Low power light emitting diode (LED) driver

Abstract

According to certain embodiments, an emergency lighting / electronic device comprises: a first driver configured to receive AC power from a power outlet and provide a variable level of DC power; a second driver configured to receive AC power from a backup power source and provide a constant level of DC power; LED lights configured to provide light having a brightness based in a received level of DC power; and a switch configured to connect one of the first driver or the second driver to the LED lights based on whether the power outlet provides AC power.

Description

[0001] LOW POWER LIGHT EMITTING DIODE (LED) DRIVER

[0002] BACKGROUND

[0003] 1. FIELD

[0004] This disclosure relates to emergency lighting. More particularly, the disclosure relates to a low power Light Emitting Diode (LED) driver in a centralized emergency lighting system.

[0005] 2. DESCRIPTION OF RELATED ART

[0006] Emergency lighting can be activated during a power failure. This allows occupants to leave the dwelling. However, during the emergency, it is important that power from a backup source be provided to the lighting without the conditions that are applicable to the power from the power outlet. Accordingly, it would be desirable to ensure that the power from the backup source is provided to the lighting.

[0007] SUMMARY

[0008] According to certain embodiments, an emergency lighting / electronic device comprises: a first driver configured to receive AC power from a power outlet and provide a variable level of DC power; a second driver configured to receive AC power from a backup power source and provide a constant level of DC power; LED lights configured to provide light having a brightness based in a received level of DC power; and a switch configured to connect one of the first driver or the second driver to the LED lights based on whether the power outlet provides AC power.

[0009] According to certain embodiments, a method comprises: determining (620) whether a power outlet provides AC power; when the power outlet provides AC power, connect a first driver to LED lights; and when the power outlet does not provide AC power, connect a second driver to the LED lights.

[0010] BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0012] A brief description of each drawing is provided to better understand the drawings cited herein.

[0013] Referring now to FIG. 1, there is illustrated a block diagram of an emergency lighting / electronic device in accordance with an embodiment of the disclosure;

[0014] Referring now to FIG. 2, there is illustrated a block diagram of a first driver 105 in accordance with an embodiment of the disclosure;

[0015] Referring now to FIG. 3, there is illustrated a block diagram of a second driver 120 in accordance with an embodiment of the disclosure;

[0016] Referring now to FIG. 4, there is illustrated a block diagram of a switch in accordance with an embodiment of the disclosure;

[0017] Referring now to FIG. 5, there is illustrated a flow diagram of a method in accordance with an embodiment of the disclosure; and

[0018] Referring now to FIG. 6, there is illustrated a flow diagram of a method in accordance with an embodiment of the disclosure.

[0019] DETAILED DESCRIPTION

[0020] It should be appreciated that various embodiments of the present disclosure and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for a corresponding embodiment. With regard to the description of the drawings, similar reference numerals may be used to refer to similar or related elements. It is to be understood that a singular form of a noun corresponding to an item may include at least one of the things, unless the relevant context clearly indicates otherwise. As used herein, each of such phrases as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C," may include any one of, or all possible combinations of the items enumerated together in a corresponding one of the phrases. As used herein, such terms as "1st" and "2nd," or "first" and "second" may be used to simply distinguish a corresponding component from another, and does not limit the components in other aspect (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term "operatively" or "communicatively", as "coupled with," "coupled to," "connected with," or "connected to" another element (e.g., a second element), it means that the element may be coupled with the other element directly (e.g., wired connection), wirelessly, or via a third element. Additionally, an action that is based on a condition shall not be understood to be directly based on detection of the condition, but may be based on detection of circumstances that are indicative of the condition.

[0021] As used herein, the term "module" may include a unit implemented in hardware, software, or firmware, and may interchangeably be used with other terms, for example, "logic," "logic block," "part," or "circuitry". A module may be a single integral component, or a minimum unit or part thereof, adapted to perform at least one functions. For example, according to an embodiment, the module may be implemented in a form of an application-specific integrated circuit (ASIC).

[0022] According to an embodiment, methods according to the various disclosed embodiments of the disclosure may be provided by being included in a computer program product. The computer program product may be traded as a commodity between a seller and a purchaser. The computer program product may be distributed in the form of a machine- readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed online (e.g., download or upload) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). When distributed online, at least part of the computer program product (e.g., a downloadable app) may be temporarily generated or at least temporarily stored in a machine-readable storage medium, such as a memory of a manufacturer's server, a server of the application store, or a relay server.

