U.S. patent application number 12/466077 was filed with the patent office on 2010-11-18 for universal lighting source controller with integral power metering.
This patent application is currently assigned to Cooper Technologies Company. Invention is credited to Joe Stelzer, Kenneth Walma.
Application Number | 20100289430 12/466077 |
Document ID | / |
Family ID | 43067958 |
Filed Date | 2010-11-18 |
United States Patent
Application |
20100289430 |
Kind Code |
A1 |
Stelzer; Joe ; et
al. |
November 18, 2010 |
Universal Lighting Source Controller with Integral Power
Metering
Abstract
A universal lighting source controller including integral power
metering for use with substantially all light source types
including fluorescent, incandescent, magnetic low voltage,
electronic low voltage, light emitting diode ("LED"), high density
discharge ("HID"), neon, and cold cathode. The lighting source
controller includes a line voltage dimming circuit that can control
the intensity of light sources in a lighting circuit and measures
the actual amount of power consumed by the light sources. The line
voltage dimming circuit includes a triac circuit for controlling
this intensity and current and voltage detection circuits for
measuring the power consumption. The lighting source controller can
also include low voltage dimming circuits to provide a control
signal to light sources having electronic or magnetic dimming
ballasts to set the intensity of these light sources.
Inventors: |
Stelzer; Joe; (London,
GB) ; Walma; Kenneth; (Peachtree City, GA) |
Correspondence
Address: |
KING & SPALDING, LLP
1100 LOUISIANA ST., STE. 4000, ATTN.: IP Docketing
HOUSTON
TX
77002-5213
US
|
Assignee: |
Cooper Technologies Company
Houston
TX
|
Family ID: |
43067958 |
Appl. No.: |
12/466077 |
Filed: |
May 14, 2009 |
Current U.S.
Class: |
315/307 |
Current CPC
Class: |
H05B 47/165 20200101;
H05B 47/18 20200101; H05B 47/10 20200101 |
Class at
Publication: |
315/307 |
International
Class: |
H05B 37/02 20060101
H05B037/02 |
Claims
1. A lighting control system, comprising: a lighting control
circuit operable to receive a control signal comprising a command
to energize a light source and allow electrical energy to flow to
the light source in response to the command; and a controller
communicably coupled to the lighting control circuit, the
controller operable to transmit the control signal to the control
circuit, wherein the lighting control circuit is electrically
coupled to the light source, and wherein the lighting control
circuit is operable for use with at least two of fluorescent,
incandescent, magnetic low voltage, electronic low voltage, light
emitting diode (LED), high intensity discharge (HID), neon, and
cold cathode light sources.
2. The lighting control system of claim 1, wherein the lighting
control circuit comprises a microprocessor operable to receive the
control signal and transmit an electrical signal allowing the flow
of electrical energy to the light source in response to the
command.
3. The lighting control system of claim 1, wherein the control
signal further comprises an intensity setting for the light
source.
4. The lighting control system of claim 3, wherein the lighting
control circuit adjusts the intensity level of the light source by
sequentially allowing and blocking the flow of electrical energy to
the light source at a frequency.
5. The lighting control system of claim 4, wherein the control
circuit comprises a triac operable to sequentially allow and block
the flow of electrical energy to the light source at the
frequency.
6. The lighting control system of claim 1, wherein the lighting
control circuit further comprises a power metering circuit, wherein
the power metering circuit measures an amount of electrical energy
used by the light source.
7. The lighting control system of claim 6, wherein the power
metering circuit comprises: at least one voltage detection circuit;
and a current measurement circuit.
8. The lighting control system of claim 7, further comprising a
user interface communicably coupled to the controller, wherein the
controller transmits a representation of the amount of electrical
energy used by the light source to the user interface for
outputting to a user.
9. The lighting control system of claim 1, wherein the light source
comprises an electronic dimming ballast.
10. The lighting control system of claim 9, further comprising a
low voltage dimming circuit communicably coupled to the electronic
dimming ballast and operable to transmit a dimming level signal to
the electronic dimming ballast, wherein the command comprises an
intensity setting for the light source and wherein the dimming
level signal corresponds to the intensity setting.
11. The lighting control system of claim 10, wherein the dimming
level signal comprises a variable analog voltage level.
12. The lighting control system of claim 10, wherein the dimming
level signal comprises a digital signal.
13. A lighting circuit control card for use with a plurality of
types of lighting sources, comprising: a control circuit,
electrically coupled to at least one light source, the control
circuit operable to receive a control signal comprising an
indication that the at least one light source should be energized
and operable to permit electrical energy to flow to the at least
one light source in response to the indication; and a power
metering circuit operable to determine an amount of electrical
power consumed by the at least one light source.
14. The lighting circuit control card of claim 13, wherein the
plurality of types of lighting sources comprise at least two of
fluorescent, incandescent, magnetic low voltage, electronic low
voltage, light emitting diode ("LED"), high density discharge
("HID"), neon, and cold cathode light sources.
15. The lighting circuit control card of claim 13, wherein the
power metering circuit comprises: at least one voltage detection
circuit; and a current detection circuit.
16. The lighting circuit control card of claim 13, wherein the
control signal further comprises a desired intensity level and
wherein the control circuit adjusts an intensity level of the at
least one light source based on the desired intensity level.
