U.S. patent application number 10/124077 was filed with the patent office on 2002-11-21 for networkable power controller.
This patent application is currently assigned to Power Circuit Innovations, Inc.. Invention is credited to Adamson, Hugh Patrick.
Application Number | 20020171379 10/124077 |
Document ID | / |
Family ID | 22411567 |
Filed Date | 2002-11-21 |
United States Patent
Application |
20020171379 |
Kind Code |
A1 |
Adamson, Hugh Patrick |
November 21, 2002 |
Networkable power controller
Abstract
A networkable power controller includes a mode selector for
selectively conducting one of a plurality of input signals to an
output of the networkable power controller, where the input signals
and the output signals satisfy the same signaling protocol. The
networkable power controller may be networked with other
networkable power controllers, lighting ballasts and other building
automation control devices, and user-controlled voltage selectors
to provide a lighting control network. A power controller may
include a mode selector that may be used in combination with other
control devices or components, including a rotary dimmer control, a
digital slide dimmer control, a demand load shedder component, a
photometer component, and a communications interface. The
communications interface allows digital control of the networkable
power controller.
Inventors: |
Adamson, Hugh Patrick;
(Boulder, CO) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
Power Circuit Innovations,
Inc.
Boulder
CO
|
Family ID: |
22411567 |
Appl. No.: |
10/124077 |
Filed: |
April 16, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10124077 |
Apr 16, 2002 |
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09522390 |
Mar 10, 2000 |
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6400103 |
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60123899 |
Mar 11, 1999 |
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Current U.S.
Class: |
315/312 |
Current CPC
Class: |
H05B 47/175 20200101;
H05B 47/165 20200101; H04L 2012/285 20130101; H04L 12/282 20130101;
H04L 2012/2843 20130101; H05B 41/3921 20130101; H04L 12/2803
20130101; H05B 47/17 20200101; H05B 47/18 20200101 |
Class at
Publication: |
315/312 |
International
Class: |
H05B 037/00 |
Claims
We claim:
1. A lighting controller for controlling at least one ballast
driving a lighting device, the lighting controller comprising: an
output signal line adapted to output an output signal satisfying a
signaling protocol, the signaling protocol defining a control
signal for controlling an amount of power provided to the lighting
device by the ballast; a first input signal line adapted to receive
a first input signal satisfying the signaling protocol; a second
input signal line adapted to receive a second input signal
satisfying the signaling protocol; and a mode selector selecting
among a plurality of modes, each mode determining which of the
first input signal and the second input signal are conducted to the
output signal line to control the ballast.
2. The lighting controller of claim 1 wherein the mode selector
selects a mode in which the first input signal is conducted to the
output signal line, independent of a signal level of the second
input signal.
3. The lighting controller of claim 1 wherein the mode selector
selects a mode in which the one of the first input signal and
second input signal having a higher signal level is conducted to
the output signal line.
4. The lighting controller of claim 1 wherein the mode selector
selects a mode in which the one of the first input signal and
second input signal having a lower signal level is conducted to the
output signal line.
5. The lighting controller of claim 1 wherein the signaling
protocol defines a direct current control signal ranging from a low
voltage level to a high voltage level and indicating an
illumination level to be generated by the lighting device.
6. The lighting controller of claim 1 further comprising: an output
port for the output signal line; an input port for each input
signal line; a power bus for transferring power between each of the
ports in the lighting controller; the output port including a first
pair of power bus leads coupled to the power bus and the output
signal line, the first pair of power bus leads including a power
lead and a ground lead; and the input port including a second pair
of power bus leads coupled to the power bus and one of the first
input signal line and the second input signal line, the second pair
of power bus leads including a power lead and a ground lead.
7. The lighting controller of claim 6 wherein the power bus leads
of the output port are coupled to an auxiliary power output from
the ballast.
8. The lighting controller of claim 7 wherein the auxiliary power
output from the ballast is coupled to a winding in a power factor
circuit of the ballast.
9. The lighting controller of claim 7 as a first lighting
controller wherein power is transferred from the first lighting
controller to another lighting controller having any port coupled
to a port of the first lighting controller.
10. The lighting controller of claim 6 as a first lighting
controller, wherein first input signal includes a control signal
and the first input port is adapted to couple to the output port of
another lighting controller and to transfer the control signal from
the additional lighting controller to the first lighting
controller.
11. The lighting controller of claim 10 wherein the power provided
from the lighting controller is derived from current generated by a
power factor circuit of the ballast and is cascaded to the first
additional lighting controller via the power bus and the first
input port.
12. The lighting controller of claim 6 wherein a first current
generated by a power factor circuit of the ballast and a second
current generated by a power factor circuit of another ballast are
applied in parallel to power the lighting controller.