[0023] An LED lighting system can include LED lights. The LED lights can be configured to convert direct current (DC) electrical power into photons, thereby providing lighting. The DC power can include voltage and current within specified ranges. A power outlet can provide alternating current (AC) power to the LED lighting. Since the LED lights may convert DC power, the LED lighting system includes a driver. The driver can receive the AC power from the power outlet. The driver can convert the AC power to a DC power, regulate the current and voltage of the DC power, provide over-current and over-voltage protection, and output the DC power. Additionally, the driver can effectuate various lighting controls by varying the level of the DC power.

[0024] The lighting system may also include a variety of lighting controls to allow for selective and controlled lighting. The controls can include, for example, smart sensors, occupancy sensors, and daylight sensors, to name a few, to turn on / off and / or control the level of lighting. For purposes of this document, the term “level of lighting” shall be understood to also include binary levels, such as on and off. Moreover, 0 or “off’ can be is considered a “level of lighting.” A smart sensor allows a user to remotely control the LED lights or set a scheduled for the level of lighting. A motion sensor can automatically control the level of light based on the number of persons in proximity to the lights. A daylight sensor can control the level of lighting based on time of day or detected daylight. The foregoing lighting controls control the level of lighting, by controlling the level of DC power output by the driver.

[0025] Additionally, wall panel can either interrupt or reduce the AC power to the driver, thereby interrupting or reducing the variable level of DC power to the LED lights.

[0026] Additionally, regulations require emergency lighting in the event of power failure. For example, the National Fire Protection Association (NFPA) publishes safety standards including the NFPA 101 Life Safety Code™ (LSC). The LFC is a safety code that outlines key requirements for emergency lighting. The regulations commonly require that during a power failure, the LED lights receive power from a backup power source. In a centralized backup system, the backup power source can include a battery and an inverter, or a generator. In the case of a battery and inverter, the battery provides a DC power and the inverter converts the DC power to an AC power similar to the AC power provided by the power outlet. In the case of a generator, the generator provides the AC power. A driver can similarly convert the AC power from the backup power source to provide DC power to the LED lights during a power outage. However, as per regulations, the lighting from power originating from the backup power source should not be subject to the same lighting controls as the lighting from power originating from the power outlet. During a power outage or emergency, the level of lighting should remain at constant level sufficient to facilitate egress, regardless of the position of the wall mounted switches and dimmers, the preset schedule, occupancy, and daylight. For example, a user should not be able to turn off or dim the lights during a power outage.

[0027] An emergency light control device transfer switch (emergency transfer switch) can negate or override the lighting controls for the power originating from the power outlet and provide full power to the LED lights. However, the emergency transfer switch can be complicated, utilize expensive components, and have a large physical size. Certain embodiments of this disclosure can provide power from the backup power source that is not subject to the lighting controls for the power originating from the power outlet. Certain embodiments can include an additional driver for the power from the backup power source and a switch that selects either one of the driver for the power from the power outlet and the driver for the power from the backup power source. Referring now to FIG. 1, there is illustrated a block diagram of an emergency lighting / electronic device 100 in accordance with an embodiment of the disclosure. The emergency lighting device 100 can comprise a lighting system that includes a housing 101, contained within the housing electronic components, including a first driver 105, a sensing circuit 110, a lighting control module 115, a second driver 120, a switch 125, and LED lights 130, and a wall panel 135 are coupled to the housing electronic components.

[0028] The LED lights 130 can operate on DC power supplied by the first driver 105. The LED lights 130 can be configured to provide lighting having a brightness based on a level of DC power provided to the LED lights 130. For example, a higher level of DC power can result in higher brightness, up to a maximum level. The first driver 105 receives AC power from a power outlet, such as a normal AC mains 106, via lighting control module 115. The normal AC mains can include, for example, AC electric power from an electrical grid. In certain embodiments, the normal AC mains 106 can comprise, for example 120 V at 60 Hz (common to North America), 230 V at 50 Hz, or 230 V at 60 Hz, to name a few. The first driver 105 provides a variable level of DC power that is within a predetermined range of power levels to the LED lights 130. The predetermined range can be none (off) to the power level that causes the LED lights 130 to provide light with maximum brightness.

[0029] The lighting control module 115 can include a variety of lighting controls to allow for selective lighting. The controls can include dimmers, smart sensors, motion sensors, and daylight sensors to control the level of lighting. The lighting control module 115 can control the variable level of DC power provided by the first driver 105 by outputting a signal to the first driver 105. The signal indicates a power level within the predetermined range of power levels. The first driver 105 can output the variable level of DC power to the LED lights 130, based on the signal from the lighting control module 115. Additionally, the first driver 105 regulates the current and voltage that is output, as well as providing surge protection. In response to receiving the variable level of DC power the LED lights 130 radiate light.

