U.S. patent application number 11/518576 was filed with the patent office on 2007-01-04 for electronic lighting ballast.
Invention is credited to Ronald Flores, Igor Pogodayev, Vatche Vorperian.
Application Number | 20070001617 11/518576 |
Document ID | / |
Family ID | 34557375 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070001617 |
Kind Code |
A1 |
Pogodayev; Igor ; et
al. |
January 4, 2007 |
Electronic lighting ballast
Abstract
An electronics enclosure has a mains input and a lamp output. A
power factor correction circuit is installed in the enclosure, to
provide a DC output voltage. An inverter is also installed in the
enclosure. Control electronics is also installed in the enclosure
to control the inverter, and to receive a selection of lamp load
type made manually by a user via a user interface on an outside
face of the enclosure. The same lamp output can thus alternatively
drive, for example, a high pressure sodium lamp and a metal halide
lamp, as indicated by the selection. Other embodiments are also
described and claimed.
Inventors: |
Pogodayev; Igor; (Huntington
Beach, CA) ; Vorperian; Vatche; (Irvine, CA) ;
Flores; Ronald; (Huntington Beach, CA) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN
12400 WILSHIRE BOULEVARD
SEVENTH FLOOR
LOS ANGELES
CA
90025-1030
US
|
Family ID: |
34557375 |
Appl. No.: |
11/518576 |
Filed: |
September 8, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10975203 |
Oct 27, 2004 |
7109668 |
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11518576 |
Sep 8, 2006 |
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60516036 |
Oct 30, 2003 |
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60603406 |
Aug 20, 2004 |
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Current U.S.
Class: |
315/224 |
Current CPC
Class: |
H05B 41/282 20130101;
H05B 41/245 20130101; Y02B 20/183 20130101; Y02B 20/00 20130101;
H05B 41/36 20130101 |
Class at
Publication: |
315/224 |
International
Class: |
H05B 41/36 20060101
H05B041/36 |
Claims
1. A method for lighting control, comprising: deploying a plurality
of high intensity discharge (HID) lamp ballasts in a lighting
application, each of the ballasts integrates switching power supply
circuitry and control electronics in a respective enclosure that
implements a dimming function, an output on/off function,
adjustable output power, ability to drive different types of HID
lamps, and ability to drive HID lamps from different manufacturers;
and setting a dimmer level, output on/off, output power, and HID
lamp type for each of the ballasts in accordance with the lighting
application.
2. The method of claim 1 wherein each of the ballasts can drive no
more than one high intensity discharge lamp at any one time.
3. The method of claim 2 wherein each of the ballasts are
essentially replicates from a standpoint of hardware.
4. The method of claim 3 wherein setting one or more of the dimmer
level, output on/off, output power, lamp type and lamp manufacturer
output for each of the ballasts is performed via a respective user
interface that is built into the enclosure.
5. The method of claim 4 wherein each of the ballasts integrates
within the respective enclosure a scheduler function, the method
further comprising setting timed operation for one of the ballasts
via its respective user interface.
6. The method of claim 3 wherein setting one or more of the dimmer
level, output power, and lamp type for each of the ballasts is
performed from a graphical user interface running in a central,
remote machine to which the ballasts are communicatively
coupled.
7. The method of claim 6 further comprising setting an output
on/off schedule for each of the ballasts via the graphical user
interface.
8. The method of claim 7 further comprising: receiving at the
central, remote machine from each of the ballasts a report
indicating a failure or impending failure of a respective lamp.
9. A lighting control element comprising: an electronic high
intensity discharge (HID) lamp ballast that integrates switching
power supply circuitry and control electronics in its enclosure to
implement adjustable input voltage, a lamp dimming function, a lamp
on/off function, adjustable output power, ability to drive
different types of HID lamps through the same output including high
pressure sodium (HPS) and metal halide (MH), ability to drive HID
lamps of different manufacturers through the same output, and
ability to communicate with a remote central computer as part of a
lighting network, wherein the ballast is to, in response to
commands received from the remote central computer, set its dimmer
level, lamp on/off, output power level, and HID lamp type to be
driven.
10. The lighting control element of claim 9 wherein the ballast is
to drive no more than one HID lamp at any one time.
11. The lighting control element of claim 9 wherein the ballast
integrates in its enclosure a user interface to set its dimmer
level, lamp on/off, output power level, and HID lamp type to be
driven.
12. The lighting control element of claim 9 wherein the ballast
integrates in its enclosure a scheduler function and a user
interface to set its timed operation using the scheduler
function.
13. The lighting control element of claim 9 wherein the ballast is
to send a report indicating its failure or impending failure to the
remote central computer.
14. A lighting control network comprising: a plurality of
electronic high intensity discharge (HID) lamp ballasts, wherein
each ballast integrates switching power supply circuitry and
control electronics in its respective enclosure to implement
adjustable input voltage, a lamp dimming function, a lamp on/off
function, adjustable output power, ability to drive different types
of HID lamps through the same output including high pressure sodium
(HPS) and metal halide (MH), ability to drive HID lamps of
different manufacturers through the same output, and ability to
communicate with a remote central computer as part of a lighting
network; and a lighting control application program to run in the
remote central computer, the program having a graphical user
interface in which a dimmer level, lamp on/off, output power level,
and HID lamp type to be driven by each of the ballasts is to be set
by a user.
