U.S. patent application number 15/492430 was filed with the patent office on 2017-08-03 for led lamp failure alerting system.
The applicant listed for this patent is iLumisys, Inc.. Invention is credited to John Ivey, Dennis Siemiet.
Application Number | 20170223787 15/492430 |
Document ID | / |
Family ID | 41724302 |
Filed Date | 2017-08-03 |
United States Patent
Application |
20170223787 |
Kind Code |
A1 |
Siemiet; Dennis ; et
al. |
August 3, 2017 |
LED LAMP FAILURE ALERTING SYSTEM
Abstract
A lighting system includes at least one LED and at least one
regulator in communication with the at least one LED. The at least
one regulator is configured to supply a substantially constant
current to the at least one LED while allowing a light output from
the at least one LED to degrade over time towards a target minimum
light output, and once the light output of the at least one LED is
below the target minimum light output, increase current to the at
least one LED to maintain the light output at the target minimum
light output.
Inventors: |
Siemiet; Dennis; (Rochester
Hills, MI) ; Ivey; John; (Farmington Hills,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
iLumisys, Inc. |
Troy |
MI |
US |
|
|
Family ID: |
41724302 |
Appl. No.: |
15/492430 |
Filed: |
April 20, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14202443 |
Mar 10, 2014 |
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15492430 |
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12202662 |
Sep 2, 2008 |
8674626 |
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14202443 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05B 45/14 20200101;
H05B 45/20 20200101; G01J 2001/4252 20130101; G01J 1/32 20130101;
H05B 45/00 20200101; F21V 23/0457 20130101; H05B 45/10 20200101;
H05B 45/50 20200101; F21Y 2115/10 20160801; H05B 45/58 20200101;
F21K 9/232 20160801; F21K 9/278 20160801 |
International
Class: |
H05B 33/08 20060101
H05B033/08; F21K 9/278 20060101 F21K009/278 |
Claims
1. A system comprising: a first fluorescent tube replacement device
configured for use in a first conventional fluorescent tube
fixture, comprising: one or more first LEDs; and a first connector
configured to physically engage the first device with one or more
sockets of the first fluorescent tube fixture; a second fluorescent
tube replacement device configured for use in a second conventional
fluorescent tube fixture comprising: one or more second LEDs; and a
second connector configured to physically engage the second device
with one or more sockets of the second fluorescent tube fixture; at
least one photodetector configured to generate one or more first
signals indicating that a light output of the first device is below
a target minimum light output; and a regulator configured to
regulate currents in the first device and the second device in
response to the one or more first signals.
2. The system of claim 1, wherein the regulator is in communication
with the at least one photodetector for receiving the one or more
first signals.
3. The system of claim 1, further comprising: at least one thermal
sensor configured to generate one or more second signals indicating
an operating temperature of the one or more first LEDs, the
regulator in communication with the at least one thermal sensor for
receiving the one or more second signals, wherein the regulator is
further configured to regulate the current in the first device in
response to the one or more second signals.
4. The system of claim 3, wherein the regulator is further
configured to: determine that the operating temperature of the one
or more first LEDs exceeds a target temperature; and in response to
determining that the operating temperature of the one or more first
LEDs exceeds the target temperature, reduce current to the first
device until the operating temperature of the one or more first
LEDs drops below the target temperature.
5. The system of claim 1, further comprising: a low light output
indicator in communication with the at least one photodetector,
wherein the low light output indicator is configured to generate at
least one of a visual signal or an audio broadcast indicating that
the light output has been below the target minimum light output for
a predetermined period of time.
6. The system of claim 5, wherein the visual signal is generated
using one or more first LEDs.
7. The system of claim 5, wherein generating the visual signal
comprises generating light of a different color than light emitted
from the sone or more first LEDs.
8. The system of claim 1, wherein the one or more first LEDs
includes one or more supplemental LEDs on standby, and wherein
regulating current in the first device comprises supplying current
to the one or more supplemental LEDs, such that the one or more
supplemental LEDs contribute to maintaining the light output at the
target minimum light output.