[0030] Additionally, the wall panel 135 can either interrupt or reduce the AC power from the normal AC mains 106 to the first driver 105, thereby causing the first driver 105 to either interrupt or reduce the variable level of DC power to the LED lights 130. The wall panel 135 can include an on / off switch and an analog control switch. The on / off switch selectively interrupts AC power from the normal AC mains to the first driver 105 when it is in the “off’ position. The analog control switch selectively reduces the AC power from the normal AC mains 106. During a power failure, the LED lights 130 can receive power from a backup power source, such as emergency AC mains 107. In a centralized backup system, the emergency AC mains 107 can include a battery and an inverter, or a generator. The second driver 120 can convert the emergency AC mains 107 to provide controlled DC power to the LED lights 130 during a power outage.

[0031] However, as per regulations, the power originating from the emergency AC mains 107 source may not be restricted by the lighting control module 115. During a power outage or emergency, the level of lighting can remain at constant level sufficient to facilitate egress, regardless of the various light controls provided by the lighting control module 115.

[0032] Accordingly, a switch 125 can be configured to select the first driver 105 or the second driver 120. The switch 125 can be configured to select the first driver 105 when the normal AC mains 106 provides power. When the normal AC mains 106 does not provide power, the switch can select the second driver 120.

[0033] The second driver 120 can provide a constant level of DC power. In contrast to the first driver 105, the wall panel 135 may not control the AC power that is provided to the second driver 120, and the lighting control module 115 may not control the level of DC power output by the second driver 120. As a result, the second driver 120 can provide a constant level of DC power.

[0034] The switch 125 can select one of the first driver 105 and the second driver 120 based on a signal that is provided by the sensing circuit 110. The sensing circuit 110 can detect a power outage condition by determining whether the normal AC mains 106 supplies AC power, and provides an output indicating whether the normal AC mains 106 supplies the AC power. In certain embodiments, the sensing circuit 110 can provide a logical signal such as a “1” indicating that power is present, and “0” indicating that there is no power, or vice versa. For example, using a flyback topology or converter.

[0035] Referring now to FIG. 2, there is illustrated a block diagram of a lighting control module 115 in accordance with an embodiment of the disclosure. The lighting control module 115 may include an occupancy sensor 205, a smart sensor 207, a daylight sensor 210, a controller 215, and an output 220. Certain embodiments may include different sensors, or may omit some of the foregoing sensors.

[0036] The occupancy sensor 205 can include a motion detector that can generate an infrared signal that detects the number of occupants that are proximate to the light system. In certain embodiments, when the occupancy sensor detects one or more persons that are in proximity, the occupancy sensor 205 provides a logical 1 to the controller 215. When the occupancy sensor does not detect one or more persons in proximity, the occupancy sensor 205 can provide a logical “0” to the controller 215. Certain embodiments may include an occupancy sensor 205 that provides the number.

[0037] The smart sensor 207 can comprise a transceiver that is configured to receive signals from an external electronic device, such as, for example, a smartphone, a cellular network, a computer, or a server. In certain embodiments, the smart sensor 207 can comprise a short-range receiver, such as a Bluetooth or Wi-Fi Direct (Wi-Fi P2P) transceiver, or a transceiver configured to communication with a cellular network. The smart sensor 207 can be configured to receive scheduling signals from the external electronic device. For example, in certain embodiments, the smart sensor 207 may transmit an interface for facilitating selection of a lighting schedule or a virtual switch allowing the user to remotely set the level of lighting. The smart sensor 207 can provide the controller 215 with a schedule and or remote setting from a user.

[0038] A daylight sensor 210 can comprise a photodiode configured to determine a level of ambient light in the vicinity of the LED lights 130. The daylight sensor 210 can provide a signal indicating the level of ambient light to the controller 215.

[0039] The controller 215 is configured to receive input from the occupancy sensor 205, smart sensor 207, and daylight sensor 210. Additionally, the controller 215 may be equipped with a clock that provides time of day and a timer. Based on the inputs received by the occupancy sensor 205, smart sensor 207, and the daylight sensor 210, the controller 215 may provide an output 220 indicating a variable level of DC power to the first driver 105.