13. The lighting controller of claim 1 wherein the second input
signal includes a control signal and the second input port is
coupled to the output of a controllable voltage selector that
generates the second input signal satisfying the signaling
protocol.
14. The lighting controller of claim 13 wherein the signaling
protocol defines a direct current control signal ranging from a low
voltage level to a high voltage level and indicates an illumination
level to be generated by the lighting device.
15. The lighting controller of claim 13 wherein the controllable
voltage selector comprises: a photometer component that generates
the second input signal based on detection of manually applied
light from a non-ambient light source.
16. The lighting controller of claim 15 wherein the photometer
component comprises: a non-ambient light detector and an ambient
light detector to determine a signal level of the second input
signal based on a relationship between a duration of non-ambient
light detected by the non-ambient light detector and an
illumination level of ambient light detected by the ambient light
detector.
17. The lighting controller of claim 13 wherein the controllable
voltage selector comprises: a demand load shedder including at
least two selectable load selectors and outputting a load shedder
control signal level as the second input signal; and each
selectable load selector providing a different load shedder control
signal level, wherein selection of a load selector alters the
second input signal to a load shedder control signal level
associated with a selected load selector.
18. The lighting controller of claim 17 wherein the selection of a
load selector causes the signal level of the second input signal to
change gradually over a predetermined time period.
19. The lighting controller of claim 13 wherein the controllable
voltage selector comprises: a potentiometer generating the second
input signal.
20. The lighting controller of claim 13 wherein the controllable
voltage selector comprises: a digital counter and a
digital-to-analog converter generating the second input signal.
21. The-lighting controller of claim 13 wherein the controllable
voltage selector comprises: a communications interface receiving a
digital command signal and converting the digital command signal to
the second input control signal.
22. The lighting controller of claim 21 wherein the digital command
signal controls the mode selector in selecting the given mode.
23. The lighting controller of claim 21 wherein the communications
interface comprises: an addressable component associated with one
or more predetermined addresses, the addressable component allowing
the lighting controller to respond only to a digital command signal
associated with at least one of the predetermined addresses.
24. A method for networking a lighting controller that controls at
least one ballast driving a lighting device, the lighting
controller including an output signal line adapted to output an
output signal, a first input signal line adapted to receive a first
input signal, a second input signal line adapted to receive a
second input signal, wherein the output signal, the first input
signal, and the second input signal satisfy the same signaling
protocol that defines a control signal for controlling an amount of
power provided to the lighting device by the ballast, the method
comprising: coupling an output of an additional lighting controller
to the first input signal line of the lighting controller; coupling
a user controllable voltage selector to the second input signal
line of the lighting controller; and selecting a given mode among a
plurality of modes, each mode determining which of the first input
signal and the second input signal are conducted to the output
signal line.
25. The method of claim 24 further comprising: controlling the at
least ballast with the output signal in accordance with the given
mode.
26. The method of claim 24 further comprising: powering the
lighting controller using current derived from the ballast.
27. The method of claim 24 wherein the operation of selecting a
given mode comprises: selecting the given mode to cause the first
input signal to be conducted to the output signal line, independent
of a signal level of the second input signal.
28. The method of claim 24 wherein the operation of selecting a
given mode comprises: selecting the given mode to cause the one of
the first input signal and the second input signal having a higher
signal level to be conducted to the output signal line.
29. The method of claim 24 wherein the operation of selecting a
given mode comprises: selecting the given mode to cause the one of
the first input signal and the second input signal having a lower
signal level to be conducted to the output signal line.
30. A power controller for controlling a driver circuit for driving
a electrical device in a building control system, the power
controller comprising: an output signal line adapted to output an
output signal satisfying a signaling protocol, the signaling
protocol defining a control signal for controlling an amount of
power provided to the electrical building device by the driver
circuit; an input signal line adapted to receive an input signal
satisfying the signaling protocol; a communications interface
receiving a digital command signal and converting the digital
command signal to the input signal on the input signal line; and a
selecting circuit conducting the input signal to the output signal
line to control the driver circuit.
31. The power controller of claim 31 wherein the communications
interface includes an addressable component associated with one or
more predetermined addresses, the addressable component allowing
the power controller to respond only to a digital command signal
associated with at least one of the predetermined addresses.
32. The power controller of claim 31 wherein the driver circuit is
a ballast and the electrical device is a lighting device.
33. The power controller of claim 31 wherein the electrical device
is a building automation control device and the driver circuit is a
power supply control circuit to the building automation control
device.
34. A method for networking a power controller that controls at
least one driver circuit that drives an electrical device in a
building control system, the power controller including an output
signal line adapted to output an output signal, an input signal
line adapted to receive an input signal, wherein the output signal
and the input signal satisfy the same signaling protocol that
defines a control signal for controlling an amount of power
provided to the electrical building device by the driver circuit,
the method comprising: receiving a digital command signal via a
communications interface; converting the digital command signal to
the input signal; and conducting the input signal to the input
signal line of the power controller; and coupling the input signal
line to the output signal line to output the input signal as the
output signal to control the driver circuit.