17. The lighting circuit control card of claim 16, wherein the
control circuit adjusts the intensity level of the at least one
light source by sequentially allowing and blocking the flow of
electrical energy to the at least one lighting source.
18. The lighting circuit control card of claim 17, wherein the
control circuit further comprises a triac, wherein the triac
sequentially allows and blocks the flow of electrical energy to the
at least one light source at a frequency.
19. A method for controlling a light source, the method comprising
the steps of: receiving a control signal at a lighting control
circuit, the control signal comprising a command to energize the
light source and a desired intensity level for the light source; in
response to receiving the control signal, allowing, by the lighting
control circuit, electrical energy to flow to the light source; and
measuring, by the lighting control circuit, an amount of electrical
energy used by the light source, wherein the lighting control
circuit is operable for use with at least two of fluorescent,
incandescent, magnetic low voltage, electronic low voltage, light
emitting diode ("LED"), high density discharge ("HID"), neon, and
cold cathode light sources.
20. The method of claim 19, wherein the step of allowing electrical
energy to flow to the light source comprises sequentially allowing
and blocking the flow of electrical energy to the light source at a
frequency corresponding to the desired intensity level.
21. The method of claim 20, wherein the lighting control circuit
comprises a microprocessor and a triac and wherein the triac
receives a signal from the microprocessor and in response to the
signal, the trial allows electrical energy to flow to the light
source for a period of time corresponding to the frequency.
22. The method of claim 19, further comprising the step of
transmitting a representation of the amount of electrical energy
used by the light source to a user interface for outputting to a
user.
23. The method of claim 19, further comprising the step of
receiving the control signal at a panel controller from a source
external to the panel controller and the lighting control circuit,
wherein the control signal is received from the panel
controller.
24. The method of claim 23, wherein the source external to the
panel controller and the lighting source comprises a building
management system.
25. The method of claim 19, further comprising the step of
receiving configuration information for the lighting control
circuit.
26. The method of claim 25, wherein the configuration information
comprises a high power limit and a low power limit for the lighting
source.
27. A lighting system, comprising: a lighting controller operable
to send control signals to line voltage dimming cards; one or more
line voltage dimming cards communicably coupled to the lighting
controller, each line voltage dimming card comprising: a control
circuit, electrically coupled to a lighting circuit comprising at
least one light source, the control circuit operable to receive a
control signal comprising an indication that the at least one light
source should be energized and a desired intensity level for the at
least one light source, the control circuit further operable to
permit electrical energy to flow to the at least one light source
in response to the indication and control an intensity level of the
at least one light source in response to the desired intensity
level; and a power metering circuit operable to determine an amount
of electrical power consumed by the at least one light source in
the lighting circuit; and a user interface communicably coupled to
the lighting controller and operable to receive configuration
information for the panel controller and the one or more line
voltage dimming cards and further operable to output a
representation of the amount of electrical power consumed by the at
least one light source from the lighting controller, wherein each
of the line voltage dimming cards is operable for use with at least
two of fluorescent, incandescent, magnetic low voltage, electronic
low voltage, light emitting diode ("LED"), high density discharge
("HID"), neon, and cold cathode light sources.
28. The lighting system of claim 27, wherein the lighting
controller is further operable to receive control signals from a
controller via a network.
29. The lighting system of claim 27, further comprising one or more
low voltage dimming cards communicably coupled to the lighting
controller, each line voltage dimming card operable to transmit a
dimming control signal corresponding to the desired intensity level
to a light source having an electronic dimming ballast.
30. The lighting system of claim 27, wherein the control circuit
controls the intensity level of the at least one light source by
energizing and de-energizing the at least one light source at a
frequency corresponding to the desired intensity level.
31. The lighting system of claim 30, wherein the control circuit
comprises a zero cross circuit for timing the energizing and
de-energizing of the at least one light source.
32. The lighting system of claim 27, wherein each of the line
voltage dimming cards is operable for use with each of fluorescent,
incandescent, and LED light sources without modification to any
hardware of the line voltage dimming card.
Description
TECHNICAL FIELD
[0001] The invention relates generally to lighting source
controllers, and more specifically to universal lighting source
controllers having integral power metering.
BACKGROUND
[0002] A lighting source controller is an electronic device used to
control one or more light sources, such as a fluorescent,
incandescent, or light emitting diode (LED) lamp. A lighting source
controller activates a light source based on various conditions
including occupancy, desired use and time of day. A lighting source
controller also controls the intensity of the light source to
provide a dimming effect. One of the benefits of lighting control
is that dimmed light sources consume less energy than lighting at
full load. For this reason, lighting control has been used in
various control schemes to reduce demand during peak energy demand
times or simply to conserve energy on an ongoing basis.
[0003] Some programs supporting energy conservation, such as the
Leader in Energy and Environmental Design (LEED) certification,
require validation and measurement of actual energy usage to prove
the lighting control systems are realizing reduced energy
consumption. To meet this requirement, a separate energy metering
system is typically employed to gather the required data. These
systems are expensive as they require the design, installation, and
maintenance of a second system.
[0004] Therefore, a need currently exists in the art for a lighting
source controller that both controls and measures energy usage of
light sources without the need for a separate energy metering
system.
[0005] Many commercial and industrial buildings utilize more than
one type of light source. For example, some buildings employ
incandescent, fluorescent, and LED lamps, all in the same building.