[0040] Referring now to FIG. 3, there is illustrated a block diagram of a first driver 105 in accordance with an embodiment of the disclosure. The first driver 105 can include a rectifier 305, a power regulator 310, and output 320. The rectifier 305 receives power from the normal AC mains 106 and converts the power to a variable level of DC power. The power regulator 310 regulates the current and voltage of the variable level of DC power. The output 320 provides the variable level of DC power to the switch 125.

[0041] The controller 315 receives the output from the lighting control module 115. Based on the output from the lighting control module 115, the controller 215 can control the variable level of DC power that is output by the rectifier 305. Additionally, the wall panel 135 can control the amount of AC power that is provided from the normal AC mains 106 to the rectifier 305.

[0042] Referring now to FIG. 4, there is illustrated a block diagram of a second driver

[0043] 120 in accordance with an embodiment of the disclosure. The second driver 120 can include a rectifier 405, regulator 410, and output 420. The second driver 120 can receive the emergency AC mains 107, via the rectifier 405. It is noted that during a power outage, the emergency AC mains 107 provides power. The rectifier 405 can convert the emergency AC mains 107 to a constant level of DC power. The power regulator 410 regulates the current and voltage of the constant level of DC power. The output 420 provides the constant level of DC power to the switch 125.

[0044] In certain embodiments, the second driver 120 is not subject to control by the lighting control module 115. Accordingly, the second driver 120 can provide a constant level of DC power that may not be controlled by the light control module.

[0045] In certain embodiments, the second driver 120 can be configured to output a lower level of DC power than the first driver 105 outputs.

[0046] Referring now to FIG. 5, there is illustrated a block diagram of a switch 125 in accordance with an embodiment of the disclosure. The switch 125 can comprise a relay 505 that is electrically connected to the first driver 105, second driver 120, and the LED lights 130. The relay 505 can selectively connect one of the first driver 105 and the second driver 120 to the LED lights 130.

[0047] The sensing circuit 110 controls the relay 505 by providing a signal indicating whether the normal AC mains 106 is providing power. When the sensing circuit 110 provides a signal indicating that the normal AC mains 106 is providing AC power, the relay 505 connects the first driver 105 to the LED lights 130. When the sensing circuit 110 provides a signal indicating the that the normal AC mains 106 is not providing AC power, the relay 505 connects the second driver 120 to the LED lights 130.

[0048] In certain embodiments, the relay 505 that connects one of two inputs to an output, based on receipt of a logical 0 or 1.

[0049] Referring now to FIG. 6, there is illustrated a flow diagram of a method in accordance with an embodiment of the disclosure. It is noted that the foregoing operations can occur in different orders, simultaneously, or any combination thereof. At 605, the switch 125 connects the first driver 105 to the LED lights 130. Since the normal AC mains 106 provides AC power, the sensing circuit 110 provides a signal indicating the same to the switch 125, causing the switch 125 to connect the first driver 105 to the LED lights 130.

[0050] At 610, the first driver 105 receives a signal from the lighting control module 115, indicating a variable level of DC power, causing the first driver 105 to provide the variable level of DC power at 615. At 620, the sensing circuit 110 determines whether the normal AC mains 106 is providing AC power. If the normal AC mains 106 is providing AC power at 620, the switch 125 continues to connect the first driver 105 to the LED lights and steps 605-620 are repeated.

[0051] When the normal AC mains 106 does not provide AC power at 620, such as during a power outage, the switch 125 connects the second driver 120 to the LED lights 130 at 625. At 630, the second driver 120 provides a constant level of DC power to the LED lights. The sensing circuit 110 detects whether the normal AC mains 106 provides AC power at 620, and based thereon, either operations 605-615 are repeated or 625 and 630 are repeated.

[0052] According to certain embodiments, an emergency lighting / electronic device (100) comprises: a first driver (105) configured to receive AC power from a power outlet (106) and provide a variable level of DC power; a second driver (120) configured to receive AC power from a backup power (107) source and provide a constant level of DC power; LED lights (130) configured to provide light having a brightness based in a received level of DC power; and a switch (125) configured to connect one of the first driver (105) or the second driver (120) to the LED lights (130).

[0053] According to certain embodiments, the emergency lighting / electronic device (100) further comprising: a lighting control module (115) configured to provide an output to the first driver (105), and wherein the variable level of DC power provided by the first driver (105) is based at least in part on the output.

[0054] According to certain embodiments, the first driver (105) comprises: a rectifier (305) configured to convert the AC power from the power outlet (106) to the variable level of DC power based at least in part on the output from the lighting control module (115).

[0055] According to certain embodiments, the second driver (120) comprises a rectifier, the rectifier configured to convert the AC power from the backup power (107) to the constant level of DC power.

