a single LED driver that controls multiple LED strings on a single wire. For example, the LED driver switches an output drive between two preset levels to send separate control to two LED strings on a single wire and connected in parallel. The LED driver may be able to “swing” between two preset reference voltages to send two discrete output levels. Alternatively, the LED driver generates an output signal based on a mixture of the preset reference voltages. This differs from traditional LED drivers that use only a single reference voltage. The LED driver may operate in conjunction with a multiplexer, a controller, or other suitable electrical device.
One example provides a lighting control system comprising an input node, a first light source connected to the input node and configured to generate a first light, and a second light source connected to the input node and configured to generate a second light. The lighting control system also includes a driver circuit connected to the input node. The driver circuit is configured to receive a first signal indicating a driving state of the lighting control system, receive a second signal indicating a magnitude value of an output signal, and generate the output signal based on the first signal and the second signal. The driver circuit is configured to provide the output signal to the input node to control the first light source and the second light source.
Another example provides a method for controlling a plurality of light sources including a first light source connected to an input node and a second light source connected to the input node. The method includes receiving, with a driver circuit, a first signal indicating a driving state of the driver circuit, and receiving, with the driver circuit, a second signal indicating a magnitude value of an output signal. The method includes generating, with the driver circuit, the output signal based on the first signal and the second signal, and providing, with the driver circuit, the output signal to the input node to control the first light source and the second light source.
Another example provides a lighting control system comprising an input node, a first light source connected to the input node and configured to generate a first colored light, and a second light source connected to the input node and configured to generate a second colored light. The lighting control system also includes a multiplexer configured to generate a first signal based on a driving state of the lighting control system and a driver circuit connected to the multiplexer and to the input node. The driver circuit is configured to receive, from the multiplexer, the first signal, receive a second signal indicating a magnitude value of an output signal, and generate the output signal based on the first signal and the second signal. The driver circuit is configured to provide the output signal to the input node to control the first light source and the second light source.
Before any implementations of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other implementations and of being practice or of being carried out in various ways.
Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “mounted,” “connected,” and “coupled” are used broadly and encompass both direct and indirect mounting, connecting, and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and can include electrical connections or couplings, whether direct or indirect. Also, electronic communications and notifications may be performed using other known means including direct connections, wireless connections, etc.
It should also be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components, may be utilized to implement the disclosure. Furthermore, and as described in subsequent paragraphs, the specific configurations illustrated in the drawings are intended to exemplify implementations of the disclosure. Alternative configurations are possible.
Other aspects of the embodiments will become apparent by consideration of the detailed description and accompanying drawings.
One or more examples, embodiments, aspects, and features are described and illustrated in the following description and accompanying drawings. These examples are not limited to the specific details provided herein and may be modified in various ways. Other examples and embodiments may exist that are not described herein. For instance, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not listed. Some examples described herein may include one or more electronic processors configured to perform the described functionality by executing instructions stored in non-transitory, computer-readable medium. Similarly, embodiments described herein may be implemented as non-transitory, computer-readable medium storing instructions executable by one or more electronic processors to perform the described functionality. As used in the present application, “non-transitory computer-readable medium” comprises all computer-readable media but does not include a transitory, propagating signal. Accordingly, non-transitory computer-readable medium may include, for example, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, ROM (Read Only Memory), RAM (Random Access Memory), register memory, a processor cache, other memory and storage devices, or combinations thereof.
The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. For example, the use of “including,” “containing,” “comprising,” “having,” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “connected” and “coupled” are used broadly and encompass both direct and indirect connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings and can include electrical connections or couplings, whether direct or indirect. In addition, electronic communications and notifications may be performed using wired connections, wireless connections, or a combination thereof and may be transmitted directly or through one or more intermediary devices over various types of networks, communication channels, and connections. Relational terms, for example, first and second, top and bottom, and the like may be used herein solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Embodiments or portions of an embodiment can be combined with other embodiments or portions of other embodiments to create yet further embodiments, whether or not they are specifically illustrated or described.
Unless the context of their usage unambiguously indicates otherwise, the articles “a,” “an,” and “the” should not be interpreted as meaning “one” or “only one.” Rather these articles should be interpreted as meaning “at least one” or “one or more.” Likewise, when the terms “the” or “said” are used to refer to a noun previously introduced by the indefinite article “a” or “an,” “the” and “said” mean “at least one” or “one or more” unless the usage unambiguously indicates otherwise.