15. The lighting control network of claim 14 wherein each of the
ballasts is to drive no more than one HID lamp at any one time.
16. The lighting control network of claim 14 wherein each of the
ballasts integrates in its enclosure a user interface to set its
dimmer level, lamp on/off, output power level, and HID lamp type to
be driven.
17. The lighting control network of claim 14 wherein each of the
ballasts integrates in its enclosure a scheduler function and a
user interface to set its timed operation using the scheduler
function.
18. The lighting control network of claim 14 wherein each of the
ballasts is to send a report indicating its failure or impending
failure to the lighting control application program.
19. The lighting control network of claim 14 wherein the ballasts
are essentially replicates from a standpoint of hardware.
20. The lighting control network of claim 14 wherein each of the
ballasts integrates in its enclosure a scheduler function, and
wherein timed operation the ballast using the scheduler function is
set in the graphical user interface.
Description
[0001] This application is a continuation of Ser. No. 10/975,203,
filed Oct. 27, 2004, entitled "Electronic Lighting Ballast", which
is a non-provisional application that claims the benefit of the
earlier filing date of U.S. Provisional Application Ser. Nos.
60/516,036 filed Oct. 30, 2003, and 60/603,406 filed Aug. 20,
2004.
[0002] An embodiment of the invention is related to a lighting
control system that uses intelligent power switching elements each
of which can drive any one of a variety of electric discharge lamps
at different output wattages and different input voltages, with
lamp control functions such as dimming and timer being integrated
into each element. Other embodiments are also described.
BACKGROUND
[0003] Ballasts are an integral component of the lighting industry
and are either magnetic or electronic. Magnetic ballasts utilize
components which are heavy and cumbersome, while electronic
ballasts use electric circuits on a light-weight and reduced size
circuit board. A ballast may be used to start a high density
discharge (HID) lamp, and regulates electrical current used by the
lamp. HID lamps are identified by the gas within the lamp--metal
halide (MH), high-pressure sodium (HPS) or mercury vapor (MV)--and
the gas affects the color of the light. Buyers choose a specific
HID lamp based on the color, input voltage, output wattage and the
starter (regular or pulse start).
[0004] There are two categories of HID ballast: magnetic and
electronic. Magnetic ballasts, also called "core and coil"
ballasts, dominate the HID market. Although inexpensive, magnetic
ballasts flicker, are noisy and weigh as much as 86 lbs. Ballast
manufacturers have redesigned their products to reduce electronic
interference and noise, and lamp manufacturers have introduced
pulse-start lamps to shorten the slow start times. Despite these
improvements, magnetic ballasts are still energy-inefficient.
Regulatory actions and fines threatens the long-term outlook for
magnetic ballasts and, as they fail, many are being replaced with
electronic ballasts.
[0005] Electronic ballasts may be 30-50% more energy-efficient than
magnetic ballasts and deliver a relatively non-flickering, silent
light, reduce the problem of magnetic interference, and may weigh
less then 8 lbs. Until now, however, most electronic ballast
manufacturers have followed a short-sighted, one-to-one design
approach, requiring a unique electronic ballast for every input
voltage, output wattage and lamp type combination. As an example, a
400 watt GE lamp works at optimal efficiency generally with only
one particular ballast, whether the ballast is magnetic or
electronic. If the ballast and lamp are not compatible or matched,
the operation of the lamp will not be efficient, thereby adversely
affecting brightness and the life of the lamp. Additionally, in the
case of magnetic ballasts, each ballast has to be specifically
wired for each lamp voltage input, such as 100V, 120V and so forth.
Such wiring is accomplished at the manufacturer's factory or the
end user is required to wire the ballast for each lamp depending on
application. Therefore, a different ballast is required for each
input voltage. These manufacturers often also sell dimmers, timers
and controllers as separate, auxiliary components, to be used with
their particular ballast design.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The embodiments of the invention are illustrated by way of
example and not by way of limitation in the figures of the
accompanying drawings in which like references indicate similar
elements. It should be noted that references to "an" embodiment of
the invention in this disclosure are not necessarily to the same
embodiment, and they mean at least one.
[0007] FIG. 1 shows a single housing or enclosure of an example,
single output lighting ballast.
[0008] FIG. 2 is a block diagram of example electronics that may be
integrated into the lighting ballast enclosure.
[0009] FIG. 3 shows an example "economy version" of the single
output lighting ballast.
[0010] FIG. 4 is a block diagram of example electronics integrated
into the enclosure of the economy version of the ballast.
[0011] FIG. 5 is a circuit schematic of an example boost
converter/power factor circuit and standby power supply/bias
supply.
[0012] FIG. 6 is a circuit schematic of an example buck
converter.
[0013] FIG. 7 is a block diagram of an example inverter.
[0014] FIGS. 8a and 8b are block diagrams of respective lighting
networks that use intelligent power switching elements (IPSEs).
[0015] FIGS. 8c-8f are screen shots of example GUI software that
can be used to remotely control a lighting network of IPSEs.
[0016] FIG. 9 is a block diagram of a larger scale lighting
network.
[0017] FIG. 10 is a block diagram of a dialog box that may be
displayed in a High Level graphical user interface (High Level GUI)
of a larger scale lighting network.
[0018] FIGS. 11 and 12 are screen shots of an example High Level
GUI.
