U.S. patent application number 16/530747 was filed with the patent office on 2019-11-21 for solid-state lighting with a control gear cascaded by a luminaire.
The applicant listed for this patent is Aleddra Inc.. Invention is credited to Chungho Hsia.
Application Number | 20190357334 16/530747 |
Document ID | / |
Family ID | 68532432 |
Filed Date | 2019-11-21 |
United States Patent
Application |
20190357334 |
Kind Code |
A1 |
Hsia; Chungho |
November 21, 2019 |
Solid-State Lighting With A Control Gear Cascaded By A
Luminaire
Abstract
A light-emitting diode (LED) lighting system comprising a
luminaire and an LED luminaire control gear is used to replace the
luminaire operated with alternate-current (AC) mains. The luminaire
coupled to the LED luminaire control gear comprises LED arrays and
a power supply. The LED luminaire control gear comprises a
rechargeable battery, a current-fed inverter, and a relay switch.
When a line voltage from the AC mains is unavailable, the LED
luminaire control gear is automatically started to provide a high
output voltage within an input operating voltage range of the
luminaire and a low direct-current (DC) voltage to control the
power supply to provide an LED driving voltage greater than a
forward voltage across the LED arrays, eliminating operating
instability of the power supply. The relay switch is configured to
couple either the line voltage or the high output voltage to the
power supply to operate thereon.
Inventors: |
Hsia; Chungho; (Bellevue,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aleddra Inc. |
Renton |
WA |
US |
|
|
Family ID: |
68532432 |
Appl. No.: |
16/530747 |
Filed: |
August 2, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16458823 |
Jul 1, 2019 |
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16530747 |
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16432735 |
Jun 5, 2019 |
10390396 |
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16458823 |
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16401849 |
May 2, 2019 |
10390395 |
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16432735 |
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16296864 |
Mar 8, 2019 |
10390394 |
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16401849 |
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16269510 |
Feb 6, 2019 |
10314123 |
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16296864 |
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16247456 |
Jan 14, 2019 |
10327298 |
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16269510 |
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16208510 |
Dec 3, 2018 |
10237946 |
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16247456 |
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16154707 |
Oct 8, 2018 |
10225905 |
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16208510 |
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15947631 |
Apr 6, 2018 |
10123388 |
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16154707 |
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15911086 |
Mar 3, 2018 |
10136483 |
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15947631 |
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15897106 |
Feb 14, 2018 |
10161616 |
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15911086 |
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15874752 |
Jan 18, 2018 |
10036515 |
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15897106 |
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15836170 |
Dec 8, 2017 |
10021753 |
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15874752 |
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15649392 |
Jul 13, 2017 |
9986619 |
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15836170 |
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15444536 |
Feb 28, 2017 |
9826595 |
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15649392 |
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15362772 |
Nov 28, 2016 |
9967927 |
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15444536 |
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15225748 |
Aug 1, 2016 |
9743484 |
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15362772 |
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14818041 |
Aug 4, 2015 |
9420663 |
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15225748 |
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14688841 |
Apr 16, 2015 |
9288867 |
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14818041 |
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14465174 |
Aug 21, 2014 |
9277603 |
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14688841 |
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14135116 |
Dec 19, 2013 |
9163818 |
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14465174 |
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13525249 |
Jun 15, 2012 |
8749167 |
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14135116 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J 9/065 20130101;
G01R 31/385 20190101; H05B 47/105 20200101; H02J 7/0068 20130101;
H05B 45/382 20200101; H05B 45/50 20200101; H05B 45/39 20200101;
H05B 45/37 20200101 |
International
Class: |
H05B 33/08 20060101
H05B033/08; H02J 9/06 20060101 H02J009/06; G01R 31/385 20060101
G01R031/385; H02J 7/00 20060101 H02J007/00 |
Claims
1. A light-emitting diode (LED) luminaire control gear, comprising:
a rechargeable battery; a full-wave rectifier configured to be
coupled to alternate-current (AC) mains to convert a line voltage
from the AC mains into a first direct-current (DC) voltage; a
charging circuit comprising a first transformer, a feedback control
circuit, a control device, a first electronic switch, a diode, a
first ground reference, and a second ground reference electrically
isolated from the first ground reference, wherein the charging
circuit is configured to be coupled to the full-wave rectifier to
convert the first DC voltage into a second DC voltage that charges
the rechargeable battery to reach a third DC voltage, and wherein
the feedback control circuit is configured to monitor the second DC
voltage and to regulate the control device in response to various
charging voltage and current requirements; a current-fed inverter
comprising a second transformer having a primary side and a
secondary side, wherein the secondary side comprises at least two
windings, wherein the current-fed inverter is configured to receive
the third DC voltage from the rechargeable battery and to convert
the third DC voltage into at least one high output voltage
compatible to a voltage in an input operating voltage range of the
power supply unit and at least one low DC output voltage compatible
to a voltage in a range of 0-to-10 volts when the line voltage from
the AC mains is unavailable; and a line voltage detection and
control circuit comprising a relay switch, wherein the line voltage
detection and control circuit is configured to enable or disable
the current-fed inverter according to availability of the AC mains,
and wherein the relay switch comprises a power sensing coil with a
pick-up voltage and a drop-out voltage and is configured to couple
either the at least one high output voltage or the line voltage
from the AC mains to the external power supply unit to operate
thereon, subsequently powering up external one or more LED arrays
connected with the external power supply unit, wherein: the relay
switch further comprises a first pair of input electrical
terminals, a second pair of input electrical terminals, and a third
pair of input electrical terminals, wherein the first pair of input
electrical terminals are configured to couple to the line voltage
from the AC mains, wherein the second pair of input electrical
terminals are configured to receive the at least one high output
voltage, and wherein the third pair of input electrical terminals
are configured to receive the pick-up voltage to operate the power
sensing coil; and the relay switch further comprises a pair of
output electrical terminals configured to relay either the line
voltage from the AC mains or the at least one high output voltage
to the external power supply unit to operate thereon.
2. The LED luminaire control gear of claim 1, wherein the secondary
side further comprises a rectifier and at least one capacitor, the
rectifier and the at least one capacitor configured to couple to
one of the two windings and to generate the at least one low DC
output voltage when the line voltage from the AC mains is
unavailable.
3. The LED luminaire control gear of claim 1, wherein the at least
one low DC output voltage is configured to control the external
power supply unit to operate with a fraction of power consumed when
the line voltage from the AC mains is available, and wherein a
combination of the at least one low DC output voltage and the at
least one high output voltage is configured to maintain stability
of the external power supply unit in a way that the external one or
more LED arrays are operated without strobing.
4. The LED luminaire control gear of claim 1, wherein the relay
switch comprises a double-pole double-throw (DPDT) configuration,
and wherein either the at least one high output voltage or the line
voltage from the AC mains is configured to be coupled to the
external power supply unit with a return current to respectively
operate thereon without crosstalk.
5. The LED luminaire control gear of claim 1, wherein the line
voltage detection and control circuit further comprises a
transistor circuit configured to couple the third DC voltage to the
current-fed inverter and enable thereon when the line voltage from
the AC mains is unavailable.