9. A system comprising: a first fluorescent tube replacement device
configured for use in a first conventional fluorescent tube
fixture, comprising: at least one first LED; and a first connector
configured to physically engage the first device with one or more
sockets of the first fluorescent tube fixture; a second fluorescent
tube replacement device configured for use in a second conventional
fluorescent tube fixture, comprising: at least one second LED; and
a second connector configured to physically engage the second
device with one or more sockets of the second fluorescent tube
fixture; and a control system configured to manage the first device
and the second device, the control system configured to: detect a
light output of the first device, and regulate currents in the
first device and the second device in response to the detected
light output of the first device.
10. The system of claim 9, wherein the control system is further
configured to: sense an operating temperature of the at least one
first LED; determine that the operating temperature of the at least
one first LED exceeds a target temperature; in response to
determining that the operating temperature of the at least one
first LED exceeds the target temperature, reduce current in the
first device until the operating temperature of the at least one
first LED drops below the target temperature.
11. The system of claim 9, wherein the control system is further
configured to generate at least one of a visual signal or an audio
broadcast indicating that the light output has been below the
target minimum light output for a predetermined period of time, and
wherein generating the visual signal comprises turning on one or
more LEDs.
12. The system of claim 11, wherein the visual signal is generated
using the at least one first LED.
13. The system of claim 11, wherein generating the visual signal
comprises generating light of a different color than light emitted
from the at least one first LED.
14. The system of claim 9, wherein the at least one first LED
includes one or more supplemental LEDs on standby, and wherein
regulating current in the first device comprises powering the one
or more supplemental LEDs, such that the one or more supplemental
LEDs contribute to maintaining the light output at the target
minimum light output.
15. A system comprising: a first fluorescent tube replacement
device configured for use in a first conventional fluorescent tube
fixture, comprising: at least one first LED; a first light
transmitting cover at least partially enclosing the at least one
first LED, the first light transmitting cover at least partially
forming a first housing for the first device; and a first connector
attached to the first housing and configured to physically engage
the first device with one or more sockets of the first fluorescent
tube fixture; a second fluorescent tube replacement device
configured for use in a second conventional fluorescent tube
fixture, comprising: at least one second LED; a second light
transmitting cover at least partially enclosing the at least one
second LED, the second light transmitting cover at least partially
forming a second housing for the second device; and a second
connector attached to the second housing and configured to
physically engage the second device with one or more sockets of the
second fluorescent tube fixture; and a control system configured to
manage the first device and the second device, the control system
configured to: detect a light output of the first device, and
regulate currents in the first device and the second device in
response to the detected light output of the first device.
16. The system of claim 15, wherein the control system is further
configured to generate at least one of a visual signal or an audio
broadcast indicating that the light output has been below the
target minimum light output for a predetermined period of time.
17. The system of claim 15, wherein the at least one first LED
includes one or more supplemental LEDs on standby, and wherein
regulating current in the first device comprises powering the one
or more supplemental LEDs only upon the generation of the visual
signal or the audio broadcast, such that the one or more
supplemental LEDs contribute to maintaining the light output at the
target minimum light output.
18. The system of claim 1, wherein the first device comprises at
least two LEDs, and wherein at least one photodetector is disposed
between two of the LEDs.
19. A system comprising: a first fluorescent tube replacement
device for use in a first conventional fluorescent tube fixture,
comprising: a first housing; a first plurality of LEDs disposed
within the first housing; and one or more first connectors coupled
to the first housing, wherein the first connectors are configured
to physically engage the first device with one or more sockets of
the first fluorescent tube fixture; a second fluorescent tube
replacement device for use in a second conventional fluorescent
tube fixture, comprising: a second housing; a second plurality of
LEDs disposed within the second housing; and one or more second
connectors coupled to the second housing, wherein the second
connectors are configured to physically engage the second device
with one or more sockets of the second fluorescent tube fixture; a
photodetector configured to measure the light output from the first
device; and a regulator in electrical communication with the first
device and the second device, wherein the regulator is configured
to regulate currents in the first device and the second device in
response to the measured light output.