DETAILED DESCRIPTION
[0019] An embodiment of the invention is a ballast or Lighting
Control System (LCS) that represents a one-to-many solution. The
ballast in some embodiments of the invention replaces several
unique HID electronic ballasts, timers, dimmers, on/off switches,
photo sensors, control wires, and controls by a single unit. This
single unit incorporates a variety of functions internally,
eliminating the need to employ several external, or add-on
components. For example, the auxiliary components mentioned above
in the Background section need not be provided separately, because
they have been integrated into a single housing. In another
embodiment, the ballast is a universal solution that can be used in
may different countries due to its wide input voltage capability,
and adjustable output to drive different types of lamps and lamps
from different manufacturers.
[0020] An embodiment of the ballast (also referred to as an
intelligent power switching element, IPSE) may be viewed as an
electronic ballast with a brain. For example, microprocessors and
sensor circuitry may be incorporated inside the ballast enclosure
to create a one-to-many solution that includes many popular,
previously add-on, features, such as a timer, dimmer, photo sensor,
remote control and communications, and other sensors such as for
room occupancy (for dimming during non-use periods) and ambient
light levels (for "daylight harvesting"); and for sensing water
level, water temperature, water movement, and dosing (e.g.,
chemical and water mixtures for treatment of water and feeding
fish. Such other sensors are particularly useful for an aquarium or
agricultural/hydroponic lighting application. The IPSE may thus be
viewed as a fully integrated, intelligent lighting control element
that fits the needs of many applications. An embodiment of the IPSE
is thus believed to address a long-standing need to provide a
universal ballast capable of performing a multiplicity of functions
and performing the work of several ballasts constructed in a single
enclosure of reduced weight and size, replacing the necessity of a
great number of separate ballasts.
[0021] Examples of the different types of electric discharge lamps
that can be driven include high pressure sodium, metal halide,
mercury vapor, which are examples of high intensity discharge
lamps, as well as fluorescent lamps. The ballast may also be
configured to drive either standard ignition or pulse-start lamps.
Furthermore, it may eliminate the need for conversion lamps. The
wide input range or lamp input voltage may preferably be, but is
not limited to be, in the range of approximately 90 VAC to 300 VAC
at 50/60 Hz. For example, the same lighting ballast may be able to
operate at both 110 VAC in U.S.A., as well as 220 VAC in Europe,
without having to perform any rewiring or manual selection.
[0022] Beginning with FIG. 1, a single housing of a single output
lighting ballast 102 is shown. In this embodiment, there is a
single lamp output 104 to drive a single lamp at a time, deriving
power from a power supply input 103 (also referred to as a lamp
input or AC mains input). The enclosure for the ballast 102 may
also have, as depicted in FIG. 1, an on/off manually actuatable
switch 105 that is operatively connected to control the switching
power stages within the enclosure, so as to turn on/turn off the
lamp output. A cable connector 108 may be added to the front panel
as shown, to make a wireline communications connection or link
between a remote machine (not shown) and the ballast. In other
embodiments, the communications link may be in accordance with a
wireless networking standard.
[0023] The embodiment of the ballast 102 depicted in FIG. 1 also
has a display panel 111 installed in the front face of the
enclosure as shown, together with a keypad 115. The panel may have
a liquid crystal display (LCD) screen that can show multiple lines
of text/alphanumeric messages, used to display the current status
of operation of the ballast 102, to control the selections for
configuring the ballast, and, in some embodiments, to display
diagnostic information such as that collected by the ballast
itself. The keypad 115 allows a human user to manually navigate a
menu hierarchy that may be shown on the display panel 111, to
change or verify the status of the ballast, make selections
regarding mode of operation (pre-select the lamp manufacturer, lamp
type, and/or lamp wattage), and navigate through diagnostic
information. The keypad 115 may be a four direction, joystick-type
device with a center select button, for example, that allows the
user to navigate in four different directions on the display panel
and then select the desired menu item. Although shown as being
installed on the same face of the enclosure as the one containing
the lamp output and lamp input, alternative locations for the
display panel and/or keypad on other faces of the enclosure are, of
course, possible.
[0024] Referring now to FIG. 2, a block diagram of example
electronics that may be integrated into the enclosure of FIG. 1 is
shown. Power from the lamp input of the ballast is fed, in this
example, through an electromagnetic interference (EMI) filter 226.
The EMI filter helps decrease unwanted noise that originates from
the ballast and may otherwise be injected into the mains. This
noise level may be decreased down to a level that is required by a
government agency for conductive EMI in the, for example, 450
KHz-30 MHz range. As an additional option, an input circuit (not
shown) that provides over voltage and over current protection may
be added in front of the EMI filter, between the filter and the
mains input.
[0025] Power from the lamp input is fed eventually to a boost
converter 204 that provides a regulated DC voltage at its output.
The boost converter 204 includes feedback control to provide the
regulated output, based on a wide range of, in this example, AC
input voltages. The converter can automatically detect and adjust
for the wide range, maintaining a constant output. For example, the
boost converter 204 provides a fixed regulated output for an input
that lies between 100 and 200 volts AC, as well as one that lies
between 200 and 300 volts AC (rms), without requiring any rewiring
of the ballast for the different input voltages. The boost
converter 204 should preferably provide for power factor
correction, when used with residential and commercial AC mains as
the lamp input. In one embodiment, the boost converter converts an
input that is in the range of 100 VAC-300 VAC to 425 VDC regulated.