6. The LED luminaire control gear of claim 1, wherein the line
voltage detection and control circuit further comprises a flyback
module comprising a diode and a resistor connected in parallel with
the diode, wherein the diode is with a reverse polarity front the
second DC voltage, wherein the flyback module is connected in
parallel with the power sensing coil, and wherein, when the second
DC voltage is greater than the third DC voltage, the pick-up
voltage is built up for the power sensing coil to operate.
7. The LED luminaire control gear of claim 5, wherein the
transistor circuit is further configured to enable or disable the
relay switch to couple either the line voltage from the AC mains or
the at least one high output voltage to the external power supply
unit to operate thereon when the line voltage from the AC mains is
respectively available and unavailable.
8. The LED luminaire control gear of claim 5, wherein the
transistor circuit comprises a first transistor, a first resistor,
and at least one diode, the transistor circuit configured to
receive the second DC voltage and the third DC voltage and to
determine whether the line voltage from the AC mains exists or not,
wherein the first transistor is turned on or off to allow or forbid
a discharge current from the third DC voltage to flow into the
current-fed inverter to enable or disable thereon.
9. The LED luminaire control gear of claim 8, wherein the
transistor circuit further comprises a second transistor, a second
resistor, a voltage regulator, and a resistor-capacitor (RC)
circuit, and wherein the second transistor, the second resistor,
the voltage regulator, and the RC circuit are configured to help
build up bias voltages for the first transistor to operate.
10. The LED luminaire control gear of claim 9, wherein the
transistor circuit further comprises a pair of electrical terminals
coupled between the first resistor and the second resistor, and
wherein the pair of electrical terminals is configured to couple
the first transistor to the second transistor to operate the
transistor circuit when the pair of electrical terminals are
short-circuited.
11. The LED luminaire control gear of claim 10, wherein the pair of
electrical terminals are short-circuited by using a jumper, a
jumper wire, or a switch.
12. The LED luminaire control gear of claim 9, wherein the
transistor circuit further comprises a test switch coupled between
the second DC voltage and the third DC voltage, wherein, when the
test switch is pressed, the drop-out voltage is reached, thereby
disabling the power sensing coil, and wherein, when the test switch
is pressed, the first transistor is turned on to enable the
current-fed inverter.
13. The LED luminaire control gear of claim 1, wherein the primary
side comprises a second electronic switch, a third electronic
switch, an upper portion of a center-tapped winding, a lower
portion of the center-tapped winding, and a center-tapped port
coupled between the upper portion of the center-tapped winding and
the lower portion of the center-tapped winding, wherein the
center-tapped port is coupled to a high-potential electrode of the
rechargeable battery, wherein the upper portion of the
center-tapped winding is driven in one direction of a current flow
with the second electronic switch activated, and wherein the lower
portion of the center-tapped winding is driven in the opposite
direction of the current flow with the third electronic switch
activated.
14. The LED luminaire control gear of claim 13, wherein each of the
second electronic switch and the third electronic switch comprises
a metal-oxide-semiconductor field-effect transistor (MOSFET) or a
transistor.
15. The LED luminaire control gear of claim 1, wherein the first
electronic switch comprises a metal-oxide-semiconductor
field-effect transistor (MOSFET) or a transistor.
16. The LED luminaire control gear of claim 1, wherein the line
voltage detection and control circuit further comprises a first
current guiding diode and a second current guiding diode, the first
current guiding diode and the second current guiding diode
configured to conduct a charging current in one direction and a
discharging current in another direction such that the second DC
voltage is distinct from the third DC voltage.
17. A light-emitting diode (LED) lighting system, comprising: a
luminaire, comprising: one or more LED arrays with an LED forward
voltage; and a power supply unit, comprising: at least two
electrical conductors; an input filter configured to suppress
electromagnetic interference (EMI) noises; a main full-wave
rectifier coupled to the at least two electrical conductors, the
main full-wave rectifier configured to convert a voltage inputted
from the at least two electrical conductors into a fourth
direct-current (DC) voltage; a power switching converter comprising
a main transformer and a power factor correction (PFC) and power
switching circuit, wherein the PFC and power switching circuit is
coupled to the main full-wave rectifier via the input filter and
configured to improve a power factor, to reduce voltage ripples,
and to convert the fourth DC voltage into a fifth DC voltage,
wherein the fifth DC voltage is configured to couple to the one or
more LED arrays to operate thereon, and wherein the power switching
converter further comprises a pulse width modulation (PWM) control
circuit and a pair of input ports configured to receive a 0-to-10 V
(volts) signal, a 1-to-10 V (volts) signal, a PWM signal, or a
signal from a variable resistor for luminaire dimming applications;
and an LED luminaire control gear, comprising: a rechargeable
battery; a full-wave rectifier configured to be coupled to
alternating current (AC) mains to convert a line voltage from the
AC mains into a first DC voltage; a charging circuit comprising a
first transformer, a feedback control circuit, a control device, a
first electronic switch, a diode, a first ground reference, and a
second ground reference electrically isolated from the first ground
reference, wherein the charging circuit is coupled to the full-wave
rectifier and configured to convert the first DC voltage into a
second DC voltage that charges the rechargeable battery to reach a
third DC voltage, and wherein the feedback control circuit is
configured to monitor the second DC voltage and to regulate the
control device in response to various charging voltage and current
requirements; a current-fed inverter comprising a second
transformer having a primary side and a secondary side, wherein the
secondary side comprises at least two windings, wherein the
current-fed inverter is configured to receive the third DC voltage
from the rechargeable battery and to convert the third DC voltage
into at least one high output voltage compatible to a voltage in an
input operating voltage range of the power supply unit and at least
one low DC output voltage compatible to a voltage in a range of
0-to-10 volts when the line voltage from the AC mains is
unavailable; and a line voltage detection and control circuit
comprising a relay switch, wherein the line voltage detection and
control circuit is configured to enable or disable the current-fed
inverter according to availability of the AC mains, and wherein the
relay switch comprises a power sensing coil with a pick-up voltage
and a drop-out voltage and is configured to couple either the at
least one high output voltage or the line voltage from the AC mains
to the power supply unit to operate thereon, subsequently powering
up the one or more LED arrays connected with the power supply unit,
wherein: the at least one low DC output voltage is coupled to the
PWM control circuit via the pair of input ports and configured to
control the fifth DC voltage to be greater than the LED forward
voltage for the one or more LED arrays to operate, avoiding
instability of the fifth DC voltage due to a constant current
operation of the power switching converter; the relay switch
further comprises a first pair of input electrical terminals, a
second pair of input electrical terminals, and a third pair of
input electrical terminals, wherein the first pair of input
electrical terminals are configured to couple to the line voltage
from the AC mains, wherein the second pair of input electrical
terminals are configured to couple to the at least one high output
voltage, and wherein the third pair of input electrical terminals
are configured to receive the pick-up voltage to operate the power
sensing coil; and the relay switch further comprises a pair of
output electrical terminals configured to relay either the line
voltage from the AC mains or the at least one high output voltage
to the power supply unit to operate thereon.