A conventional lighting source controller typically needs a
separate control circuit or control card for each type of light
source. This leads to higher costs incurred during the design of
the lighting source controller and high maintenance costs for the
lighting system. It also requires keeping more spare controller
cards readily available, in case one of the controller cards needs
replacement. Accordingly, a need also exists in the art for a
lighting source controller circuit or controller card capable of
controlling multiple types of light sources.
SUMMARY
[0006] The universal lighting source controller can include
integral power metering capability for use with substantially all
common types of light sources, including fluorescent, incandescent,
magnetic low voltage, electronic low voltage, light emitting diode
(LED), high-intensity discharge (HID), neon, and cold cathode.
[0007] The lighting source controller typically includes line
voltage dimming cards for controlling and measuring power usage for
a lighting circuit having one or more light sources. For example, a
lighting control panel can include a single controller for the
panel with multiple line voltage dimming cards, each line voltage
dimming card controlling and metering energy usage for a lighting
circuit with one or more lights. The controller can receive
configuration information and control information for each of the
dimming cards and communicate this information to the dimming
cards. The controller can receive the configuration information
from a user interface having a display and input devices. The
controller can also receive control information from the user
interface or from another device connected to the controller via a
network. For example, the controller can be connected to a building
management system via a network, such as Ethernet or RS485. This
building management system can send commands to the controller to
turn lighting circuits on or off and/or set dimming levels for the
light sources in the lighting circuits.
[0008] The line voltage dimming cards can include a dimming circuit
capable of controlling the intensity level for lights connected to
the dimming card. This dimming circuit is universal and can be used
with most common light sources, including fluorescent,
incandescent, magnetic low voltage, electronic low voltage, LED,
HID, neon, and cold cathode. The line voltage dimming card also can
include voltage detection circuitry and current detection
circuitry. A microprocessor in the line voltage dimming card can
receive current and voltage measurements from the current sensor
and voltage detection circuitry respectively and calculate the
power usage of the lighting circuit controlled by the line voltage
dimming card. The microprocessor can then communicate this power
usage information to the controller, which in turn can output the
power usage information on the user interface.
[0009] The lighting source controller can also include low voltage
dimming cards capable of providing a dimming control signal to
light sources having electronic or magnetic dimming ballasts. For
these light sources, a line voltage dimming card can be used to
provide power for the light sources and to measure the power usage
of the light sources, while a low voltage dimming card can be used
to provide the dimming control. The low voltage dimming card can
provide common ballast dimming control signals, including 0-10 VDC,
1-10 VDC, and digital dimming control signals.
[0010] The controller can receive power usage information from each
of the line voltage dimming cards and communicate this information
to the user interface or to a remote computer for display. The
controller can also calculate additional information for display to
a user, such as the amount of power being used for each phase of a
three phase system and the total amount of power consumed for all
circuits connected to the controller.
[0011] These and other aspects, features and embodiments of the
invention will become apparent to a person of ordinary skill in the
art upon consideration of the following detailed description of
illustrated embodiments exemplifying the best mode for carrying out
the invention as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of the exemplary
embodiments of the present invention and the advantages thereof,
reference is now made to the following description, in conjunction
with the accompanying figures briefly described as follows.
[0013] FIG. 1 is a block diagram depicting a universal lighting
source controller having integral power metering in accordance with
one exemplary embodiment of the present invention.
[0014] FIG. 2 is a block diagram depicting a line voltage dimming
card in accordance with one exemplary embodiment of the present
invention.
[0015] FIG. 3 is an electrical circuit diagram depicting a zero
cross circuit and a voltage detection circuit of a line voltage
dimming card in accordance with one exemplary embodiment of the
present invention.
[0016] FIGS. 4A and 4B are electrical circuit diagrams depicting
voltage detection circuits of a line voltage dimming card in
accordance with one exemplary embodiment of the present
invention.
[0017] FIG. 5 is an electrical circuit diagram depicting an analog
amplifier circuit of a line voltage dimming card in accordance with
one exemplary embodiment of the present invention.
[0018] FIG. 6 is an electrical circuit diagram depicting a
microprocessor circuit of a line voltage dimming card in accordance
with one exemplary embodiment of the present invention.
[0019] FIG. 7 is an electrical circuit diagram depicting a surge
protection circuit, a relay, a relay drive circuit, and a dimmer
circuit of a line voltage dimming card in accordance with one
exemplary embodiment of the present invention.
[0020] FIG. 8 is an electrical circuit diagram depicting
communication circuits and optical isolation circuits of a line
voltage dimming card in accordance with one exemplary embodiment of
the present invention.
[0021] FIG. 9 is an electrical circuit diagram depicting a power
supply circuit of a line voltage dimming card in accordance with
one exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0022] The following description of exemplary embodiments refers to
the attached drawings, in which like numerals indicate like
elements throughout the figures. FIG. 1 is a block diagram
depicting an exemplary universal lighting source controller 100
having integral power metering in accordance with one exemplary
embodiment of the present invention. The lighting source controller
100 controls and meters power usage for substantially all types of
light sources, including fluorescent, incandescent, magnetic low
voltage, electronic low voltage, light emitting diode (LED),
high-intensity discharge (HID), neon, and cold cathode.
[0023] In this exemplary embodiment, the lighting source controller
100 includes a panel controller 105 for controlling and metering
the power usage of multiple lighting circuits from a single
lighting panel (not shown). The panel controller 105 is in
electrical communication with a user interface 110, a digital
communications module 115, one or more line voltage dimming cards
130 and one or more low voltage dimming cards 140. The panel
controller 105 also receives power from a power supply 120 and
provides supply power to each of the line voltage dimming cards 130
and each of the low voltage dimming cards 140.