The latter is selected in view of the greatest AC voltage needed to
turn on a discharge lamp, at the lamp output 104.
[0026] The boost converter 204 may be part of a power factor
correction circuit that helps make more efficient use of the power
that is available from AC power lines. As an example, the power
factor correction circuit may use the L4981A power factor corrector
integrated circuit by STMicroelectronics as the switch mode power
supply controller. Such a circuit will operate to bring its output
voltage up to, in this example, 425 VDC, and maintain this level
constant despite variations in the input. The L4981A power factor
corrector operates, for example, at a frequency close to 100 KHz
and has adjustable duty cycle, where this duty cycle is controlled
in an automatic feedback loop to maintain the output at the
predefined constant DC voltage. A block diagram of the boost
converter 204 that may be implemented using such a power factor
corrector circuit is shown in FIG. 5. Other topologies for
obtaining a conversion from AC mains to regulated DC output are
possible.
[0027] Referring back to FIG. 2, the control electronics including,
in this case, the programmable microprocessor control circuitry 210
will need a power supply voltage to be referred to as Vcc. This may
be provided by a standby power supply 212 that takes power from the
same AC input, through the EMI filter 226. Although different ways
of obtaining such a power supply are possible, FIG. 5 illustrates a
particularly efficient technique that shares some of the circuitry
of the boost converter 204. As seen in FIG. 5, since the output of
the boost converter 204 is a constant, regulated DC voltage V_out,
a transformer 505 may be used, instead of a plain inductor in the
boost converter 204, to obtain a constant voltage V_bias to serve
as Vcc for the control electronics in the ballast enclosure. The
two secondary windings operate as follows: One of the windings
makes a scaled (N.sub.3/N.sub.1) copy of the input voltage at its
output, while the other makes the same scaled copy of the output
voltage minus the input voltage. Note the input voltage can vary
over a wide range. When the outputs are connected in series,
however, the net voltage that appears at V_bias is scaled copy of
the output voltage without dependence on the input voltage. Thus,
once the boost converter has started up, the bias supply becomes
available. This bias voltage is directly proportional to the output
voltage of the boost converter, which in this case is constant and
regulated. For that reason, no further regulation may be needed for
the output V_bias. Resistors 507 and 509 may be, for example, of
the order of a few ohms, for purposes of limiting the peak charging
current into the capacitors 511 and 512. The voltage V_bias may be
given by the relationship V_bias=V_out (N.sub.3/N.sub.1). Thus, for
V_out of 425 VDC, and desired V_bias of 16 VDC, the turns ratio
N.sub.3/N.sub.1 may be about 38/1000.
[0028] The output of the boost converter 204 is fed to a buck
converter 206 whose basic topology is depicted in FIG. 6. The
latter is an example of an adjustable, step down switching voltage
regulator that is to be used to receive a regulated DC voltage and
in response provide adjustable, regulated DC voltage at its output.
For example, the buck converter 206 may be designed to receive 425
VDC and provide an adjustable output of 180 VDC to 400 VDC. As an
example, the buck converter may use a pulse width modulation (PWM)
controller integrated circuit having reference number LM3524DMX by
National Semiconductor, together with an appropriate power stage.
Such a controller continuously compares the output voltage to a
reference DC voltage, and adjusts the duty cycle of the switching
of the power stage. In addition, the output voltage may be
increased or decreased by writing different values (digital codes)
into a digital potentiometer (not shown) such as the AD5262BRU20
integrated circuit by Analog Devices. The switching power supply
topology of a buck converter is preferred due to its power
efficiency and flexible operation, although other types of step
down switching voltage regulators may alternatively be used.
[0029] The output of the buck converter 206 feeds an inverter 208
whose output is to feed a lamp output of the ballast 102. (A noise
filter (not shown) may be interposed between the buck converter and
the inverter, to suppress unwanted switching noise generated by the
inverter). The inverter 208 may incorporate switching power supply
circuitry that generates a relatively high frequency AC
voltage/current waveform needed to efficiently ignite and then
drive various electric discharge lamps. A block diagram of an
example inverter 207 is shown in FIG. 7. The inverter may be
implemented using an L6598 resonant controller from
STMicroelectronics with a half-bridge power stage and an LC output
network. The L6598D is the controller part of the inverter and
includes a voltage controlled oscillator (VCO), control logic, and
driving logic for the half-bridge power stage. The controller
allows a change to the frequency of the VCO via its F-CTRL input.
The inverter output current will in turn depend on the VCO's
operating frequency, where a larger frequency may be used to yield
lower output current. The modulation level input (the MOD input of
the L6598D) may be used to suppress acoustic resonance. As to the
power stage, a pair of pull up and pull down power field effect
transistors may be switched on and off by the controller, to
achieve the desired output waveform. Other types of power stages
are also possible.