18. The LED lighting system of claim 17, wherein the secondary side
further comprises a rectifier and at least one capacitor, the
rectifier and the at least one capacitor configured to couple to
one of the two windings and to generate the at least one low DC
output voltage when the line voltage from the AC mains is
unavailable.
19. The LED lighting system of claim 17, wherein the at least one
low DC output voltage is configured to control the power switching
converter to operate with a fraction of power consumed when the
line voltage from the AC mains is available, and wherein a
combination of the at least one low DC output voltage and the at
least one high output voltage is configured to maintain stability
of the power switching converter in a way that the one or more LED
arrays are operated without strobing.
20. The LED lighting system of claim 17, wherein the relay switch
comprises a double-pole double-throw (DPDT) configuration, and
wherein either the at least one high output voltage or the line
voltage from the AC mains is configured to be coupled to the power
supply unit with a return current to respectively operate thereon
without crosstalk.
21. The LED lighting system of claim 17, wherein the line voltage
detection and control circuit further comprises a flyback module
comprising a diode and a resistor connected in parallel with the
diode, wherein the diode is with a reverse polarity from the second
DC voltage, wherein the flyback module is connected in parallel
with the power sensing coil, and wherein, when the second DC
voltage is greater than the third DC voltage, the pick-up voltage
is built up for the power sensing coil to operate.
22. The LED lighting system of claim 17, wherein the line voltage
detection and control circuit further comprises a transistor
circuit configured to couple the third DC voltage to the
current-fed inverter and enable thereon when the line voltage from
the AC mains is unavailable.
23. The LED lighting system of claim 22, wherein the transistor
circuit comprises a first transistor, a first resistor, and at
least one diode, the transistor circuit configured to receive the
second DC voltage and the third DC voltage and to determine whether
the line voltage from the AC mains exists or not, wherein the first
transistor is turned on or off to allow or forbid a discharge
current from the third DC voltage to flow into the current-fed
inverter to enable or disable thereon.
24. The LED lighting system of claim 22, wherein the transistor
circuit further comprises a second transistor, a second resistor, a
voltage regulator, and a resistor-capacitor (RC) circuit, and
wherein the second transistor, the second resistor, the voltage
regulator, and the RC circuit are configured to help build up bias
voltages for the first transistor to operate.
25. The LED lighting system of claim 24, wherein the transistor
circuit further comprises a pair of electrical terminals coupled
between the first resistor and the second resistor, and wherein the
pair of electrical terminals is configured to couple the first
transistor to the second transistor to operate the transistor
circuit when the pair of electrical terminals are
short-circuited.
26. The LED lighting system of claim 25 wherein the pair of
electrical terminals are short-circuited by using a jumper, a
jumper wire, or a switch.
27. The LED lighting system of claim 23, wherein the transistor
circuit further comprises a test switch coupled between the second
DC voltage and the third DC voltage, wherein, when the test switch
is pressed, the drop-out voltage is reached, thereby disabling the
power sense coil, and wherein, when the test switch is pressed, the
first transistor is turned on to enable the current-fed
inverter.
28. The LED luminaire control gear of claim 17, wherein the primary
side comprises a second electronic switch, a third electronic
switch, an upper portion of a center-tapped winding, a lower
portion of the center-tapped winding, and a center-tapped port
coupled between the upper portion of the center-tapped winding and
the lower portion of the center-tapped winding, wherein the
center-tapped port is coupled to a high-potential electrode of the
rechargeable battery, wherein the upper portion of the
center-tapped winding is driven in one direction of a current flow
with the second electronic switch activated, and wherein the lower
portion of the center-tapped winding is driven in the opposite
direction of the current flow with the third electronic switch
activated.
29. The LED luminaire control gear of claim 28, wherein each of the
second electronic switch and the third electronic switch comprises
a metal-oxide-semiconductor field-effect transistor (MOSFET) or a
transistor.
30. The LED luminaire control gear of claim 17, wherein the first
electronic switch comprises a metal-oxide-semiconductor
field-effect transistor (MOSFET) or a transistor.
31. The LED luminaire control gear of claim 17, wherein the line
voltage detection and control circuit further comprises a first
current guiding diode and a second current guiding diode, the first
current guiding diode and the second current guiding diode
configured to conduct a charging current in one direction and a
discharging current in another direction such that the second DC
voltage is distinct from the third DC voltage.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present disclosure is part of a continuation-in-part
(CIP) application of U.S. patent application Ser. No. 16/458,823,
filed 1 Jul. 2019, which is part of CIP application of U.S. patent
application Ser. No. 16/432,735, filed 5 Jun. 2019 and issued as
U.S. Pat. No. 10,390,396 on 20 Aug. 2019, which is part of CIP
application of U.S. patent application Ser. No. 16/401,849, filed 2
May 2019 and issued as U.S. Pat. No. 10,390,395 on 20 Aug. 2019,
which is part of CIP application of U.S. patent application Ser.
No. 16/296,864, filed 8 Mar. 2019 and issued as U.S. Pat. No.
10,390,394 on 20 Aug. 2019, which is part of CIP application of
U.S. patent application Ser. No. 16/269,510, filed 6 Feb. 2019 and
issued as U.S. Pat. No. 10,314,123 on 4 Jun. 2019, which is part of
CIP application of U.S. patent application Ser. No. 16/247,456,
filed 14 Jan. 2019 and issued as U.S. Pat. No. 10,327,298 on 18
Jun. 2019, which is part of CIP application of U.S. patent
application Ser. No. 16/208,510, filed 3 Dec. 2018 and issued as
U.S. Pat. No. 10,237,946 on 19 Mar. 2019, which is part of CIP
application of U.S. patent application Ser. No. 16/154,707, filed 8
Oct. 2018 and issued as U.S. Pat. No. 10,225,905 on 5 Mar. 2019,
which is part of a CIP application of U.S. patent application Ser.
No. 15/947,631, filed 6 Apr. 2018 and issued as U.S. Pat. No.
10,123,388 on 6 Nov. 2018, which is part of a CIP application of
U.S. patent application Ser. No. 15/911,086, filed 3 Mar. 2018 and
issued as U.S. Pat. No. 10,136,483 on 20 Nov. 2018, which is part
of a CIP application of U.S. patent application Ser. No.
15/897,106, filed 14 Feb. 2018 and issued as U.S. Pat. No.
10,161,616 on 25 Dec. 2018, which is a CIP application of U.S.
patent application Ser. No. 15/874,752, filed 18 Jan. 2018 and
issued as U.S. Pat. No. 10,036,515 on 31 Jul. 2018, which is a CIP
application of U.S. patent application Ser. No. 15/836,170, filed 8
Dec. 2017 and issued as U.S. Pat. No. 10,021,753 on 10 Jul. 2018,
which is a CIP application of U.S. patent application of Ser. No.