20. The system of claim 19, wherein the photodetector is disposed
between at least two LEDs of the first plurality of LEDs.
21. The system of claim 19, further comprising an indicator
disposed on the first housing and visible from an exterior of the
first housing, wherein the indicator is configured to provide a
visual signal when the regulator is unable to maintain the light
output above the threshold amount, and wherein the indicator is
disposed between at least two LEDs of the first plurality of
LEDs.
22. The system of claim 21, wherein the first plurality of LEDs and
the indicator are directed towards a front of the first
housing.
23. The system of claim 1, wherein the regulator is further
configured to: supply a substantially constant current to the first
device while allowing the light output from the first device to
degrade over time towards the target minimum light output without
varying the substantially constant current in response to the
degradation, and once the light output of the first device is below
the target minimum light output, increase current to the first
device to maintain the light output at the target minimum light
output.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 14/202,443 filed Mar. 10, 2014, which is a continuation of
U.S. patent application Ser. No. 12/202,662 filed Sep. 2, 2008, now
U.S. Pat. No. 8,674,626, issued on Mar. 18, 2014, the disclosure of
which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates in general to light fixtures
utilizing light emitting diodes, and more particularly, to failure
alerting systems for the light emitting diodes.
BACKGROUND
[0003] Light emitting diode (LED) lighting fixtures are useful for
a variety of applications. Examples of these applications include
commercial and household interior lighting, exterior and egress
lighting, emergency lighting, automotive lighting and instrument
lighting. LED lighting fixtures promise to provide improvements
over existing lighting technologies. One significant improvement is
a longer operating life. This improvement, however, raises
different challenges than other lighting technology. Whereas other
sources of light, such as fluorescent and incandescent, have a
failure mode of relatively sudden and complete shut-off, LEDs
typically continue to fade over time without shutting off
completely. This tendency has been recognized by the solid-state
lighting industry in the form of lifetime measurement criteria that
defines LED life as "L70", the hours of service at which the LED
will output 70% of its original and/or rated output at the
original/rated power draw.
[0004] This failure mode can be perceived as a benefit, for example
in the case of an LED lamp used to light an entrance over a dark
set of stairs. An incandescent light will fail immediately when the
filament burns out, leaving the entrance and stairs in the dark,
while an LED lamp will typically continue to provide light at some
level for a much longer period of time. However, the gradual
dimming can be problematic. For example, at a given power draw,
less light is output, resulting in an area that is less lit than
intended. This can result in safety or security problems. More
lights must be turned on or the lamps must be "undimmed" in order
for the light levels to reach the level desired. The result is
increased power consumption. Egress lighting requirements may
require lighting designers to over-specify the amount of light in
an area to ensure the required emergency egress light level is
available in emergency evacuations over the lifetime of a building.
This can cause regulatory barriers to the acceptance and
implementation of LEDs into commercial and institutional buildings.
In addition, due to the difficulty, time and expense of accurately
determining when an LED light has permanently dropped below the
acceptable light output limit, consumers may automatically replace
LEDs upon expiration of the warranty. This may result in years of
useful operational life being unnecessarily wasted, reducing the
cost effectiveness of using LED lighting in the first place.
BRIEF SUMMARY
[0005] Disclosed herein are embodiments of LED-based lights and
lighting systems. On such illustrative embodiment of lighting
system comprises at least one LED and at least one regulator in
communication with the at least one LED. The at least one regulator
is configured to supply a substantially constant current to the at
least one LED while allowing a light output from the at least one
LED to degrade over time towards a target minimum light output, and
once the light output of the at least one LED is below the target
minimum light output, increase current to the at least one LED to
maintain the light output at the target minimum light output.
[0006] Another embodiment disclosed herein is an LED-based light
comprising at least one LED, a connector connectable to a light
fixture, and a system for managing the at least one LED. The system
is configured to detect a light output of the at least one LED,
operate the at least one LED at a first power draw while allowing
the light output from the at least one LED to degrade over time
towards a target minimum light output, and once the light output of
the at least one LED is below the target minimum light output,
operate the at least one LED at an increased power draw to maintain
the light output at the target minimum light output.