[0030] Still referring to FIG. 2, the lighting ballast may also
include control circuitry in the form of, in this example,
programmable microprocessor control circuitry 210 that can command
a change in one or more operating parameters of the buck converter
206 and the inverter 208. More generally, the control circuitry is
provided to change one or more of the operating parameters, to meet
the electrical current, voltage, and/or power requirements of the
lamp load that is connected. For example, to ignite the lamp, the
inverter is commanded to generate a relatively high frequency
waveform that is initially very close to the resonant frequency of
a resonant tank circuit. This resonant tank circuit may be formed
by the combination of the lamp and an LC circuit. When the lamp has
not yet been ignited, and is relatively cold, it presents a
relatively high resistance such that the tank circuit will exhibit
pure or undamped resonance. The output voltage generated by the
inverter power stage is thus magnified across the lamp; this effect
is also referred to as a strike.
[0031] As the lamp ignites, its resistance drops and the lamp heats
up precipitously, so that the resonance effect essentially
disappears. At that point, the inverter may be commanded to sustain
the rated or nominal drive current specified for the particular
lamp, at a much lower voltage. The controller of the inverter
should thus be designed with the appropriate sensing elements that
sense, for example, output current and/or voltage across the lamp,
so as to maintain the correct current by changing the output
voltage across the lamp. This may be achieved by adjusting the
operating frequency and/or duty cycle of the switch mode power
supply circuitry in the inverter power stage, as part of an
automatic feedback control loop. Other switch mode power supply
control methods may alternatively be used, to achieve the desired
electrical waveform at the output.
[0032] Because the lamp resistance is relatively low once the lamp
is ignited and warmed up, the initial settings for the operating
parameters of the power stage, including, for example, the
operating frequency and the input voltage to the inverter 208
(achieved in this example by adjusting the output voltage of the
buck converter 206), should be carefully constrained to avoid
burning out the lamp due to an over current condition.
Integrated Lamp Functions
[0033] The control circuitry that is installed in a ballast
enclosure may be based on one or more microcontrollers that are
executing firmware which allows one or more of a number of lamp
functions to be implemented. These functions include timer and
scheduling (turn on and turn off of the lamp output at certain
times of the day for certain durations), dimming, measurement of
the temperature in the circuit boards and power stages of the
ballast, output current and lamp voltage measurement, lamp
selection (including type, manufacture, and/or wattage), as well as
detection of ignition and fault conditions. A microcontroller may
also be used to interact with the user either through a local
interface on the enclosure, or through a remote graphical user
interface (see Lighting Network Functions below). For example, a
micro controller such as ATMEGA8-16AI integrated circuit by ATMEL
may be installed in the enclosure and that is coupled to scan the
keypad 115, manage the display panel 111, and exchange data
relating to the user selections, or to any other item to displayed,
with a central processing unit (CPU). The CPU may be a separate
microcontroller, such as an ATMEGA32-16AI integrated circuit by
ATMEL that executes firmware to implement the lamp operation
functions described above. An example implementation of these
functions, that have been integrated into the single ballast, are
as follows.
[0034] The control electronics that is installed in the enclosure
(e.g., the microcontroller and associated attendant circuitry) may
be coupled to control the inverter and to receive a selection of
lamp load type, so that the same lamp output can alternatively
drive a high pressure sodium lamp and a metal halide lamp, for
example, without requiring a separate inverter. The microcontroller
thus controls the power switching stages so that the single lamp
output can drive each of the different types of lamps in an
efficient manner, to not adversely affect brightness and the life
of each lamp. In another embodiment, the ballast may be designed so
that the different lamp types that can be driven by the same output
include a high pressure sodium, a metal halide, and a mercury vapor
lamp. The "mapping" between each type of lamp and the commands
needed to configure the switching power stages may be described as
follows. Responding to queries on the digital display located on
the ballast enclosure, the user selects, using the keypad buttons,
between the alternatives programmed into the firmware with a
designation of lamp type, lamp wattage, and lamp manufacturer. As
an alternative, the user choices of lamp type, lamp wattage, and
lamp manufacturer may be indicated by setting DIP switches (not
shown) within the ballast enclosure.
[0035] A lamp turn on procedure may be as follows. Upon power up of
the control circuitry in the ballast, the type of lamp to be driven
is first determined (e.g., by reading a switch setting or menu
selection that has been made by the user either locally or
remotely). Next, the following turn on sequence for the power
switching stages is observed: first, the buck converter is
initiated, followed by the power factor correction/boost converter
circuit, and then the inverter stage. This is because the power
factor correction circuit may have some difficulty starting up
without a load. A fixed or electronically adjustable preload can
alternatively be used to accomplish the proper startup of the boost
PFC, but the sequencing described above provides a more efficient
and cost effective method. The initial settings will be designed to
drive the particular type of lamp that has been selected, at its
nominal power rating, e.g. maximum brightness. Once the lamp has
warmed up and is being driven, a dimmer level is obtained by the
control electronics (e.g., by reading a dimmer switch setting or
menu selection). The desired dimming level is then obtained by
commanding a change to or adjusting the input voltage to the
inverter. In the embodiment depicted in FIG. 2, this is achieved by
commanding the buck converter 206 to reduce its output voltage. A
number of predefined dimmer levels may be mapped to corresponding
inverter input voltage and inverter operating frequency, for each
type of lamp.