15/649,392 filed 13 Jul. 2017 and issued as U.S. Pat. No. 9,986,619
on 29 May 2018, which is a CIP application of U.S. patent
application Ser. No. 15/444,536, filed 28 Feb. 2017 and issued as
U.S. Pat. No. 9,826,595 on 21 Nov. 2017, which is a CIP application
of U.S. patent application Ser. No. 15/362,772, filed 28 Nov. 2016
and issued as U.S. Pat. No. 9,967,927 on 8 May 2018, which is a CIP
application of U.S. patent application Ser. No. 15/225,748, filed 1
Aug. 2016 and issued as U.S. Pat. No. 9,743,484 on 22 Aug. 2017,
which is a CIP application of U.S. patent application Ser. No.
14/818,041, filed 4 Aug. 2015 and issued as U.S. Pat. No. 9,420,663
on 16 Aug. 2016, which is a CIP application of U.S. patent
application Ser. No. 14/688,841, filed 16 Apr. 2015 and issued as
U.S. Pat. No. 9,288,867 on 15 Mar. 2016, which is a CIP application
of U.S. patent application Ser. No. 14/465,174, filed 21 Aug. 2014
and issued as U.S. Pat. No. 9,277,603 on 1 Mar. 2016, which is a
CIP application of U.S. patent application Ser. No. 14/135,116,
filed 19 Dec. 2013 and issued as U.S. Pat. No. 9,163,818 on 20 Oct.
2015, which is a CIP application of U.S. patent application Ser.
No. 13/525,249, filed 15 Jun. 2012 and issued as U.S. Pat. No.
8,749,167 on 10 Jun. 2014. Contents of the above-identified
applications are incorporated herein by reference in their
entirety.
BACKGROUND
Technical Field
[0002] The present disclosure relates to light-emitting diode (LED)
lighting systems and more particularly to an LED lighting system
that includes an LED luminaire control gear cascaded by a luminaire
to operate the luminaire no matter whether a line voltage from
alternate-current (AC) mains is available or not.
Description of the Related Art
[0003] Solid-state lighting from semiconductor LEDs has received
much attention in general lighting applications today. Because of
its potential for more energy savings, better environmental
protection (with no hazardous materials used), higher efficiency,
smaller size, and longer lifetime than conventional incandescent
bulbs and fluorescent tubes, the LED-based solid-state lighting
will be a mainstream for general lighting in the near future.
Meanwhile, as LED technologies develop with the drive for energy
efficiency and clean technologies worldwide, more families and
organizations will adopt LED lighting for their illumination
applications. In this trend, the potential safety concerns such as
risk of electric shock and fire become especially important and
need to be well addressed.
[0004] In today's retrofit applications of an LED lamp to replace
an existing fluorescent lamp, consumers may choose either to adopt
a ballast-compatible LED lamp with an existing ballast used to
operate the fluorescent lamp or to employ an AC mains-operable LED
lamp by removing/bypassing the ballast. Either application has its
advantages and disadvantages. In the former case, although the
ballast consumes extra power, it is straightforward to replace the
fluorescent lamp without rewiring, which consumers have a first
impression that it is the best alternative. But the fact is that
total cost of ownership for this approach is high regardless of
very low initial cost. For example, the ballast-compatible LED
lamps work only with particular types of ballasts. If the existing
ballast is not compatible with the ballast-compatible LED lamp, the
consumer will have to replace the ballast. Some facilities built
long time ago incorporate different types of fixtures, which
requires extensive labor for both identifying ballasts and
replacing incompatible ones. Moreover, the ballast-compatible LED
lamp can operate longer than the ballast. When an old ballast
fails, a new ballast will be needed to replace in order to keep the
ballast-compatible LED lamps working. Maintenance will be
complicated, sometimes for the lamps and sometimes for the
ballasts. The incurred cost will preponderate over the initial cost
savings by changeover to the ballast-compatible LED lamps for
hundreds of fixtures throughout a facility. In addition, replacing
a failed ballast requires a certified electrician. The labor costs
and long-term maintenance costs will be unacceptable to end users.
From energy saving point of view, a ballast constantly draws power,
even when the ballast-compatible LED lamps are dead or not
installed. In this sense, any energy saved while using the
ballast-compatible LED lamps becomes meaningless with the constant
energy use by the ballast. In the long run, the ballast-compatible
LED lamps are more expensive and less efficient than
self-sustaining AC mains-operable LED lamps.
[0005] On the contrary, an AC mains-operable LED lamp does not
require a ballast to operate. Before use of the AC mains-operable
LED lamp, the ballast in a fixture must be removed or bypassed.
Removing or bypassing the ballast does not require an electrician
and can be replaced by end users. Each AC mains-operable LED lamp
is self-sustaining. Once installed, the AC mains-operable LED lamps
will only need to be replaced after 50,000 hours. In view of above
advantages and disadvantages of both the ballast-compatible LED
lamps and the AC mains-operable LED lamps, it seems that market
needs a most cost-effective solution by using a universal LED lamp
that can be used with the AC mains and is compatible with a ballast
so that LED lamp users can save an initial cost by changeover to
such an LED lamp followed by retrofitting the lamp fixture to be
used with the AC mains when the ballast dies.
[0006] Furthermore, the AC mains-operable LED lamps can easily be
used with emergency lighting, which is especially important in this
consumerism era. The emergency lighting systems in retail sales and
assembly areas with an occupancy load of 100 or more are required
by codes in many cities. Occupational Safety and Health
Administration (OSHA) requires that a building's exit paths be
properly and automatically lighted at least ninety minutes of
illumination at a minimum of 10.8 lux so that an employee with
normal vision can see along the exit route after the building power
becomes unavailable. This means that emergency egress lighting must
operate reliably and effectively during low visibility evacuations.
To ensure reliability and effectiveness of backup lighting,
building owners should abide by the National Fire Protection
Association's (NFPA) emergency egress light requirements that
emphasize performance, operation, power source, and testing. OSHA
requires most commercial buildings to adhere to the NFPA standards
or a significant fine. Meeting OSHA requirements takes time and
investment, but not meeting them could result in fines and even
prosecution. If a building has egress lighting problems that
constitute code violations, the quickest way to fix is to replace
existing lamps with multi-function LED lamps that have an emergency
light package integrated with the normal lighting. The code also
requires the emergency lights be inspected and tested to ensure
they are in proper working conditions at all times. It is,
therefore, the manufacturers' responsibility to design an LED lamp,
an LED luminaire, or an LED lighting system with an LED luminaire
control gear such that after the LED lamp or the LED luminaire is
installed on a ceiling or in a room, the LED luminaire control gear
with an emergency battery system can be readily connected with the
LED lamp or the LED luminaire on site to meet regulatory
requirements, especially without further retrofits or modifications
of the LED lamp or the LED luminaire.
SUMMARY
[0007] An LED lighting system comprising a luminaire and an LED
luminaire control gear cascaded by the luminaire is used to replace
a fluorescent or an LED lamp normally operated with the AC mains.