[0024] The panel controller 105 receives input from users and
provides information to users via the user interface 110. The user
interface 110 can be presented on a variety of displays including a
liquid crystal display (LCD), a computer monitor, or a touchscreen.
In certain exemplary embodiments, a user configures the panel
controller 105, the line voltage dimming cards 130, and the low
voltage dimming cards 140 using input devices, such as a pointing
device or keypad coupled to the user interface 110. The user
interface 110 communicates this configuration information to and
receives information from the panel controller 105 via various
interfaces, including, for example, Ethernet, Universal Serial Bus
(USB), and RS485.
[0025] The digital communications module 115 provides for
electrical communication between the panel controller 105 and
various other systems or computers via a network. For example, in
one exemplary embodiment, the digital communications module 115
includes an Ethernet interface that provides control of light
sources from a building management system and provides diagnostics
and monitoring capabilities from a remote computer. Other
non-limiting examples of communication protocols that can be
provided by the digital communications module 115 include RS485 and
DMX512 (e.g. control by entertainment systems) serial communication
protocols.
[0026] The lighting source controller 100 includes any number of
line voltage dimming cards 130 and low voltage dimming cards 140.
Each line voltage dimming card 130 controls and meters the power
usage of a lighting circuit having one or more light sources. The
line voltage dimming cards 130 are universal and are used with
various types of light sources, including fluorescent,
incandescent, magnetic low voltage, electronic low voltage, LED,
HID, neon, and cold cathode. For example, the same line voltage
dimming card 130 can be removed from a lighting circuit of
incandescent lights and installed in a lighting circuit of
fluorescent lights without any hardware modifications.
[0027] The line voltage dimming cards 130 receive configuration and
control information from the panel controller 105 and provide the
panel controller 105 with the power usage information for its
lighting circuit. In one exemplary embodiment, the configuration
information varies based on the lighting supply power and desired
control scheme and includes parameters such as a high power limit,
low power limit, a setting for turning the lighting source off when
input power is below the low power limit or stay on at low limit,
and a setting for transient response between the high and low power
limits, such as linear, square law, or switched only. The
configuration information also includes a setting for scaling the
transient response based on the high and low power limits. In one
exemplary embodiment, these parameters are received from a user via
the user interface 110. Alternatively, the configuration
information is received from a remote computer via the digital
communications module 115.
[0028] A user programs the panel controller 105 to communicate with
the line voltage dimming cards 130 to activate a lighting circuit
and control the intensity or dimming of the light sources in the
circuit based on various factors, including time of day, occupation
of area, desired use, and amount of lighting present in the area.
Alternatively, the panel controller 105 receives control
information from an outside source, such as a building management
system or an entertainment system.
[0029] As discussed in more detail below with reference to FIG. 2,
each line voltage dimming card 130 includes a microprocessor for
controlling the light sources for its respective lighting circuit.
The microprocessor also receives power usage information for the
lighting circuit provided by one or more voltage detection circuits
and a current detection circuit. This power usage information is
communicated to the panel controller 105 and outputted at the user
interface 110 and optionally at a remote computer via the digital
communications module 115.
[0030] The low voltage dimming cards 140 provide a dimming control
signal to light sources having an electronic or magnetic dimming
ballast. Examples of light sources having electronic dimming
ballasts include analog fluorescent (2, 3, or 4-wire), LED, and HID
dimmable loads. Typically, these electronic dimming ballasts
control the intensity level of a light source based on an analog
voltage or current range, such as a 0-10 VDC input signal.
Additionally, some electronic dimming ballasts control the
intensity level of the light source based on a digital signal. The
low voltage dimming cards 140 provide either an analog or digital
dimming control signal to the light sources in a lighting
circuit.
[0031] Similar to the line voltage dimming cards 130, the low
voltage dimming cards 140 receive configuration and control
information from the panel controller 105. The configuration
information for the low voltage dimming cards 140 varies based on
the type of ballast and control scheme and includes parameters such
as a low voltage high end limit (e.g. 10 VDC), a low voltage low
end limit (e.g. 0 VDC), a setting for coordinating the low voltage
limit and power switching (e.g. always energized or turn off below
low end limit), and a setting for the direction of the low voltage
control (i.e. proportional or inverse). Additionally, in certain
exemplary embodiments, the configuration information also includes
a setting for transient response between the low voltage limits,
such as linear, square law, or switched only, and a setting for
scaling the transient response according to the high end and low
end voltage limits.
[0032] A user programs the panel controller 105 to communicate with
the low voltage dimming cards 140 to control the intensity or
dimming of the light sources in the circuit based on various
factors, including time of day, occupation of area, desired use of
the area, and amount of lighting present in the area.
Alternatively, the low voltage dimming cards 140 receive control
information from an outside source, such as a building management
system or an entertainment system as discussed above. In one
exemplary embodiment, the low voltage dimming cards output a
dimming control signal, such as 0-10 VDC, to a lighting circuit
based on the desired dimming level.