[0007] Yet another embodiment is an LED-based light comprising at
least one LED, a lens at least partially enclosing the at least one
LED, the lens at least partially forming a housing for the
LED-based light, a connector attached to the housing and
configuring the LED-based light for connection to a light fixture,
and a system for managing the at least one LED. The system is
configured to detect a light output of the at least one LED,
operate the at least one LED to maintain the light output at a
target minimum light output, and generate one or more signals
indicating that the light output is low once the light output can
no longer be maintained at the target minimum light output.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The description herein makes reference to the accompanying
drawings wherein like reference numerals refer to like parts
throughout the several views, and wherein:
[0009] FIG. 1 is a perspective view of an embodiment of an LED lamp
with failure alerting system disclosed herein;
[0010] FIG. 2 is a schematic view of another embodiment of an LED
lamp with failure alerting system disclosed herein;
[0011] FIG. 3 is a perspective view of yet another embodiment of an
LED lamp with failure alerting system disclosed herein;
[0012] FIG. 4 is a schematic view of an embodiment of a failure
alerting system for use with an LED lamp as disclosed herein;
and
[0013] FIG. 5 is a schematic view of another embodiment of a
failure alerting system for use with an LED lamp as disclosed
herein.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0014] FIG. 1 illustrates one embodiment of an LED lamp 10 with a
failure alerting system. The lamp 10 comprises an LED lighting unit
12 comprising at least one LED 14, a photodetector 16, a regulator
18, a thermal sensor 20, and a low light output indicator 22.
[0015] In this illustrative embodiment, the photodetector 16 is
configured to detect an actual light output from at least one LED
14. The regulator 18 receives a signal from the photodetector 16
when the actual light output is below a target light output. When
the signal is received, the regulator 18 increases a current to the
one or more LEDs to maintain the target light output. The thermal
sensor 20 senses an operating temperature of the at least one LED
and controls the regulator 18 to increase the current and the
target light output to ensure the operating temperature does not
exceed a target temperature. In other words, the regulator 18
receives a thermal signal from the thermal sensor 20 and maintains
the current and the target light output such that the operating
temperature does not exceed a target temperature. The low light
output indicator 22 receives a signal from the photodetector 16
when the actual light output remains below the target light output
and produces a low light output signal.
[0016] The at least one LED 14 of the LED lamp 10 can be mounted on
a circuit board 24. The circuit board 24 may be made in one piece
or in sections joined by electrical bridge connectors. An
insulative board is typical, but other circuit board types, e.g.,
metal core circuit boards, can alternatively be used. Although the
circuit board 24 shown in FIG. 1 is a circular surface, the circuit
board 24 may be any shape desired or required depending on the
overall shape and design of the lamp 10.
[0017] The LEDs 14 can be mounted at predetermined intervals along
or around the circuit board 24 to uniformly emit light from the
lamp 10. The spacing between LEDs 14 along the circuit board 24 is
a function of the surface area of the circuit board 24, the amount
of light desired, the wattage of the LEDs 14, and the viewing angle
of the LEDs 14. More than one LED is commonly referred to as a bank
or array of LEDs. Within the scope of these embodiments, one or
more banks or arrays of LEDs can be mounted on one or more circuit
boards. The LEDs can emit white light and, thus, are commonly
referred to in the art as white LEDs. However, other types of LEDs
can be utilized, for example, red and green LEDs.
[0018] The LEDs 14 utilized in the lamp 10 are those known in the
art. The LEDs 14 can be, for example, surface-mounted LEDs, organic
LEDs, or high-power surface-mount devices of a type available from
Nichia. The LEDs 14 may have power ratings of 0.1 watts or more, or
more specifically, power ratings of one watt or more. However, the
power ratings are provided as examples and are not meant to be
limiting. Other power ratings can be used as desired or
required.
[0019] The lamp 10 also has a housing 26 consisting of a cover 28
and a base 30. It is contemplated that the housing 26 may be of any
suitable shape required or desired for use with light fixtures. As
a non-limiting example, the housing 26 may be a shroud open along
its length. The housing 26 may have as many ends as necessary for a
secure fit and the proper electrical connection.