[0036] In addition to, or as an alternative to, the ability to
select the type of lamp to be driven by a given lamp output,
another embodiment of the invention has the needed control logic to
control, for example, the inverter, so that various
manufacturer-specific lamps of various wattages can be driven by
the same lamp output. Thus, referring back to FIG. 2, the enclosure
of the single ballast 102 may include in addition, or as an
alternative to, the lamp load type selector 216, a lighting
manufacturer selector 220, which provides a selection by the user
to the programmable microprocessor control circuitry 210. The
programmable microprocessor may then access a predefined lookup
table, for example, for the particular combination of lamp load
type and/or lighting manufacturer, as well as rated lamp wattage
selection (received from a separate wattage selector 218) to
determine which operating parameters of the buck converter and/or
inverter to change so as to appropriately ignite and drive the lamp
that will be connected.
[0037] In the embodiments of the invention illustrated in FIGS. 2
and 4, there are two types of user interfaces that are installed
within the enclosure of the ballast and that allow a user to
manually select a setting for the lamp to be driven. In the version
depicted in FIG. 1, this user interface includes the display panel
111 and keypad 115. In contrast, the version depicted in FIG. 3 is
an economy version in which a, for example, rotary multi-position
switch S1, S2, or S3 is installed in the enclosure, for the user to
make his/her selections. As an alternative or as an addition to a
rotary switch, a DIP switch may be installed in the enclosure to
perform the same selection. In the economy version, programmable
microprocessor control may not be needed due to the reduced
functionality (e.g., no network communications capability), and
instead suitable control logic 310 may be provided to translate the
combination of lamp selections into the needed commands for
configuring operation of the buck converter 206 and inverter 208.
The control logic 310 may also be designed to receive a dimmer
level through a dimmer selector (not shown), and in response
configure the power switching stages appropriately to achieve the
desired dimming level.
[0038] It should be noted that in some embodiments, such as
ballasts for driving HID lamps, the microprocessor control
circuitry will start a timer (e.g., 15 minutes) after initially
enabling the lamp output to drive the lamp, which disables the
dimming function until a predetermined interval of time has elapsed
with the lamp on.
[0039] It should be noted that with respect to the dimming
function, many high intensity discharge lamps are not actually
designed to be dimmed, and are typically only operated at their
maximum rated brightness. In such cases, the dimming function
provided here may reduce the luminosity by no more than fifty
percent or to another pre-determined level, in contrast to
conventional incandescent dimming capabilities which can reduce
luminosity continuously down to essentially zero percent.
Integrated Lighting Network Functions
[0040] Returning to FIG. 1, this embodiment of the lighting ballast
is also capable of acting effectively as an end node in a lighting
network, via a remote interrogation communication network interface
214. As an example, an RS485 communication port may be built into
the enclosure and coupled to the programmable microprocessor
control circuitry 210, to allow a graphic user interface to
remotely program the ballast. Thus, for example, changes to the
lamp output characteristics of hundreds or even thousands of lamps
may be effected in real-time, via a remote location such as the
office of the facilities manger of a commercial building or
agricultural farm. More generally, and referring now to FIGS. 8a
and 8b, the network interface 214 allows the individual ballast
102_ to be part of a lighting network that has a large number of
different types of lamps 804, 806, and 810, for example, that can
be controlled via a central office or location having a remote
central machine 814. The machine 814 may be a personal computer
running lighting control and management software. There may also be
a signal converter 816, and in some embodiments, one or more signal
repeaters 818. The communication link 820 may be wireline or
wireless between each ballast 102 and the machine 814. The machine
814 may be a hub in a multi-layered, hierarchical network (e.g.,
FIG. 8b). The graphical user interface may be running in a master
control device that communicates with the remote central machine
814; the master control device may be a mobile handset, personal
digital assistant (PDA), notebook computer, or a more traditional
desktop unit that is running lighting control and management
software (see FIGS. 9-11 described below).
[0041] Communications directed at a lighting ballast may include a
command or request to turn on/turn off an output, set output
characteristics required by a particular type, wattage, or
manufacture of lamp, engage a dimming function, set a timer to turn
on or turn off an output after a given time interval has elapsed,
and implement daytime power savings by turning off an output
without the need for a photocell to be installed near the lamp or
the lighting ballast.
[0042] In addition to the communications directed at a lighting
ballast, the lighting ballast 102 by virtue of its programmable
microprocessor may actually initiate a command or request in the
direction of the central, remote machine 814. For example, the
ballast may transmit a report of its operation periodically,
including burn hour updates as well as indicating a failure or
impending failure of its respective lamp. This is an example of a
lighting ballast in which its integrated control electronics is
programmable to provide real-time diagnostics that may be sent to a
central location for processing, or they may be displayed locally
at a display panel of the ballast. The latter is an example of the
ballast being used as a stand-alone unit, where a user configures
an output of the ballast using the integrated display panel and
keypad, and the display panel is used to show monitored burn hours,
thermal output, and efficiency which may be computed under
microprocessor control.
[0043] FIGS. 8c-8f show screen shots of an example, remote
graphical user interface (GUI) with dialog boxes or windows, that
may be used to manage the lighting network. The ballasts, also
referred to here as devices, may be displayed as grouped under
their specific physical locations such as Office, Floor, or Room
(e.g., FIG. 8c). Lamp intensity (dimming; on/off state) may be
controlled from the GUI (individually, FIG. 8d; and/or on a per
zone basis, e.g. FIG. 8e). Historical operating information that
has been collected about each device is stored in a database and
may be viewed via a separate window (e.g., FIG. 8f).