[0033] The exemplary lighting source controller 100 includes a
corresponding line voltage dimming card 130 for each low voltage
dimming card 140 used to control light sources having electronic or
magnetic dimming ballasts. The corresponding line voltage dimming
card 130 provides power for and measures power usage of the light
sources, while the low voltage diming card 140 provides a dimming
control signal for adjusting the intensity of the light
sources.
[0034] FIG. 2 is a block diagram depicting a line voltage dimming
card 130 in accordance with one exemplary embodiment of the present
invention. This exemplary line voltage dimming card 130 includes a
microprocessor 205 and circuitry for activating, dimming, and
measuring power usage of a lighting circuit having one or more
light sources. The circuits of the line voltage dimming card 130
are discussed below with reference to FIG. 2 and an exemplary
circuit diagram for each circuit is also discussed below with
reference to FIGS. 3-9. It should be noted that these circuit
diagrams are exemplary and can be modified without departing from
the scope and spirit of the invention. It should also be noted that
the values for the components in each of the circuit diagrams are
also exemplary and can be modified and in some cases, the
components can be removed or other components added without
departing from the scope or spirit of the invention.
[0035] Referring to FIGS. 1 and 2, the microprocessor 205 receives
power from the panel controller 105 via a transformer 215 and a
power supply 217. The transformer 215 adjusts the voltage level of
the input power and the power supply 217 converts the input
alternating current (AC) power into direct current (DC) power and
provides a steady DC voltage to the microprocessor 205.
[0036] The microprocessor 205 also receives configuration and
control information from the panel controller 105 as described
above with reference to FIG. 1. In this exemplary embodiment, the
panel controller 105 communicates this information to the
microprocessor 205 via a serial communications circuit 212,
although many other communication protocols are possible as would
be known to one or ordinary skill in the art having the benefit of
this disclosure. The microprocessor 205 also utilizes this serial
communications circuit 212 to send the panel controller 105
information including power usage information for the lighting
circuit that the line control dimming card 130 is controlling. The
serial communications circuit 212 and the microprocessor 205 are
electrically isolated from the panel controller 105 by an optical
isolation circuit 210.
[0037] The line voltage dimming control card 130 receives power for
its lighting circuit from a hot power line 221 and a neutral power
line 222 and outputs power onto three separate power lines, a live
power line 280, a switched power line 285 and a dimmed power line
290 depending on the configuration of the lighting circuit. For
example, if light dimming is not desired, the line voltage dimming
card 130 is used to switch the light sources on and off. In this
example, the lighting circuit is connected to the switched power
line 285. If dimming is desired, the lighting circuit is connected
to the dimmed power line 290. Additionally, the live voltage power
line 280 is provided for an emergency non-switched lighting
connection.
[0038] The line voltage dimming card 130 includes a surge
protection circuit 225 for diverting or suppressing a spike in
input voltage. In one exemplary embodiment, the surge protection
circuit 225 is positioned near the entry point of the input voltage
to protect other circuits in the line voltage dimming card 130.
Various types of surge protection circuits 225 can be used with the
line voltage dimming card 130, including metal oxide varistor
circuits and suppression diode circuits.
[0039] The line voltage dimming card 130 also includes a zero cross
circuit 230 for detecting transitions between positive and negative
voltage levels of the input AC voltage. At each transition, the
zero cross circuit 230 provides a short electrical pulse to the
microprocessor 205. This series of pulses resembles a square wave
signal which is used by the microprocessor 205 to time the
energizing and de-energizing of the light sources in a dimming
application.
[0040] A current sensor 235 and an analog amplifier 237 are
provided with the line voltage dimming card 130 to measure the
current flow through the line voltage dimming card 130 and thus,
through the lighting circuit it controls. This current measurement
is taken along the hot power line 221 and is provided to the
microprocessor 205.
[0041] This exemplary line voltage dimming card 130 also includes
three separate voltage detection circuits 240, 250, 260. The
voltage detection circuit 240 measures the voltage level across the
live voltage point 280 and the neutral power line 222. The voltage
detection circuit 250 measures the switched output voltage level
across the switched point 285 and the neutral power line 222
downstream from a relay 247. The voltage detection circuit 260
measures the dimmed voltage level across the dimmed point 290 and
the neutral power line 222. In one exemplary embodiment, each
voltage detection circuit 240, 250, 260 provides the microprocessor
205 with its respective voltage measurement.
[0042] The microprocessor 205 determines the amount of power that
its lighting circuit is consuming using the current measurement
provided by the current sensor 235 and a voltage measurement from
one of the voltage detection circuits 240, 250, 260 depending on
the configuration or application of the line voltage dimming card
130. For example, if the line voltage dimming card 130 is used in a
dimming application, the microprocessor 205 uses the voltage
measurement from the voltage detection circuit 260. In an
alternative exemplary embodiment when the line voltage dimming card
130 is used in a switched (non-dimming) application, the voltage
measurement from the voltage detection circuit 250 is used.
Additionally, in emergency lighting applications, the voltage
measurement from the voltage detection circuit 240 is used. The
microprocessor 205 communicates this power calculation to the panel
controller 105 for display at the user interface 110 or at a remote
computer via the digital communications module 115.
[0043] The line voltage dimming card 130 includes a relay 247 for
passing or blocking electrical power along the hot power line 221
to the light sources of the lighting circuit. The microprocessor
205 activates the relay 247 to energize the lighting loads by
sending a control signal to a relay drive 245, which in turn
energizes a coil in the relay 247. Although a relay 247 is utilized
in this exemplary embodiment, other suitable switching devices can
be used as would be known by one of ordinary skill in the art
having the benefit of the present disclosure.