[0020] The cover 28 may be made of any material known in the art to
be used in the lighting industry, including but not limited to UV
resistant plastic or glass. For example, the cover 28 can be made
from polycarbonate, acrylic, glass or another light transmitting
material. That is, the cover 28 can be transparent or translucent.
A translucent cover 28 can be made from a composite, such as
polycarbonate with particles of a light refracting material
interspersed in the polycarbonate.
[0021] The LEDs 14 can be arranged on the circuit board 24 or
another surface within the housing 26 to emit or shine through only
one side of the cover 28, thus directing the light to a
predetermined point of use, or arranged to emit light through more
than one side of the cover 28.
[0022] The photodetector 16 of the LED lamp 10 with failure
alerting system is shown in FIG. 1 located within the housing 26
and mounted on the circuit board 24. The photodetector 16 is
located to provide an accurate indication of the actual light
output of the at least one LED 14. The actual light output is
typically measured in lux. The photodetector 16 can be, for
example, a photo diode, a photo transistor, a photo cell or other
device capable of outputting a signal with respect to the light
level sensed.
[0023] The photodetector 16 is configured to detect the actual
light output from at least one LED 14 and send a signal to the
regulator 18 when the actual light output is below a target light
output. For example, the photodetector 16 can send a signal when
the LED provides lux implying less than 30 lumens, the target light
output. The photodetector 16 can be a single detector detecting the
actual light output of a single LED, a single detector detecting
the actual light output of multiple LEDs, and more than one
detector each detecting the actual light output from a different
LED. The configurations are provided by way of example and not
limitation and other configurations known to those skilled in the
art may be used.
[0024] In FIG. 1, the photodetector 16 is located within the
housing 26 on the circuit board 24. Alternatively, the
photodetector 16 can be located external to the LED lamp 10, as
shown in FIG. 2. In FIG. 2, the photodetector 16 is embedded on a
work surface 32. This location is provided by way of example and
not limitation, and other locations can be used as desired or
required by those skilled in the art. For example, the
photodetector may be embedded in a floor, a hallway, or a
stairwell.
[0025] The photodetector 16 sends a signal to the regulator 18 when
the actual light output falls below the target light output. The
signal can be sent electronically or wirelessly, depending on the
desired or required location of the photodetector 16 in relation to
the regulator 18. For example, with the configuration in FIG. 1,
the photodetector 16 can transmit the signal to the regulator 18
electronically, whereas in FIG. 2, the transmission can be
wirelessly.
[0026] The regulator 18 is configured to increase the current to
the at least one LED 14 in response to the signal from the
photodetector 16 so that the target light output is maintained.
Alternatively, the regulator 18 may send current to a supplemental
LED or a plurality of supplemental LEDs to generate the additional
lumens. For example, in FIG. 1, LEDs 14a can be supplemental LEDs
that are only provided current by the regulator 18 when the
photodetector 16 sends a low light output signal. The regulator 18
can be a current regulator, a transistor and Zener diode, a Hall
effect type current sensor, or other regulators known by those
skilled in the art to regulate current.
[0027] It is contemplated that the regulator 18 may be outside of
the lamp 10 and may control the light output and temperature of a
plurality of lamps in series. For example, the regulator may
monitor a plurality of lamps in an area and can increase current to
those lamps when a low output signal is received. The regulator may
monitor a plurality of lamps in an area and send current to another
plurality of supplemental lamps in the same area when a low output
signal is received.
[0028] The thermal sensor 20 of the LED lamp 10 with failure
alerting system is shown in FIG. 1 located within the housing 26
and mounted on the circuit board 24. The thermal sensor 20 is
located to provide an accurate indication of the operating
temperature of the at least one LED 14. The thermal sensor 20
transmits a signal to the regulator 18 indicating the operating
temperature to the regulator 18. The regulator 18 is programmed
with a target temperature which the system is not to exceed. When
the target temperature has been exceeded, the regulator 18 will
reduce the current to the at least one LED 14 until the operating
temperature drops below the target temperature. The target
temperature overrides the low light output signal. In other words,
even if the low light output signal is being transmitted to the
regulator 18, if the signal from the thermal sensor 20 exceeds the
target temperature, the regulator 18 addresses the thermal sensor
signal rather than the low light output signal.