[0056] According to certain embodiments, the lighting control module comprises at least one of an occupancy sensor (205), a smart sensor (207), and a daylight sensor (210).

[0057] According to certain embodiments, the variable level of DC power is within a range having a maximum power, and wherein the constant level of DC power is less than the maximum power.

[0058] According to certain embodiments, the emergency lighting / electronic device (100) comprises: a sensing circuit (110) configured to provide an output indicating whether the power outlet (106) provides AC power, and the one of the first driver (105) or the second driver (120) is based on the output from the sensing circuit (110). According to certain embodiments, the emergency lighting / electronic device (100) further comprising: a wall panel (135) configured to selectively interrupt or reduce a level of AC power provided from the power outlet (106) to the first driver (105).

[0059] According to certain embodiments, a method comprises: determining (620) whether a power outlet (106) provides AC power; when the power outlet (106) provides AC power, connect (605) a first driver (105) to LED lights (130); and when the power outlet (106) does not provide AC power, connect (625) a second driver (120) to the LED lights (130).

[0060] According to certain embodiments, the method further comprises: providing a variable level of power (615) to the LED lights (130) in response to connecting the first driver (105).

[0061] According to certain embodiments, the method further comprises: providing a constant level of DC power (630) to the LED lights (130) in response to connecting the second driver (120).

[0062] According to certain embodiments, the method further comprises receiving (610) a signal from a lighting control module (115), and the variable level of DC power is based on the signal from the lighting control module (115).

[0063] According to certain embodiments, a switch (125) connects the first driver (105) to LED lights (130), and the second driver (120) to the LED lights (130).

[0064] According to certain embodiments, the switch (125) comprises a relay.

[0065] While at least one embodiments of the disclosure have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein. For example, various elements may be omitted, added, revised, or substituted from the foregoing embodiments, without departing from the spirit and scope as defined by the following claims.

Claims

CLAIMS:

1. An emergency lighting c device (100) comprising: a housing (101), wherein the housing contains, a first driver (105) configured to receive mains AC power and provide a variable level of DC power; a second low power driver (120) configured to receive AC power from a backup power source (107) and provide a constant level of DC power; a sensing circuit (110) configured to provide an output indicating whether the power outlet (106) provides AC power to the first driver (105), a switch (125) configured to connect one of the first driver (105) or the second low power driver (120) to the LED lights (130) based on the output of the sensing circuit (110), andLED lights (130) coupled to the switch (125) and configured to provide light having a brightness based on a received level of DC power.

2. The emergency lighting device (100) of claim 1, further comprising: a lighting control module (115) configured to provide an output to the first driver (105), and wherein the variable level of DC power provided by the first driver (105) is based at least in part on the output.

3. The emergency lighting device (100) of claim 2, wherein the first driver (105) comprises: a rectifier (305) configured to convert the AC power from the power outlet (106) to the variable level of DC power based at least in part on the output from the lighting control module (115).

4. The emergency lighting device (100) of claim 3, wherein the second driver (120) comprises a rectifier, the rectifier configured to convert the AC power from the backup power source (107) to the constant level of DC power.

5. The emergency lighting device (100) of claim 2, wherein the lighting control module comprises at least one of an occupancy sensor (205), a smart sensor (207), and a daylight sensor (210).

6. The emergency lighting device (100) of claim 1, wherein the variable level of DC power is within a range having a maximum power, and wherein the constant level of DC power is less than the maximum power.

7. The emergency lighting device (100) of claim 1, further comprising: a wall panel (135) configured to selectively interrupt or reduce a level of AC power provided from the power outlet (106) to the first driver (105).

8. The emergency lighting device (100) of claim 1, wherein the switch (125) comprises a relay (505).

9. A method of providing emergency lighting, the method comprising: providing mains AC power to first driver to provide a variable level of DC power to LED lights or backup AC power to a second low power driver (120) to provide a constant level of DC power to the LED lights; sensing weather mains AC power is provided to the first driver (105) and providing an output indicator; connecting one of the first driver (105) or the second low power driver (120) to the LED lights (130) based on the output indicator, and providing a brightness light level of the LED lights based on a received level of DC power.

10. The method of claim 9, further comprising: receiving (610) a signal from a lighting control module (115), and wherein the variable level of DC power is based on the signal from the lighting control module (115).

11. The method of claim 9, wherein a switch (125) connects the first driver (105) to the LED lights (130), and the second driver (120) to the LED lights (130).

12. The method of claim 11, wherein the switch (125) comprises a relay.

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