[0044] The line voltage dimming card 130 also includes a dimming
circuit having a dimmer 257, a dimmer drive 255, and an inductor
265. In one exemplary embodiment, for light sources that do not
have an electronic or magnetic dimming ballast, the microprocessor
205 sends electrical signals to the dimmer drive 255, which in
turn, controls the dimmer to provide a dimming level to light
sources based on control information received from the panel
controller 105. As discussed in more detail below with reference to
FIG. 7, the dimmer 257 includes a triac that is activated and
deactivated at high frequencies to turn the light sources on and
off at a high frequency. This reduces the total amount of energy
delivered to the light sources and therefore, reduces the intensity
of the light. This dimming level is adjusted by changing the
frequency of the activation of the triac in the dimmer 257. In one
exemplary embodiment, the timing of the activation and deactivation
of the triac is synchronized with the zero cross signal by the
microprocessor 205.
[0045] FIG. 3 is an electrical circuit diagram depicting an
exemplary zero cross circuit 230 and an exemplary voltage detection
circuit 240 of a line voltage dimming card 130 in accordance with
the exemplary embodiment of FIG. 2. An operational amplifier
("op-amp") IC1A receives AC voltage across the hot 221 and neutral
222 lines of a lighting circuit and provides a scaled AC signal to
the zero cross circuit 230 and the voltage detection circuit 240.
In this exemplary embodiment, the op-amp IC1A and its associated
circuitry works to scale the input AC signal to an output range of
0-5 VAC. A reference voltage REF_V of 2.5 VAC is provided at the
non-inverting input of the op-amp IC1A to provide a bias voltage at
the midrange of the scaled output range.
[0046] The zero cross circuit 230 converts the AC signal to a
square-wave signal PROC_SQ with peaks corresponding to transitions
of the AC signal through zero volts. This square wave signal
PROC_SQ is transferred to an input of the microprocessor 205 for
use in timing the activation and deactivation of light sources in a
dimming application. This exemplary zero cross circuit 230 includes
an op-amp IC1B, two inverting Schmitt triggers IC2A, IC2B connected
in series at the output of the op-amp IC1B, and associated
resistors and capacitors. Exemplary values for the components of
the zero-cross circuit 230 and for components associated with
op-amp IC1A are listed below in Table 1.
TABLE-US-00001 TABLE 1 Exemplary Component Values for the Zero
Cross Circuit 230 and Components Associated with Op-Amp IC1A
Circuit Component Value R1 4.7 k.OMEGA. R2 990 k.OMEGA. R3 990
k.OMEGA. R4 4.7 k.OMEGA. R5 100 k.OMEGA. R6 1 M.OMEGA. R7 10
k.OMEGA.
[0047] The voltage detection circuit 240 scales the AC signal
received from the op-amp IC1A and provides this scaled signal
PROC_LIVE to the microprocessor 205. The microprocessor 205 can
then compare this scaled signal PROC_LIVE to a reference voltage to
calculate the actual voltage between the live output power line 280
and the neutral power line 222. This exemplary voltage detection
circuit 240 includes an op-amp IC1D, and associated resistors and
capacitors. The voltage detection circuit 240 also includes a
network of diodes and capacitors at the output of the op-amp IC1D
for protecting the microprocessor 205 from voltage ranges above or
below the scaled range of 0-5 VAC. Exemplary values for the
components of the voltage detection circuit 240 are listed below in
Table 2.
TABLE-US-00002 TABLE 2 Exemplary Component Values for the Voltage
Detection Circuit 240 Circuit Component Value R8 39 k.OMEGA. R9 82
k.OMEGA. R10 1 k.OMEGA. R11 100 k.OMEGA. C1 1 nF C2 1 nF C3 100
nF
[0048] FIGS. 4A and 4B, collectively FIG. 4, are electrical circuit
diagrams depicting exemplary voltage detection circuits 250, 260 of
a line voltage dimming card 130 in accordance with the exemplary
embodiment of FIG. 2. Referring to FIG. 4A, the voltage detection
circuit 250 scales the AC signal received across the switched
output power line 285 and the neutral power line 222 and provides
this scaled signal PROC_SWITCHED to the microprocessor 205. The
microprocessor 205 compares this scaled signal PROC_SWITCHED to a
reference voltage to determine the actual voltage between the
switched output power line 285 and the neutral power line 222. This
exemplary voltage detection circuit 250 includes an op-amp IC3A,
and associated resistors and capacitors. The voltage detection
circuit 250 also includes a network of diodes and capacitors at the
output of the op-amp IC3A for protecting the microprocessor 205
from voltage ranges above or below the scaled range of 0-5 VAC.
Exemplary values for the components of the voltage detection
circuit 250 are listed below in Table 3.
TABLE-US-00003 TABLE 3 Exemplary Component Values for the Voltage
Detection Circuit 250 Circuit Component Value R1 4.7 k.OMEGA. R2
990 k.OMEGA. R3 990 k.OMEGA. R4 1 k.OMEGA. R5 4.7 k.OMEGA. C1 100
nF
[0049] Referring to FIG. 4B, the exemplary voltage detection
circuit 260 scales the AC signal received across the dimmed output
power line 290 and the neutral power line 222 and provides this
scaled signal PROC_DIMMED to the microprocessor 205. The
microprocessor 205 compares this scaled signal PROC_DIMMED to a
reference voltage to calculate the actual voltage between the
dimmed output power line 290 and the neutral power line 222. This
exemplary voltage detection circuit 260 includes an op-amp IC3B,
and associated resistors and capacitors. The voltage detection
circuit 260 also includes a network of diodes and capacitors at the
output of the op-amp IC3B for protecting the microprocessor 205
from voltage ranges above or below the scaled range of 0-5 VAC.