[0029] The location of the thermal sensor 20 on the circuit board
24 shown in FIG. 1 is provided by way of example and not
limitation. It is contemplated that the thermal sensor 20 can be
located on other surfaces with in the housing 26 of the lamp 10.
Types of thermal sensors known by those skilled in the art can be
used, including contact and non-contact sensors.
[0030] The lamp 100 can also include a heat sink (not shown) within
the housing 26 to dissipate the heat generated by the at least one
LED 14. Some of these heat sinks include projections for increasing
the surface area of the heat sink. The heat sinks are typically
formed by extruding billets of material, generally aluminum,
through a die. The thermal sensor 20 protects the LEDs and so
detects the temperature not withstanding the heat sink.
[0031] When the photodetector 16 detects low light for a
predetermined period of time, the photodetector 16 sends a signal
to the low light output indicator 22. When the signal from the
photodetector 16 is received, the low light output indicator 22
produces a low light output signal. In other words, when the actual
light output remains below the target light output because the
regulator 18 can no longer maintain the target light output without
exceeding the target temperature, a low light output signal is
generated.
[0032] The low light output indicator 22 can generate a variety of
signals indicating that the light output is low, depending on the
indication desired or required. The following are provided as
non-limiting examples.
[0033] The low light output signal can be an audible broadcast. For
example, the audible broadcast can be an alarm, a beep, a series of
sounds, or a verbal indication to change the bulb.
[0034] The low light output signal can be a visual signal. For
example, the visual signal can be one or more LEDs within the lamp
that are of a different color, the low light output indicator 22
turning on those one or more LEDs by providing current. The visual
signal can be one or more LEDs that form a shape or word or words
indicating the low output. The visual signal may be one or more
flashing LEDs or a combination of flashing LEDs. The LEDs used to
visually indicate low light output can be supplemental or can be
the currently used LEDs. The visual signal can be a complete
shutdown of the current such that the lamp provides no illumination
to encourage replacement.
[0035] The low light output indicator 22 can be configured to
transmit a wireless signal or broadcast to an external receiver.
The external receiver can than provide an audible or visual
indication of low light output. Other indicators can be used as
desired or required and known to those skilled in the art.
[0036] The low light output indicator 22 may indicate the status of
individual LEDs or a plurality of LEDs as a whole, such as a
plurality of LEDs in one lamp. The low light level indicator 22 can
be tied to a plurality of lights in a common area, wherein the low
light output signal is only generated if the light output of the
area is below a predetermined level.
[0037] FIG. 3 illustrates another embodiment of an LED lamp 100
with a failure alerting system. The lamp 100 is configured for use
in an existing fluorescent fixture. The lamp 100 comprises an LED
lighting unit 102 comprising at least one LED 104, a photodetector
106, a regulator 108, a thermal sensor 110, and a low light output
indicator 112.
[0038] The embodiment illustrated in FIG. 3 operates in the same
manner as the embodiments described in FIGS. 1 and 2. However, the
lamp 100 of this embodiment is made to fit an existing fluorescent
fixture, and so is formed in the same shape as a typical
fluorescent tube with typical pin connections for cooperation with
existing sockets. The illustrative shape of the housing 114 in FIG.
3 is tubular. While not illustrated to scale, the housing 114 can
be approximately 48'' long with a 0.625'', 1.0'', or 1.5'' diameter
for engagement with the typical fluorescent fixture.
[0039] The cover 116 can be made from polycarbonate, acrylic, glass
or another light transmitting material that is transparent or
translucent. For example, a translucent cover 116 can be made from
a composite, such as polycarbonate with particles of a light
refracting material interspersed in the polycarbonate. While the
illustrated housing 114 is cylindrical, the housing 114 or cover
116 can alternatively have a square, triangular, polygonal, or
other cross sectional shape. Similarly, while the illustrated
housing 114 is linear, the housing 114 can have an alternative
shape, e.g., a U-shape.