The luminaire comprises one or more LED arrays with a forward
voltage across thereon and a power supply unit that powers the one
or more LED arrays. The LED luminaire control gear comprises a
rechargeable battery, a line voltage detection and control circuit,
and a current-fed inverter configured to receive power from the
rechargeable battery and to generate at least one high output
voltage, V.sub.H, and at least one low direct-current (DC) output
voltage, V.sub.L, when the line voltage from the AC mains is
unavailable. The at least one high output voltage, V.sub.H, is
compatible to a voltage in an input operating voltage range of the
power supply unit whereas the at least one low DC output voltage is
compatible to a voltage in a range of 0-to-10 volts. The line
voltage detection and control circuit comprises a relay switch
configured to couple either the line voltage from the AC mains or
the at least one high output voltage, V.sub.H, to the power supply
unit to operate thereon. The line voltage detection and control
circuit further comprises a transistor circuit configured to enable
the current-fed inverter.
[0008] The power supply unit comprises at least two electrical
conductors, a main full-wave rectifier, and an input filter. The at
least two electrical conductors are configured to couple to the LED
luminaire control gear, receiving either the line voltage from the
AC mains or the at least one high output voltage, V.sub.H. The main
full-wave rectifier is coupled to the at least two electrical
conductors to convert either the line voltage from the AC mains or
the at least one high output voltage, V.sub.H, into a fourth DC
voltage. The input filter is configured to suppress electromagnetic
interference (EMI) noises. The power supply unit further comprises
a power switching converter comprising a main transformer and a
power factor correction (PFC) and power switching circuit. The PFC
and power switching circuit is coupled to the main full-wave
rectifier via the input filter and configured to improve a power
factor, to reduce voltage ripples, and to convert the fourth DC
voltage into a fifth DC voltage. The fifth DC voltage is configured
to couple to the one or more LED arrays to operate thereon. The
power switching converter further comprises a pulse width
modulation (PWM) control circuit and a pair of input ports
configured to receive a 0-to-10 V signal, a 1-to-10 V signal, a PWM
signal, or a signal from a variable resistor for luminaire dimming
applications. The PFC and power switching circuit is generally a
current source, in which when the one or more LED arrays require
more current than a predetermined maximum, the fifth DC voltage
drops accordingly to maintain power conservation. In other words,
when the LED luminaire control gear is cascaded by the luminaire
powered by the LED luminaire control gear that only provides a
fraction of power compared with a rated power of the luminaire,
there exists an operating uncertainty that a driving voltage and
current provided by the LED luminaire control gear to drive the one
or more LED arrays may fall into an unstable operating situation.
That is, when the one or more LED arrays require more current than
a predetermined maximum, the fifth DC voltage drops below the
forward voltage of the one or more LED arrays, resulting in an
operating failure of the one or more LED arrays. When the power
supply unit recovers to start tracking current, the fifth DC
voltage recovers to an original level, thereby temporarily
operating the one or more LED arrays. Such a voltage and current
competition continues, creating a phenomenon called luminaire
strobing. Therefore, the LED luminaire control gear must provide an
additional signal to control the power supply unit to operate
stably and efficiently the one or more LED arrays at low power
conditions.
[0009] The LED luminaire control gear further comprises a full-wave
rectifier and a charging circuit. The full-wave rectifier is
coupled to the AC mains and configured to convert the line voltage
from the AC mains into a first DC voltage. The charging circuit
comprises a first transformer, a feedback control circuit, a
control device, a first electronic switch, a diode, a first ground
reference, and a second ground reference electrically isolated from
the first ground reference. The first electronic switch comprises a
metal-oxide-semiconductor field-effect transistor (MOSFET) or a
transistor. The charging circuit is coupled to the full-wave
rectifier and configured to convert the first DC voltage into a
second DC voltage that charges the rechargeable battery to reach a
third DC voltage. The feedback control circuit is configured to
monitor the second DC voltage and to regulate the control device in
response to various charging requirements. The current-fed inverter
comprises a second transformer having a primary side and a
secondary side. The secondary side comprises at least two windings.
The current-fed inverter is configured to receive the third DC
voltage from the rechargeable battery and to convert the third DC
voltage into the at least one high output voltage, V.sub.H, and the
at least one low DC output voltage, V.sub.L, when the line voltage
from the AC mains is unavailable. The at least one low DC output
voltage, V.sub.L, is coupled to the PWM control circuit via the
pair of input ports and configured to control the fifth DC voltage
to be greater than the LED forward voltage for the one or more LED
arrays to operate, avoiding instability of the fifth DC voltage due
to the voltage and current competition in a constant
current-limiting operation of the power switching converter. The
secondary side further comprises a rectifier and at least one
capacitor, the rectifier and the at least one capacitor configured
to couple to one of the two windings and to generate the at least
one low DC output voltage, V.sub.L, when the line voltage from the
AC mains is unavailable. The at least one low DC output voltage,
V.sub.L, is configured to control the power switching converter to
operate with a fraction of power consumed when the line voltage
from the AC mains is available, whereas a combination of the at
least one low DC output voltage, V.sub.L, and the at least one high
output voltage, V.sub.H, is configured to maintain stability of the
power switching converter in a way that the one or more LED arrays
are operated without strobing. The primary side comprises a second
electronic switch, a third electronic switch, an upper portion of a
center-tapped winding, a lower portion of the center-tapped
winding, and a center-tapped port coupled between the upper portion
of the center-tapped winding and the lower portion of the
center-tapped winding. The center-tapped port is coupled to a
high-potential electrode of the rechargeable battery. The upper
portion of the center-tapped winding is driven in one direction of
a current flow with the second electronic switch activated, whereas
the lower portion of the center-tapped winding is driven in the
opposite direction of the current flow with the third electronic
switch activated. Each of the second electronic switch and the
third electronic switch comprises a metal-oxide-semiconductor
field-effect transistor (MOSFET) or a transistor.
[0010] The relay switch comprises a power sensing coil with a
pick-up voltage and a drop-out voltage and is configured to couple
either the at least one high output voltage, V.sub.H, or the line
voltage from the AC mains to the power supply unit to operate
thereon, subsequently powering up the one or more LED arrays
connected with the power supply unit. The relay switch further
comprises a first pair of input electrical terminals, a second pair
of input electrical terminals, and a third pair of input electrical
terminals. The first pair of input electrical terminals are
configured to couple to the line voltage from the AC mains, whereas
the second pair of input electrical terminals are configured to
couple to the at least one high output voltage, V.sub.H. The third
pair of input electrical terminals are configured to receive the
pick-up voltage to operate the power sensing coil. The relay switch
further comprises a pair of output electrical terminals configured
to relay either the line voltage from the AC mains or the at least
one high output voltage, V.sub.H, to the power supply unit to
operate thereon. In this case, the relay switch comprises a
double-pole double-throw (DPDT) configuration, in which either the
at least one high output voltage, V.sub.H, and the line voltage
from the AC mains can be coupled to the power supply unit with a
return current to respectively operate thereon without crosstalk.
The at least one high output voltage, V.sub.H, is within an input
operating voltage range of the power supply unit to guarantee that
an under-voltage lockout will never occur.