Exemplary values for the components of the voltage detection
circuit 260 are listed below in Table 4.
TABLE-US-00004 TABLE 4 Exemplary Component Values for the Voltage
Detection Circuit 260 Circuit Component Value R6 4.7 k.OMEGA. R7
990 k.OMEGA. R8 990 k.OMEGA. R9 1 k.OMEGA. R10 4.7 k.OMEGA. C2 100
nF
[0050] FIG. 5 is an electrical circuit diagram depicting an
exemplary analog amplifier circuit 237 of a line voltage dimming
card 130 in accordance with the exemplary embodiment of FIG. 2.
This exemplary analog amplifier circuit 237 includes an op-amp IC3C
which scales a voltage measurement taken across a current sensing
resistor R44 (See FIG. 7). This voltage measurement is scaled by
the op-amp IC3C and this scaled signal PROC_IM is transmitted to
the microprocessor 205. The microprocessor 205 compares the scaled
signal PROC_IM to a reference voltage to determine the current
flowing through the resistor R44 and thus through the lighting
circuit that the line voltage dimming card 130 controls. Exemplary
values for the components of the analog amplifier circuit 237 are
listed below in Table 5.
TABLE-US-00005 TABLE 5 Exemplary Component Values for the Analog
Amplifier Circuit 237 Circuit Component Value R1 10 k.OMEGA. R2 150
k.OMEGA. R3 1 k.OMEGA. R4 150 k.OMEGA. R5 10 k.OMEGA. C1 100 nF
[0051] FIG. 6 is an electrical circuit diagram depicting an
exemplary microprocessor 205 circuit of a line voltage dimming card
130 in accordance with the exemplary embodiment of FIG. 2. In one
exemplary embodiment, the microprocessor 205 includes 16 pins for
sending or receiving electrical signals. A description of the
signal at each pin of the microprocessor 205 is described below in
Table 6. This exemplary microprocessor 205 circuit includes a light
emitting diode (LED) LD1, a clock circuit 605, and associated
resistors and capacitors. This clock circuit 605 employs a crystal
oscillator X1 to provide a reference clock signal to the
microprocessor 205. Exemplary values for the components of the
microprocessor circuit 205 are listed below in Table 7.
TABLE-US-00006 TABLE 6 Microprocessor 205 Input/Output Pins Pin
Number Description 1 Status indication. 2 Receives voltage
measurement signal PROC_DIMMED from the voltage detection circuit
260. 3 Receives voltage measurement signal PROC_LIVE from the
voltage detection circuit 240. 4 0 V input. 5 +5 V input. 6
Receives square-wave output signal PROC_SC from the zero cross
circuit 230. 7 Not used. 8 Receives clock input signal from
oscillator X1. 9 Receives clock input signal from oscillator X1. 10
Outputs a communication signal to the serial communications circuit
212. 11 Receives a communication signal from the serial
communications circuit 212. 12 Outputs signal to operate the relay
247. 13 Not used. 14 Receives voltage measurement signal PROC_IM
from the analog amplifier circuit 237. 15 Receives voltage
measurement signal PROC_SWITCHED from the voltage detection circuit
250. 16 Sends dimming control signal to the dimmer drive circuit
255.
TABLE-US-00007 TABLE 7 Exemplary Component Values for the
Microprocessor 205 Circuit Circuit Component Value R1 330 .OMEGA.
R2 4.7 M.OMEGA. R3 10 k.OMEGA. C1 22 pF C2 22 pF
[0052] FIG. 7 is an electrical circuit diagram depicting examples
of a surge protection circuit 225, a relay 247, a relay drive
circuit 245, a dimmer drive circuit 255, and a triac dimmer 257 of
a line voltage dimming card 130 in accordance with the exemplary
embodiment of FIG. 2. The hot power line 221 and the neutral power
line are connected to the line voltage dimming card 130 at
connectors CON1 and CON2 respectively. The output power lines 280,
285, and 290 are connected to connector CON3 to receive power for a
light source.
[0053] The surge protection circuit 225 includes a capacitor C9 and
a varistor V1. The varistor V1 acts to divert any voltage surges
present along the hot line 221 in order to protect the circuitry in
the line voltage dimming card 130.
The relay drive circuit 245 includes a field effect transistor
(FET) Q2 for controlling the relay 247. The relay drive circuit 245
receives a control signal PROC_RLDR from the microprocessor 205 and
opens or closes the relay 247 based on this control signal
PROC_RLDR. The control signal PROC_RLDR is applied to the base 1 of
the FET Q2 which allows current flow through a channel between
points 2 and 3 of the FET Q2 when the PROC_RLDR signal is above a
threshold voltage. This flow of current drives a coil in relay 247
to close. In one exemplary embodiment, without this flow of
current, the relay 247 remains open.