35. The method of claim 34 further comprising: selecting a given
mode from a plurality of selection modes, each mode setting a
criterion for coupling the input signal line to the output signal
line; wherein the coupling operation is dependent upon the
criterion being satisfied by the input signal line.
36. The method of claim 34 wherein the digital command signal is
associated with a unique identifier, and further comprising:
determining whether the digital command signal is directed to the
power controller based on the unique identifier.
37. The method of claim 34 wherein the operation of converting the
digital command signal is conditional upon the determining
operation determining that the digital command signal is directed
to the power controller based on the unique identifier.
38. The method of claim 37 further comprising: outputting a
controlled amount of power from the driver circuit to the
electrical device in the building control system, based on the
output signal.
39. A power controller for controlling at least one driver circuit
driving a building automation device, the power controller
comprising: an output signal line adapted to output an output
signal satisfying a signaling protocol, the signaling protocol
defining a control signal for controlling an amount of power
provided to the building control device by the driver circuit; a
first input signal line adapted to receive a first input signal
satisfying the signaling protocol; a second input signal line
adapted to receive a second input signal satisfying the signaling
protocol; and a mode selector selecting among a plurality of modes,
each mode determining which of the first input signal and the
second input signal are conducted to the output signal line to
control the driver circuit.
40. The power controller of claim 39 further comprising: an output
port for the output signal line; an input port for each input
signal line; a power bus for transferring power between each of the
ports in the power controller; the output port including a first
pair of power bus leads coupled to the power bus and the output
signal line, the first pair of power bus leads including a power
lead and a ground lead; and the input port including a second pair
of power bus leads coupled to the power bus and one of the first
input signal line and the second input signal line, the second pair
of power bus leads including a power lead and a ground lead.
41. The power controller of claim 40 wherein the power bus leads of
the output port are coupled to an auxiliary power output from the
circuit.
42. The power controller of claim 41 as a first power controller
wherein power is transferred from the first power controller to
another power controller having any port coupled to a port of the
first power controller.
43. The power controller of claim 40 as a first power controller,
wherein first input signal includes a control signal and the first
input port is adapted to couple to the output port of another power
controller and to transfer the control signal from the additional
power controller to the first power controller.
44. The power controller of claim 43 wherein the power provided
from the power controller is derived from current generated by a
power factor circuit of the driver circuit and is cascaded to the
first additional power controller via the power bus and the first
input port.
45. A method for networking a power controller that controls at
least one driver circuit driving a building automation control
device, the power controller including an output signal line
adapted to output an output signal, a first input signal line
adapted to receive a first input signal, a second input signal line
adapted to receive a second input signal, wherein the output
signal, the first input signal, and the second input signal satisfy
the same signaling protocol that defines a control signal for
controlling an amount of power provided to the building automation
control device by the driver circuit, the method comprising:
coupling an output of an additional power controller to the first
input signal line of the power controller; coupling a user
controllable voltage selector to the second input signal line of
the power controller; and selecting a given mode among a plurality
of modes, each mode determining which of the first input signal and
the second input signal are conducted to the output signal
line.
46. The method of claim 45 further comprising: powering the
lighting controller using current derived from the ballast.
47. The method of claim 45 wherein the operation of selecting a
given mode comprises: selecting the given mode to cause the one of
the first input signal and the second input signal having a higher
signal level to be conducted to the output signal line.
48. The method of claim 45 wherein the operation of selecting a
given mode comprises: selecting the given mode to cause the one of
the first input signal and the second input signal having a lower
signal level to be conducted to the output signal line.
49. A power controller for a power network having a plurality of
the power controllers for controlling the passage of control
signals through the power network, each of the power controllers
having a local control device generating a local control signal at
the power controller, the power controller comprising: a first
input port receiving the local control signal; a second input port
receiving a remote control signal, the second control signal being
passed from another power controller in the network; a mode
selector logically gating the local control signal or the remote
control signal to under predetermined conditions to an output port
for passage as a gated control signal to another power controller
in the network or out of the network of power controllers to
control a power device.
50. The power controller of claim 49 and in addition: a buffer
amplifier isolating the gated control signal passed to the output
port from the control signal at an input port.
51. The power controller of claim 49 wherein the mode selector
comprises: a switch positioned to pass one or the other of the
local control signal and the remote control signal.
52. The power controller of claim 49 wherein the mode selector
comprises a logic circuit to pass the greater of the local control
signal and the remote control signal.
53. The power controller of claim 49 wherein the mode selector
comprises a logic circuit to combine the local control signal with
the remote control signal to generate the gated control signal.