[0011] The line voltage detection and control circuit further
comprises a flyback module comprising a diode and a resistor
connected in parallel with the diode, in which the diode is with a
reverse polarity from the second DC voltage. The flyback module is
connected in parallel with the power sensing coil. When the second
DC voltage is greater than the third DC voltage, the pick-up
voltage is built up for the power sensing coil to operate. The
transistor circuit comprises a first transistor, a first resistor,
and at least one diode and is configured to couple to the second DC
voltage and the third DC voltage and to determine whether the line
voltage from the AC mains is available or not. The first transistor
is turned on or off to allow or forbid a discharge current from the
third DC voltage to flow into the current-fed inverter to enable
and disable thereon. The transistor circuit further comprises a
second transistor, a second resistor, a voltage regulator, and a
resistor-capacitor (RC) circuit. The second transistor, the second
resistor, the voltage regulator, and the RC circuit are configured
to couple to the first transistor to operate thereon. The
transistor circuit further comprises a pair of electrical terminals
coupled between the first resistor and the second resistor. The
pair of electrical terminals are configured to couple the first
transistor to the second transistor to operate the transistor
circuit when the pair of electrical terminals are short-circuited.
The pair of electrical terminals may be short-circuited by using a
jumper, a jumper wire, or a switch. The transistor circuit further
comprises a test switch coupled between the second DC voltage and
the third DC voltage. When the test switch is pressed, the drop-out
voltage is reached, thereby disabling the power sensing coil. In
this case, the first transistor is turned on to enable the
current-fed inverter. The line voltage detection and control
circuit further comprises a first current guiding diode and a
second current guiding diode. The first current guiding diode and
the second current guiding diode are configured to conduct a
charging current in one direction and a discharging current in
another direction such that the second DC voltage is distinct from
the third DC voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Non-limiting and non-exhaustive embodiments of the present
disclosure are described with reference to the following figures,
wherein like reference numerals refer to like parts throughout the
various figures unless otherwise specified. Moreover, in the
section of detailed description of the invention, any of a first, a
second, a third, and so forth does not necessarily represent a part
that is mentioned in an ordinal manner, but a particular one.
[0013] FIG. 1 is a block diagram of an LED luminaire control gear
according to the present disclosure.
[0014] FIG. 2 is a block diagram of a current-fed inverter
according to the present disclosure.
[0015] FIG. 3 is a block diagram of a transistor circuit according
to the present disclosure.
[0016] FIG. 4 is a block diagram of an LED lighting system with an
LED luminaire control gear cascaded by a luminaire according to the
present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIG. 1 is a block diagram of an LED luminaire control gear
according to the present disclosure. The LED luminaire control gear
800 comprises a rechargeable battery 500, a full-wave rectifier
401, an input filter 402, a charging circuit 403, a current-fed
inverter 600, and a line voltage detection and control circuit 700.
In FIG. 1, the full-wave rectifier 401 is coupled to the AC mains
and configured to convert the line voltage from the AC mains
denoted as "L" and "N" into a first DC voltage, V1, after the input
filter 402. The charging circuit 403 is an isolated step-down
converter and comprises a first ground reference 254, a second
ground reference 255 electrically isolated from the first ground
reference 254, a transformer 404, a feedback control circuit 405, a
control device 406, a first electronic switch 407, and a diode 408.
The charging circuit 403 is coupled to the full-wave rectifier 401
via the input filter 402 and configured to convert the first DC
voltage, V1, into a second DC voltage, V2, that charges the
rechargeable battery 500 to reach a third DC voltage, V3. The
feedback control circuit 405 is configured to monitor the second DC
voltage, V2, and to regulate the control device 406 according to
charging voltage and current requirements. The transformer 404
comprises a primary winding coupled to the first ground reference
254 and a secondary winding coupled to the second ground reference
255. The transformer 404 is configured to provide electrical
isolation between the AC mains and the second DC voltage, V2, with
respect to the second ground reference 255.
[0018] FIG. 2 is a block diagram of a current-fed inverter
according to the present disclosure. Referring to FIG. 1 and FIG.
2, the current-fed inverter 600 comprises a second transformer 601
having a primary side 610 and a secondary side 620. The secondary
side 620 comprises at least two windings 621 and 622. The
current-fed inverter 600 is configured to receive the third DC
voltage, V3, from the rechargeable battery 500 and to convert the
third DC voltage, V3, into at least one high output voltage,
V.sub.H, and at least one low DC output voltage, V.sub.L, when the
line voltage from the AC mains is unavailable. The at least one
high output voltage, V.sub.H, is compatible to a voltage in an
input operating voltage range of the power supply unit whereas the
at least one low DC output voltage is compatible to a voltage in a
range of 0-to-10 volts. The secondary side 620 further comprises a
rectifier 623 and at least one capacitor 624. The rectifier 623 and
the at least one capacitor 624 are configured to couple to one of
the two windings 621 and 622 and to generate the at least one low
DC output voltage, V.sub.L, when the line voltage from the AC mains
is unavailable. The at least one low DC output voltage, V.sub.L, is
coupled to an external power supply unit 300 via a pair of output
ports denoted as "DD'" and configured to control the external power
supply unit 300 in an external luminaire 200 to operate with a
fraction of power consumed when the line voltage from the AC mains
is available, whereas a combination of the at least one low DC
output voltage, V.sub.L, and the at least one high output voltage,
V.sub.H, is configured to maintain stability of the external power
supply unit 300 in a way that external one or more LED arrays 214
connected to the external power supply unit 300 are operated
without strobing. The primary side 610 comprises a control unit
611, a second electronic switch 612, a third electronic switch 613,
an upper portion 615 of a center-tapped winding, a lower portion
616 of the center-tapped winding, and a center-tapped port 617
coupled between the upper portion 615 of the center-tapped winding
and the lower portion 616 of the center-tapped winding. The
center-tapped port 617 may be directly coupled to a high-potential
electrode of the rechargeable battery 500 or via an inductor 614.
The upper portion 615 of the center-tapped winding is driven in one
direction of a current flow with the second electronic switch 612
activated, whereas the lower portion 616 of the center-tapped
winding is driven in the opposite direction of the current flow
with the third electronic switch 613 activated. Each of the first
electronic switch 407, the second electronic switch 612, and the
third electronic switch 613 comprises a metal-oxide-semiconductor
field-effect transistor (MOSFET) or a transistor.