It should also be understood that although certain drawings illustrate hardware and software located within particular devices, these depictions are for illustrative purposes only. In some embodiments, the illustrated components may be combined or divided into separate software, firmware and/or hardware. For example, instead of being located within and performed by a single electronic processor, logic and processing may be distributed among multiple electronic processors. Regardless of how they are combined or divided, hardware and software components may be located on the same computing device or may be distributed among different computing devices connected by one or more networks or other suitable communication links.
Thus, in the claims, if an apparatus or system is claimed, for example, as including an electronic processor or other element configured in a certain manner, for example, to make multiple determinations, the claim or claim element should be interpreted as meaning one or more electronic processors (or other element) where any one of the one or more electronic processors (or other element) is configured as claimed, for example, to make some or all of the multiple determinations. To reiterate, those electronic processors and processing may be distributed.
The multiplexer 102 is connected (e.g., electrically connected and/or communicatively connected) to the driver circuit 104. The multiplexer 102 provides a reference voltage to the driver circuit 104. The multiplexer 102 may receive, among other things, a first voltage control level 110 (for example, voltage level A, a first reference voltage), a second voltage control level 112 (for example, voltage level B, a second reference voltage), and an A/B ratio signal 114. In some instances, the first voltage control level 110 and the second voltage control level 112 are constant voltage values provided to the multiplexer 102. In other instances, the first voltage control level 110 and the second voltage control level 112 may vary over time. The values of the first voltage control level 110 and the second voltage control level 112 may be selected based on the desired implementation of the first light source 106 and the second light source 108.
The A/B ratio signal 114 is a control signal that controls a ratio of the first voltage control level 110 and the second voltage control level 112 selected by the multiplexer 102. In some implementations, the A/B ratio signal 114 is a binary signal that controls the multiplexer 102 to select either the first voltage control level 110 or the second voltage control level 112. The A/B ratio signal 114 may be a pulse width modulated (PWM) signal that varies between a “high” value (for example, “1”) and a “low” value (for example, “0”). In such an implementation, the A/B ratio signal 114 indicates either 0% voltage level A and 100% voltage level B, or 100% voltage level A and 0% voltage level B. Accordingly, the multiplexer 102 outputs either the first voltage control level 110 or the second voltage control level 112 to the driver circuit 104 as the reference voltage. The A/B ratio signal 114 may have a constant duty cycle, or the duty cycle may be modulated over time.
In other implementations, the A/B ratio signal 114 is an analog signal that indicates a ratio of the first voltage control level 110 and the second voltage control level 112. The A/B ratio signal 114 may be a PWM signal that is modulated between 0 and 100% depending on the desired mix of A and B. For example, the A/B ratio signal may indicate a ratio of 25% voltage level A and 75% voltage level B, 50% voltage level A and 50% voltage level B, 38% voltage level A and 62% voltage level B, or some other ratio of voltage level A and voltage level B. Accordingly, the reference voltage provided by the multiplexer 102 to the driver circuit 104 is the ratio of the first voltage control level 110 and the second voltage control level 112 indicated by the A/B ratio signal 114. Embodiments described herein may refer to the A/B ratio signal 114 as a signal that indicates a driving state of the lighting control system 100 or a driving state of the driver circuit 104.
The driver circuit 104 may be, for example a constant current (CC) driver, a constant voltage (CV) driver, an analog voltage driver, an analog current driver, or a combination thereof. The driver circuit 104 receives the reference voltage output by the multiplexer 102 and receives an intensity signal 116. The intensity signal 116 is a control signal that indicates the overall duty cycle of an output control signal output by the driver circuit 104. In some instances, the intensity signal 116 is a binary PWM signal that varies between a “high” value and a “low”. In other instances, the intensity signal 116 is a PWM signal that is modulated between 0 and 100% depending on the desired output luminance of the first light source 106 and the second light source 108. The intensity signal 116 may have a constant duty cycle, or the duty cycle may be modulated over time.
The driver circuit 104 generates an output control signal based on the reference voltage output by the multiplexer 102 and based on the intensity signal 116. Particularly, in some embodiments, the driver circuit 104 transmits two individually-controllable drive levels down a single pair of wires which can be used to mix two different LED strings (e.g., the first light source 106 and the second light source 108).
For example, from time x0 to time x1, the intensity signal 116 and the A/B ratio signal 114 each have a value of “1”. Accordingly, the output control signal has a current value of “A” and the driver circuit 104 is in the A state. From time x1 to x2, the intensity signal 116 has a value of “1” and the A/B ratio signal 114 has a value of “0”. Accordingly, the output control signal has a current value of “B” and the driver circuit 104 is in the B state. From time x2 to x3, the intensity signal 116 and the A/B ratio signal 114 both have a value of “0”, and the driver circuit 104 does not provide any output current.