[0044] Turning now to FIG. 9, a block diagram of another type of
lighting network is shown that uses network-ready ballast 102 to
provide a flexible lighting application. In this type of lighting
network, which is also referred to as a larger scale lighting data
collection system or network, there may be three items of
software/hardware. There is a server 904, a Type 1 client 908, and
a Type 2 client 910. The server 904 may be a machine that is
running an application program that provides data collection
services, and may provide long term data storage such as in a hard
disk drive. The server 904 may also perform the following tasks.
First, it may serve to connect and disconnect to a client
application (Type 1 or Type 2), via a network, such as the
Internet. In addition, the server may receive data from all Type 1
clients that are connected to it, and may periodically store the
data, for example, in a database. This periodic storage may occur,
for example, every hour or every minute. The server 904 may also
respond to requests from Type 2 clients 910. Such a response may
include sending data from the database.
[0045] Turning now to the Type 1 client 908, this may be a
combination of an application program running on a machine, so as
to control the operation of a number of ballasts 102. There may be
many Type 1 clients 908 in the network. Each Type 1 client 908 may
be a fixed client station (e.g., remote central machine 814, see
FIG. 8a) which may be situated near one or more ballasts 102, in
different places over a relatively wide geographic range.
[0046] As to a Type 2 client 910, this may be a combination of an
application program running on a machine, which allows a user to
reach the contents of the server-side databases, via, for example,
the Internet. The Type 2 clients 910 may be distant client stations
(including, for example, portable notebook computers) which may be
situated essentially anywhere that there is Internet access.
[0047] Turning now to FIG. 10, a block diagram of a dialog box that
may be displayed in a High Level graphic user interface (High Level
GUI) of a lighting network is shown, and particularly one provided
by the server 904 for managing the lighting network. There is a
window 840, which shows all Type 1 and Type 2 clients that are
connected to the server 904. In window 842, current activity is
depicted, such as data having been received from an active Type 1
client. Such a window may be referred to as a Type 1 client log
window. Similarly, there is another window 844, referred to as a
Type 2 client log window, which shows the activity of Type 2
clients. The window 840 allows a user to search connections to a
client, and to select from them so as to change their
parameters.
[0048] Turning now to FIG. 11, a screen shot of a "server monitor"
program in the High Level GUI is shown which allows a Type 2 client
to inspect the data that has been received from any ballast (via a
Type 1 client), during any particular time interval. The data that
has been reported by the network connected ballast includes, in
this case, energy (e.g., kiloWatthours) used to date, lamp current,
lamp voltage, wattage, mains voltage as measured at the ballast,
PFC voltage, and ballast or lamp temperature. The software may also
provide maintenance reports for lamps--e.g., showing the status of
a lamp, its age, current and/or historical performance, and
previous lamp replacements. The example server monitor window is
divided into generally three areas. There is the site navigation
area 850 which allows the user to choose the site of the Type 1
client through, for example, a dropdown list. This functionality
also allows the user to change the Internet protocol, IP, address
of that site, as well as its name. Once the site has been chosen,
the user may also define the time interval, through date and time
dialog boxes, for ballast information to be retrieved from the
database. Once the choice of site and time interval has been
entered and applied, the user may select a particular lamp at the
inner site navigation area 854. The information that concerns the
selected lamp, for the requested data and time interval, may be
displayed in several graphs as shown, in the area referred to as
the parameters in dynamics area 856. Finally, there may also be an
area 860 that shows the lamp and/or ballast parameters numerically,
for the selected lamp at the exact date and time given in the area
854. Note that zoom functions may be added to expand the scale of
the plots shown in the dynamics area 856.
[0049] In FIG. 12, another example screen shot of the High Level
GUI is shown, where a site navigation dialog box 875 allows a
lighting maintenance engineer to select one of several different
lighting sub-networks of an organization. These sub-networks may be
situated in different cities or countries. A box 877 allows the
engineer to select the date and time intervals to monitor or recall
from storage. A particular unit (multiple ballasts/lamps) in the
given site is selected via folder tab icons 881. Boxes 879 then
show the selected operation parameters of a particular lamp
graphically, while boxes 880 show numerical values for one or more
lamps in the selected unit. Other ways of arranging the graphs and
dialog boxes shown in FIG. 1012 are alternatively possible.
Summary of Software Control Features
[0050] Based on the above discussion, there may be three distinct
forms of software that may be running in an embodiment of the
lighting control system, to control and maintain the system using
the individual ballast/IPSE capabilities described: [0051] Keypad
software--The user switches on and off, changes lamp configuration,
sets timer function, sets dimmer function and monitors lamp
performance, lamp-burn hours and electricity use, all from the
switch, keypad and digital display on the ballast enclosure. This
software may also accept lighting control commands, in some
embodiments, from rotary switches or DIP switches that are on or
within the ballast enclosure. [0052] GUI software--Lamps are
networked via wired or wireless connections of the ballasts, and,
through optional repeaters and/or converters communicate with
lighting control software. This software may be installed on a
personal computer and may be linked via Internet, LAN or other
network to another control unit, such as a PDA, laptop, cell phone
or another personal computer. Thus, a network of individual
ballasts can be controlled in this way. See, e.g. FIGS. 8a-8f.