[0019] In FIG. 1, the line voltage detection and control circuit
700 comprising a relay switch 731 comprises a power sensing coil
732 with a pick-up voltage and a drop-out voltage and is configured
to couple either the at least one high output voltage, V.sub.H, or
the line voltage from the AC mains to the external power supply
unit 300 to operate thereon, subsequently powering up the one or
more LED arrays 214 connected with the external power supply unit
300. The relay switch 731 further comprises a first pair, a second
pair, and a third pair of input electrical terminals. The first
pair of input electrical terminals denoted as "L" and "N" are
configured to couple to the line voltage from the AC mains, whereas
the second pair of input electrical terminals denoted as "BB'" are
configured to couple to the at least one high output voltage,
V.sub.H. The third pair of input electrical terminals denoted as
"EE'" are configured to receive the pick-up voltage to operate the
power sensing coil 732. The relay switch 731 further comprises a
pair of output electrical terminals denoted as "CC'" configured to
relay either the line voltage from the AC mains or the at least one
high output voltage, V.sub.H, to the external power supply unit 300
to operate thereon. In this case, the relay switch 731 comprises a
double-pole double-throw (DPDT) configuration, in which either the
line voltage from the AC mains or the at least one high output
voltage, V.sub.H, can be simultaneously coupled to the external
power supply unit 300 to respectively operate thereon without
crosstalk. Although both the line voltage from the AC mains and the
at least one high output voltage, V.sub.H, can operate the external
power supply unit 300, the at least one high output voltage,
V.sub.H, is less than the line voltage from the AC mains.
Nevertheless, the at least one high output voltage, V.sub.H, is
within an input operating voltage range of the external power
supply unit 300 to avoid the under-voltage lockout occurring.
Besides, the current-fed inverter 600 provides a fraction of power
the external power supply unit 300 consumes when the line voltage
from the AC mains is available.
[0020] In FIG. 1, the line voltage detection and control circuit
700 further comprises a transistor circuit 711. The transistor
circuit 711 is configured to enable and disable the current-fed
inverter 600 via a port denoted as "A" according to availability of
the AC mains. The transistor circuit 711 is further configured to
disable the relay switch 731 when required. The line voltage
detection and control circuit 700 further comprises a flyback
module 721 comprising a diode 722 and a resistor 723 connected in
parallel with the diode 722, in which the diode 722 is with a
reverse polarity from the second DC voltage, V2. The flyback module
721 is connected in parallel with the power sensing coil 732. When
the second DC voltage, V2, is greater than the third DC voltage,
V3, the pick-up voltage is built up for the power sensing coil 732
to operate. In FIG. 1, the line voltage detection and control
circuit 700 further comprises a first and a second current guiding
diodes 431 and 432. The first current guiding diode 431 and the
second current guiding diode 432 are configured to conduct a
charging current in one direction and a discharging current in
another direction such that the second DC voltage, V2, is distinct
from the third DC voltage, V3. The charging circuit 403 may further
comprise at least one capacitor (not shown) between the second DC
voltage, V2, and the second ground reference 255.
[0021] FIG. 3 is a block diagram of the transistor circuit
according to the present disclosure. The transistor circuit 711
comprises a first transistor 712, a first resistor 713, and at
least one diode 714 and is configured to couple to the second DC
voltage, V2, and the third DC voltage, V3, and to determine whether
the line voltage from the AC mains is available or not. The first
transistor 712 is turned on or off to allow or forbid the discharge
current from the third DC voltage, V3, to flow into the current-fed
inverter 600 to enable and disable thereon. The transistor circuit
711 further comprises a second transistor 716, a second resistor
717, a voltage regulator 718, and a resistor-capacitor (RC) circuit
719. The second transistor 716, the second resistor 717, the
voltage regulator 718, and the RC circuit 719 are configured to
couple to the first transistor 712 to operate thereon. The
transistor circuit 711 further comprises a pair of electrical
terminals 715 coupled between the first resistor 713 and the second
resistor 717, in which the pair of electrical terminals 715 is
configured to couple the first transistor 712 to the second
transistor 716 to operate the transistor circuit 711 when the pair
of electrical terminals 715 are short-circuited. The pair of
electrical terminals 715 may be short-circuited by using a jumper,
a jumper wire, or a switch. The transistor circuit 711 further
comprises a test switch 720 coupled between the second DC voltage,
V2, and the third DC voltage, V3. When the test switch 720 is
pressed, the drop-out voltage is reached, thereby disabling the
power sensing coil 732. In this case, the first transistor 712 is
turned on to enable the current-fed inverter 600 via the port
denoted as "A".
[0022] FIG. 4 is a block diagram of an LED lighting system with an
LED luminaire control gear according to the present disclosure. In
FIG. 4, the LED lighting system 100 comprises a luminaire 200 and
an LED luminaire control gear 800. The LED luminaire control gear
800 is basically the same as depicted in FIG. 1. The luminaire 200
comprises one or more LED arrays 214 with a forward voltage across
thereon and a power supply unit 300 originally designed to receive
the line voltage from the AC mains at ports denoted as "CC'" for
high-power lighting applications. When the line voltage from the AC
mains is inputted, the power supply unit 300 generates a fifth DC
voltage and a rated current to normally operate the one or more LED
arrays 214. However, the LED luminaire control gear 800 is cascaded
by the luminaire 200 powered by the LED luminaire control gear 800.
When the line voltage from the AC mains is unavailable, the LED
luminaire control gear 800 is automatically started to provide the
at least one high output voltage, V.sub.H, to the luminaire 200
with a fraction of rated power. Thereby, the power supply unit 300
is unable to provide a sufficient driving current to drive the one
or more LED arrays 214. In this case, a phenomenon of strobing on
the luminaire 200 may occur.
[0023] In FIG. 4, the LED luminaire control gear 800 comprises a
rechargeable battery 500, a full-wave rectifier 401, an input
filter 402, a charging circuit 403, a current-fed inverter 600, and
a line voltage detection and control circuit 700. In FIG. 4, the
full-wave rectifier 401 is coupled to the AC mains and configured
to convert the line voltage from the AC mains denoted as "L" and
"N" into a first DC voltage, V1, after the input filter 402. The
charging circuit 403 is an isolated step-down converter and
comprises a first ground reference 254, a second ground reference
255 electrically isolated from the first ground reference 254, a
transformer 404, a feedback control circuit 405, a control device
406, a first electronic switch 407, and a diode 408. The charging
circuit 403 is coupled to the full-wave rectifier 401 via the input
filter 402 and configured to convert the first DC voltage, V1, into
a second DC voltage, V2, that charges the rechargeable battery 500
to reach a third DC voltage, V3. The feedback control circuit 405
is configured to monitor the second DC voltage, V2, and to regulate
the control device 406 according to charging voltage and current
requirements. The transformer 404 comprises a primary winding
coupled to the first ground reference 254 and a secondary winding
coupled to the second ground reference 255. The transformer 404 is
configured to provide electrical isolation between the AC mains and
the second DC voltage, V2, with respect to the second ground
reference 255.
[0024] In FIG. 4, the current-fed inverter 600 comprises a second
transformer 601 having a primary side 610 and a secondary side 620.
The secondary side 620 comprises at least two windings 621 and 622.