[0040] The at least one LED 104 is enclosed within the tubular
housing 114 and mounted for emitting light through the cover 116.
At least one electrical connector 118 at a longitudinal end of the
tubular housing 114 is in electrical communication with the at
least one LED 104. The number of LEDs 104 may vary such that the
lamp 100 outputs the desired or required lumens, and the spacing
between the LEDs 104 can also vary. The arrangement of LEDs 104 can
be such as to substantially fill the entire space between ends of
the housing 114.
[0041] The at least one LED 104, photodetector 106, regulator 108,
thermal sensor 110, and low light output indicator 112 of the LED
lighting unit 102 of FIG. 3 can operate in the same manner as
described above with reference to FIGS. 1 and 2 and will therefore
not be repeated.
[0042] Another embodiment disclosed herein is of a failure alerting
system for use with LED lighting fixtures having at least one LED.
The illustrative failure alerting system 200 shown in FIG. 4
comprises a photodetector 202 configured to detect an actual light
output from the at least one LED, a regulator 204 configured to
receive a signal from the photodetector 202 when the actual light
output is below a target light output and to increase a current to
the at least one LED to maintain the target light output, a thermal
sensor 206 configured to sense an operating temperature of the at
least one LED and to control the regulator 204 to increase the
current and the target light output to ensure the operating
temperature does not exceed a target temperature, and a low light
output indicator 208 configured to receive a signal from the
photodetector 202 when the actual light output remains below the
target light output and to produce a low light output signal.
[0043] The photodetector 202, regulator 204, thermal sensor 206 and
low light output indicator 208 of the failure alerting system 200
shown in FIG. 4 are adaptable for use with existing LED lamps of
any configuration. The failure alerting system 200 can be installed
during manufacture or can be installed subsequent to manufacturing
by a purchaser or installer. Once installed, the photodetector 202,
regulator 204, thermal sensor 206 and low light output indicator
208 of the failure alerting system of FIG. 4 can operate in the
same manner as described above with reference to FIGS. 1 and 2 and
will therefore not be repeated.
[0044] Yet another embodiment of a failure alerting system for use
with LED lighting fixtures having at least one LED is disclosed
herein. The illustrative failure alerting system 300 shown in FIG.
5 comprises a photodetector 302 configured to detect an actual
light output from the at least one LED, a regulator 304 configured
to receive a signal from the photodetector 302 when the actual
light output is below a target light output and to increase a
current to the at least one LED to maintain the target light
output, and a low light output indicator 306 configured to receive
a signal from the photodetector 302 when the actual light output
remains below the target light output and to produce a low light
output signal.
[0045] The photodetector 302, regulator 304 and low light output
indicator 306 of the failure alerting system 300 shown in FIG. 5
are adaptable for use with existing LED lamps of any configuration.
The failure alerting system 300 can be installed during manufacture
or can be installed subsequent to manufacturing by a purchaser or
installer. Once installed, the photodetector 302, regulator 304 and
low light output indicator 306 of the failure alerting system of
FIG. 5 can operate in the same manner as described above with
reference to FIGS. 1 and 2.
[0046] When the photodetector 302 detects low light for a
predetermined period of time, the photodetector 302 sends a signal
to the low light output indicator 306. When the signal from the
photodetector 302 is received, the low light output indicator 306
produces a low light output signal. In other words, when the actual
light output remains below the target light output because the
regulator 18 can no longer maintain the target light output, a low
light output signal is generated.
[0047] The low light output indicator 22 can generate a variety of
signals indicating that the light output is low, depending on the
indication desired or required. The examples provided above are
equally applicable for this embodiment.
[0048] While the invention has been described in connection with
certain embodiments, it is to be understood that the invention is
not to be limited to the disclosed embodiments but, on the
contrary, is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended
claims, which scope is to be accorded the broadest interpretation
so as to encompass all such modifications and equivalent structures
as is permitted under the law.
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