In the example of
However, in other implementations, the intensity signal 116 and the A/B ratio signal 114 may be adjusted to values between 0 and 100%. In such implementations, mixtures of the A state and the B state of the driver circuit 104 are achieved to provide current to both the first light source 106 and the second light source 108 simultaneously.
The first voltage control level 110, the second voltage control level 112, the A/B ratio signal 114, and the intensity signal 116 may be received from an external device via a data connection (e.g., a wired connection via ethernet, a wireless connection, or the like). The external device may be, for example, a wall station, a lighting control console, an architectural control system, or the like.
Returning to
In some embodiments, the first light source 106 and the second light source 108 have different forward voltages. For example, the first light source 106 may have a first forward voltage (for example, 2.0 V) and the second light source 108 may have a second forward voltage greater than the first forward voltage (for example, 3.0 V). When the magnitude of the output control signal is greater than the first forward voltage but less than the second forward voltage (for example, 2.5 V), only the first light source 106 receives power. When the magnitude of the output control signal is greater than the second forward voltage (for example, 3.2 V), both the first light source 106 and the second light source 108 receive power. When the magnitude of the output control signal is less than the first forward voltage (for example, 1.8 V), neither the first light source 106 nor the second light source 108 receive power.
In the example of
Additionally, the first light source 106 and the second light source 108 may emit different colored light. For example, the first light source 106 may emit a white light, while the second light source 108 emits a single-color light (such as red, blue, green, and/or the like). Accordingly, embodiments described herein achieve different color temperatures with smooth transitions as the temperature changes. In some embodiments, the first light source 106 and the second light source 108 form a tunable white LED array, and implementation of the driver circuit 104 provides for smooth changes in temperature of the white LED array.
In some implementations, the operations of the multiplexer 102 are performed by a controller. For example,
The memory 306 includes, for example, read-only memory (ROM), random access memory (RAM) (for example, dynamic RAM [DRAM], synchronous DRAM [SDRAM], etc.), electronically erasable programmable read-only memory (EEPROM), flash memory, a hard disk, an SD card, other non-transitory computer-readable media, or a combination thereof. The electronic processor 304 is connected to the memory 306 and executes software instructions that are capable of being stored in a RAM of the memory 306 (for example, during execution), a ROM of the memory 306 (for example, on a generally permanent basis), or another non-transitory computer-readable medium such as another memory or a disc. Alternatively or in addition, the memory 306 is included in the electronic processor 304. Software included in some implementations of the lighting control system 300 can be stored in the memory of the controller 302. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. In other constructions, the controller 302 includes additional fewer, or different components. For example, the controller 302 may be comprised of only hardware components, such as switches and logical gates.
In the example of
In some instances, a switching device is provided to control the flow of current to the first light source 106 and the second light source 108. For example,
At block 505, the controller 302 receives a first reference voltage. For example, the controller 302 receives the first voltage control level 110. At block 510, the controller 302 receives a second reference voltage. For example, the controller 302 receives the second voltage control level 112. At block 515, the controller 302 receives a ratio signal indicating a ratio of the first reference voltage and the second reference voltage. For example, the controller 302 receives the A/B ratio signal 114.
At block 520, the controller 302 generates an output reference voltage based on the first reference voltage, the second reference voltage, and the ratio signal. At block 525, the controller 302 provides the output reference voltage to the driver circuit 104.
At block 605, the driver circuit 104 receives a first signal indicating a driving state of the lighting control system 100. For example, the driver circuit 104 receives the reference voltage from the multiplexer 102 or the controller 302. At block 610, the driver circuit 104 receives a second signal indicating a magnitude value of an output signal. For example, the driver circuit 104 receives the intensity signal 116.
At block 615, the driver circuit 104 generates the output signal based on the first signal and the second signal. For example, the driver circuit 104 generates the output control signal based on the reference voltage from the multiplexer 102 or the controller 302 and based on the intensity signal 116. At block 620, the driver circuit 104 provides the output signal to the input node 118 to control the first light source 106 and the second light source 108.
Lighting controls systems described herein may be implemented within multiple different types of luminaires. For example,
Additionally, in some implementations, multiple luminaire housings are connected in series to control elements. For example,
In some implementations, the driver circuit 104 is a multi-channel driver. For example,
Thus, embodiments described herein provide, among other things, a lighting control system having a driver for controlling multiple light sources. Various features and advantages are set forth in the following claims.