The current-fed inverter 600 is configured to receive the third DC
voltage, V3, from the rechargeable battery 500 and to convert the
third DC voltage, V3, into at least one high output voltage,
V.sub.H, and at least one low DC output voltage, V.sub.L, when the
line voltage from the AC mains is unavailable. The at least one
high output voltage, V.sub.H, is compatible to a voltage in an
input operating voltage range of the power supply unit 300 whereas
the at least one low DC output voltage is compatible to a voltage
in a range of 0-to-10 volts. The secondary side 620 further
comprises a rectifier 623 and at least one capacitor 624. The
rectifier 623 and the at least one capacitor 624 are configured to
couple to one of the two windings 621 and 622 and to generate the
at least one low DC output voltage, V.sub.L, when the line voltage
from the AC mains is unavailable. The at least one low DC output
voltage, V.sub.L, is configured to control the power supply unit
300 to operate with a fraction of power consumed when the line
voltage from the AC mains is available, whereas a combination of
the at least one low DC output voltage V.sub.L, and the at least
one high output voltage, V.sub.H, is configured to maintain
stability of the power supply unit 300 in a way that the one or
more LED arrays 214 are operated without strobing. The primary side
610 comprises a control unit 611, a second electronic switch 612, a
third electronic switch 613, an upper portion 615 of a
center-tapped winding, a lower portion 616 of the center-tapped
winding, and a center-tapped port 617 coupled between the upper
portion 615 of the center-tapped winding and the lower portion 616
of the center-tapped winding. The center-tapped port 617 is coupled
to a high-potential electrode of the rechargeable battery 500 via
an inductor 614. The upper portion 615 of the center-tapped winding
is driven in one direction of a current flow with the second
electronic switch 612 activated, whereas the lower portion 616 of
the center-tapped winding is driven in the opposite direction of
the current flow with the third electronic switch 613 activated.
Each of the first electronic switch 407, the second electronic
switch 612, and the third electronic switch 613 comprises a
metal-oxide-semiconductor field-effect transistor (MOSFET) or a
transistor.
[0025] In FIG. 4, the line voltage detection and control circuit
700 comprises a relay switch 731. The relay switch 731 comprises a
power sensing coil 732 with a pick-up voltage and a drop-out
voltage and is configured to couple either the at least one high
output voltage, V.sub.H, or the line voltage from the AC mains to
the power supply unit 300 to operate thereon, subsequently powering
up one or more LED arrays 214 connected with the power supply unit
300. The line voltage detection and control circuit 700 further
comprises a transistor circuit 711. The transistor circuit 711 is
configured to enable and disable the current-fed inverter 600 via a
port denoted as "A" according to availability of the AC mains. The
transistor circuit 711 is further configured to disable the relay
switch 731 when required. The relay switch 731 further comprises a
first pair, a second pair, and a third pair of input electrical
terminals. The first pair of input electrical terminals denoted as
"L" and "N" are configured to couple to the line voltage from the
AC mains, whereas the second pair of input electrical terminals
denoted as "BB'" are configured to couple to the at least one high
output voltage, V.sub.H. The third pair of input electrical
terminals denoted as "EE'" are configured to receive the pick-up
voltage to operate the power sensing coil 732. The relay switch 731
further comprises a pair of output electrical terminals denoted as
"CC'" configured to relay either the line voltage from the AC mains
or the at least one high output voltage, V.sub.H, to the power
supply unit 300 to operate thereon. In this case, the relay switch
731 comprises a double-pole double-throw (DPDT) configuration, in
which either the line voltage from the AC mains or the at least one
high output voltage, V.sub.H, can be simultaneously coupled to the
power supply unit 300 to respectively operate thereon without
crosstalk. Although both the line voltage from the AC mains and the
at least one high output voltage, V.sub.H, can operate the external
power supply unit 300, the at least one high output voltage,
V.sub.H, may be less than the line voltage from the AC mains.
Nevertheless, the at least one high output voltage, V.sub.H, is
within an input operating voltage range of the power supply unit
300 to avoid the under-voltage lockout occurring. Besides, the
current-fed inverter 600 provides a fraction of power the power
supply unit 300 consumes when the line voltage from the AC mains is
available.
[0026] In FIG. 4, the line voltage detection and control circuit
700 further comprises a flyback module 721 comprising a diode 722
and a resistor 723 connected in parallel with the diode 722, in
which the diode 722 is with a reverse polarity from the second DC
voltage, V2. The flyback module 721 is connected in parallel with
the power sensing coil 732. When the second DC voltage, V2, is
greater than the third DC voltage, V3, the pick-up voltage is built
up for the power sensing coil 732 to operate. In FIG. 4, the line
voltage detection and control circuit 700 further comprises a first
and a second current guiding diodes 431 and 432. The first current
guiding diode 431 and the second current guiding diode 432 are
configured to conduct a charging current in one direction and a
discharging current in another direction such that the second DC
voltage, V2, is distinct from the third DC voltage, V3. The
charging circuit 403 may further comprise at least one capacitor
(not shown) between the second DC voltage, V2, and the second
ground reference 255.
[0027] In FIG. 4, the power supply unit 300 comprises at least two
electrical conductors denoted as "C" and "C", a main full-wave
rectifier 301, and an input filter 302. The at least two electrical
conductors denoted as "C" and "C'" are configured to couple to
"CC'" ports in the LED luminaire control gear 800 and to convert
either the line voltage from the AC mains or the at least one high
output voltage V.sub.H into a fourth DC voltage, V4. The input
filter 302 is configured to suppress electromagnetic interference
(EMI) noises. The power supply unit 300 further comprises a power
switching converter 303 comprising a main transformer 304 and a
power factor correction (PFC) and power switching circuit 305. The
PFC and power switching circuit 305 is coupled to the main
full-wave rectifier 301 via the input filter 302 and configured to
improve a power factor, to reduce voltage ripples, and to convert
the fourth DC voltage into a fifth DC voltage. The fifth DC voltage
is configured to couple to the one or more LED arrays 214 to
operate thereon. The power switching converter 303 further
comprises a pulse width modulation (PWM) control circuit 306 and a
pair of input ports denoted as "DD'" configured to receive a
0-to-10 V signal, a 1-to-10 V signal, a PWM signal, or a signal
from a variable resistor for luminaire dimming applications. The
pair of input ports denoted as "DD'" are coupled to the current-fed
inverter 600 to receive the at least one low DC output voltage,
V.sub.L. The PFC and power switching circuit 305 is basically a
current source, in which when the one or more LED arrays require
more current than a predetermined maximum, the fifth DC voltage
drops accordingly to maintain power conservation. In FIG. 2,
although configured to directly couple to the winding 621 without
rectifiers and filters, the at least one high output voltage
V.sub.H may be a DC voltage via the rectifiers and the filters
coupled to the winding 621. If this is the case, the main full-wave
rectifier 301 in FIG. 4 can still pass such a DC voltage to the
power switching converter 303 to work.
[0028] Whereas preferred embodiments of the present disclosure have
been shown and described, it will be realized that alterations,
modifications, and improvements may be made thereto without
departing from the scope of the following claims. Another kind of
schemes with an LED luminaire control gear adopted in an LED
lighting system to operate a luminaire using various kinds of
combinations to accomplish the same or different objectives could
be easily adapted for use from the present disclosure. Accordingly,
the foregoing descriptions and attached drawings are by way of
example only and are not intended to be limiting.
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