[0053] High Level GUI software--This software may be used by
lighting maintenance engineers, to monitor and control the
performance of one or more Internet-connected lighting systems with
GUI control. These systems could be scattered around the world,
receiving commands to send data to a central server controlled by
the administrator of the High Level GUI software. This software may
thus control a network of GUI-controlled networks. See, e.g. FIGS.
9-12.
[0054] In all three cases, on-board diagnostics (of the individual
ballast's electronics and lamp) and real-time cost analysis
(determining the cost of operating the lamp based on the historical
data) may be performed in real time. Adjustments to the lamp
operation may then be made to compensate for increased costs, for
example.
Lighting Applications
[0055] When the lamps of a large lighting application are replaced
with, for example, those of a different manufacturer or those of a
different wattage, their individual ballasts need not be physically
replaced, if electronic ballasts such as those described here (also
referred to as IPSEs) are used. Instead, the retrofit occurs by
simply re-configuring or re-programming the IPSEs (via a graphical
user interface running in a master control device, for example) so
that the output ports for the respective lamps provide the
appropriate voltage and power.
[0056] Some or, for very demanding applications, most if not all of
the above lamp functions may be implemented in a single IPSE. In
that case, each function may also be monitored or changed by the
central computer (also referred to as a master control device) on a
per output basis. This capability may help better manage the cost
of lighting in a large-scale lighting environment such as that of a
retail warehouse-type building. For example, the building may have
different retail sections that generate different traffic patterns
during the day. While a few sections are particularly busy in the
morning and hence may need full light, most of the building has
either not been opened to the public or has minimal foot traffic
thereby requiring much less light. Other sections may not need much
light at certain times of the day, e.g. the garden section may have
an open space that receives sun light. The building may
alternatively be a multi-story structure such as a high rise office
building with certain floors or sections of floors that have been
determined to need less light than others. Each floor or section
may be provided with a separate hub. The IPSEs may thus be arranged
in the appropriate hierarchy using hubs, so that the system control
software can be used to dim or even shut off the IPSEs that are in
a given zone, e.g. connected to the same hub. These zones may be
relatively small, e.g. office lighting in a few offices on a single
floor, or they may be relatively large, e.g. all of the street
lamps of an entire city. However, since each ballast/IPSE is
individually programmable over the network, individual lamps may be
independently dimmed or shut off under remote control.
[0057] In many cases, the spatial layout and needed wattage of
lighting is similar from one building to another (e.g., an entity
owns several branches that are laid out in the same manner). In
that case, the control system software settings (including the
programmed operation schedule e.g., on a 24 hours per day, seven
days a week, 365 days per year basis, the "spatial" arrangement,
and the wattage settings for the IPSEs) once they have been
determined for one branch may be simply copied and loaded into the
lighting control system of another branch. This saves the entity a
significant amount of time and expense in configuring its lighting
control system in multiple branches.
[0058] An embodiment of the invention comprises a housing having a
power supply input, and a lamp output to drive a single lamp; and
power switching circuitry, installed in the housing and being
powered through the power supply input, the circuitry having a
plurality of predefined settings that are selectable by a user to
configure the circuitry to drive one of a plurality of different
types of electric discharge lamps at a time, using the lamp output.
The settings may enable high pressure sodium, metal halide, and
mercury vapor high intensity discharge lamps to be driven by the
lamp output. The power switching circuitry may have further
predefined settings to enable lamps of substantially different
wattage capabilities to be driven by the lamp output. The power
switching circuitry may alternatively, or in addition, have
settings that are manually pre-selectable by a user, via a user
interface that is built into the enclosure, to indicate which of a
number of discharge lamps of different manufacturers, that may be
designed for use with different types of ballasts specified by the
manufacturers, to be driven by the lamp output.
[0059] The embodiment of the invention described in the previous
paragraph may be further equipped with a multi-position selector
switch installed on an outside panel of the housing and coupled to
the power switching circuitry, where the user is to select any one
of the predefined settings using the switch. As an alternative, or
in addition, a digital processing section may be installed that is
coupled to control the power switching circuitry, and a digital
display panel and a keypad may be installed on an outside panel of
the housing and coupled to the digital processing section. The user
may then select any one of the predefined settings using the keypad
and obtain information on operating parameters of the apparatus via
the display panel.
[0060] A communication interface may also be coupled to the digital
processing section, to allow the apparatus to be an end node in a
lighting network and allow the user to remotely select any one of
the plurality of predefined settings from a central location in the
network. A master control unit may be provided that is
communicatively coupled to the communication interface in the
lighting network, and has a graphical user interface from which the
user remotely selects any one of the predefined settings for each
of a plurality of end nodes in the network.
[0061] In yet another embodiment of the invention, a further lamp
output may be installed to drive an additional, single lamp.
Further power switching circuitry may be installed in the housing
that is powered through the power supply input to drive the
additional lamp.
[0062] The invention is not limited to the specific embodiments
described above. For example, the voltage and frequency numbers
used to describe operation of the elements of the ballast may only
apply to some, not all, of the different embodiments of the
invention. In another embodiment, the ballast/IPSE may have a
single enclosure that contains two or more "channels" where each
channel includes a single set of the electronic elements shown in
FIG. 2 or FIG. 4. Such multi-output ballast may share the same lamp
input, or it may be powered by separate lamp inputs. Accordingly,
other embodiments are within the scope of the claims.
* * * * *