[0054] The dimmer drive circuit 255 includes an optoisolator triac
driver IC8, two resistors R5, R7, and a capacitor C2. The triac
driver IC8 receives a dimmer controller signal OPTO_TRIAC from the
microprocessor 205. Based on the dimmer control signal OPTO_TRIAC,
the triac driver IC8 energizes the dimmer 257 to allow current to
flow from the switched output power line 285 through the dimmer
257, through an inductor 265, and to the dimmed output power line
290 at CON3. As the triac dimmer 257 and the inductor 265 can be
large devices, in a panel embodiment, these devices 257, 265 can be
mounted external from the line dimming voltage card 130. Exemplary
values for the components of the surge protection circuit 225, the
relay drive circuit 245, and the dimmer drive circuit 255 are
listed below in Table 8.
TABLE-US-00008 TABLE 8 Exemplary Component Values for the Surge
Protection Circuit 225, the Relay Drive Circuit 255, and the Dimmer
Drive Circuit 255 Circuit Component Value R1 1 M.OMEGA. R2
(thermistor) Variable proportional to temperature R3 1 M.OMEGA. R4
1 M.OMEGA. R5 (thermistor) Variable proportional to temperature R6
(thermistor) Variable proportional to temperature R7 (thermistor)
Variable proportional to temperature C1 1 .mu.F C2 100 nF
[0055] FIG. 8 is an electrical circuit diagram depicting exemplary
serial communication circuits 212-1, 212-2 and exemplary optical
isolation circuits 210-1, 210-2 of a line voltage dimming card 130
in accordance with the exemplary embodiment of FIG. 2. The
exemplary serial communication circuits 212-1 and 212-2 provide
serial communications between the microprocessor 205 and the panel
controller 105.
[0056] The serial communication circuit 212-1 receives a serial
communication signal TX_OC at connector CON1 and transfers the
signal TX_OC to the optical isolation circuit 210-1, which in turn
transfers a representative signal PROC_RX to the microprocessor
205. The optical isolation circuit 210-1 includes an optocoupler
IC6 which provides electrical isolation between the panel
controller 105 and the microprocessor 205 for the serial
communication signals PROC_RX and TX_OC. The serial communications
circuit 212-1 and the optical isolation circuit 210-1 includes two
capacitors C20, C40 and three resistors R52, R54, R63.
[0057] The serial communication circuit 212-2 receives a serial
communication signal PROC_TX from the microprocessor 205 and
transfers the signal PROC_TX to the optical isolation circuit 210-2
which in turn transfers a representative signal TX_OC to the panel
controller 105. The optical isolation circuit 210-2 includes an
optocoupler IC7 which provides electrical isolation between the
panel controller 105 and the microprocessor 205 for the serial
communication signals PROC_TX and TX_OC. The serial communications
circuit 212-2 and optical isolation circuit includes a capacitor
C21 and three resistors R55, R61, R62. Exemplary values for the
components of the serial communication circuits 212-1, 212-1 and
the optical isolation circuits 210-1, 210-2 are listed below in
Table 9.
TABLE-US-00009 TABLE 9 Exemplary Component Values for the Serial
Communication Circuits 212-1, 212-2, and the Optical Isolation
Circuits 210-1 and 210-2 Circuit Component Value R1 (thermistor)
Variable proportional to temperature R2 (thermistor) Variable
proportional to temperature R3 3.3 k.OMEGA. R4 (thermistor)
Variable proportional to temperature R5 (thermistor) Variable
proportional to temperature R6 (thermistor) Variable proportional
to temperature C1 100 nF C2 100 nF C3 47 .mu.F
[0058] FIG. 9 is an electrical circuit diagram depicting examples
of a transformer 215 and a power supply circuit 217 of a line
voltage dimming card 130 in accordance with the exemplary
embodiment of FIG. 2. In this exemplary embodiment, the transformer
215 receives AC power from the panel controller 105 (See FIG. 1)
and steps the input voltage down to an appropriate voltage level
for the power supply circuit 217. The power supply circuit 217
receives the stepped down voltage from the transformer 215 and
employs a voltage regulator IC5 to provide a steady DC voltage to
the microprocessor 205. This exemplary power supply circuit 217
includes a rectifier circuit having four diodes D9, D10, D11, D12
connected across the secondary winding of the transformer 215. This
rectifier circuit converts the AC voltage received on the secondary
windings of the transformer 215 into a DC voltage. The power supply
circuit 217 also includes associated inductors, resistors,
capacitors, and a diode D8. Exemplary values for the components of
the power supply circuit 217 are listed below in Table 10.
TABLE-US-00010 TABLE 10 Exemplary Component Values for the Power
Supply Circuit 217 Circuit Component Value C1 100 nF C2 47 .mu.F C3
100 nF C4 47 .mu.F C5 100 nF L1 22 .mu.H L2 22 .mu.H
[0059] Although specific embodiments of the invention have been
described above in detail, the description is merely for purposes
of illustration. It should be appreciated, therefore, that many
aspects of the invention were described above by way of example
only and are not intended as required or essential elements of the
invention unless explicitly stated otherwise. Various modifications
of, and equivalent steps corresponding to, the disclosed aspects of
the exemplary embodiments, in addition to those described above,
can be made by a person of ordinary skill in the art, having the
benefit of this disclosure, without departing from the spirit and
scope of the invention defined in the following claims, the scope
of which is to be accorded the broadest interpretation so as to
encompass such modifications and equivalent structures.
* * * * *