54. A power network configured from a plurality of the power
controllers with each power controller defined as in claim 49.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/123,899, filed Mar. 11, 1999, entitled
"Networking Controls For Power Controlling Ballast".
[0002] The present application is also related to U.S. patent
application Ser. No. 08/982,975, filed Dec. 2, 1997, entitled
"Frequency Controlled, Quick and Soft Start Gas Discharge Lamp
Ballast and Method Therefor" U.S. patent application Ser. No.
08/982,974, filed Dec. 2, 1997, entitled "Frequency Controller with
Loosely Coupled Transformer Having A Shunt With A Gap And Method
Therefor", and U.S. patent application Ser. No. 09/315,395, filed
May 20, 1999, entitled "Light Sensing Dimming Control System for
Gas Discharge Lamps".
TECHNICAL FIELD
[0003] The invention relates generally to building control systems,
and more particularly to networkable power controllers used to
control electrical or electro-mechanical systems in buildings.
BACKGROUND OF THE RELATED ART
[0004] A building control system generally allows a building
operator to control a building system within one or more buildings,
such as an HVAC system (heating, ventilation, and air conditioning
system), a lighting system, a water and waste system, or a security
system. For example, a building control system may include a
centralized or remote building control station from which a
building operator may configure thermostat setting schedules and
monitor temperatures in various building zones. In this manner, a
building operator can manage energy use and tenant comfort in
accordance with the anticipated building usage during various hours
of the day.
[0005] In addition, an open systems standard for building control
system networks, called BACnet, has become an important standard in
the building control industry. BACnet is a data communication
protocol for building automation and control networks. Using
BACnet, a building operator can control and monitor
building-related devices distributed throughout a network in a
building. Such BACnet-compliant device may include without
limitation furnaces, air conditioning systems, cooling towers, heat
exchangers, lighting systems, dampers, actuators, sensors, security
cameras, and other building-related devices.
[0006] Modern building control systems, however, do not commonly
accommodate personal overrides of the centrally controlled
settings. As such, an employee working on a weekend may be left
without adequate air conditioning on a hot summer day. Typically,
the employee must contact a building operator at the central
control station to change the temperature setting for his or her
office. In addition, even with the cooperation of the central
control station, many building control systems lack the precision
to override the scheduled temperature settings on merely an
individual office basis. Instead, the temperature setting of an
entire zone or floor of the building is temporarily modified to
accommodate the single employee's needs. Such imprecision
diminishes the energy saving effect of the scheduled thermostat
settings.
[0007] Individualized control of lighting systems and other
building systems is also desirable, although not adequately
addressed by existing solutions. For example, a building operator
may schedule lighting on a floor in a building to be turned off (or
turned down in intensity) after normal office hours to save energy.
Without individual override control, an employee working late may
be left in the dark and be unable to continue working without
contacting the building operator to turn the lights back on.
[0008] Furthermore, it is not uncommon for large energy consumers,
such as a grocery store operator, to negotiate for lower rates from
a utility company in exchange for shedding its energy at the
utility's request. That is, if the building operator is willing to
reduce its energy consumption at the request of the utility during
peak demand periods (e.g., a hot summer day), the utility will
charge the building operator lower overall rates for its energy
consumption. For example, at a utility's request, a grocery store
may reduce the light intensity in the store gradually over a period
of time. Patrons and employees tend to automatically acclimate to
the slowly decreasing light intensity, without being aware of the
change.
[0009] However, a conventional method for achieving such a demand
reduction involves a store manager going from light switch to light
switch, incrementally reducing the light intensity of various
lights and/or lighting zones until the lighting throughout the
store has been reduced to the appropriate level. After the demand
shedding period is over, the store manager typically repeats this
time-consuming process in reverse, gradually increasing the light
intensity to its normal level.
[0010] In addition, existing lighting control systems typically
entail considerable costs and provide limited flexibility in
configuring and powering a control network. A problem exists in
providing an inexpensive network of lighting subsystems that can be
installed easily throughout a building and powered conveniently by
an available energy source, while providing flexible control from a
central or remote control station with the convenience of
individual overrides.
SUMMARY OF THE INVENTION
[0011] The above and other problems are solved by a networkable
power controller that can conduct control signals for controlling
an electrical device, such as a ballast of a lighting device, a
BACnet device, etc. The networkable power controller can include
multiple inputs, an output, and a mode selector that selects a
control signal received at one of the inputs to be conducted to the
output. The inputs and the output support the same signaling
protocols so that multiple power controllers may be coupled
together to form a network. That is, the output signal of one power
controller, which is configured in accordance with the input
signals and the mode selector, may be used as an input signal of a
subsequent power controller. The output control signal can be used
to control the power provided to or by a building automation
control device in a building, including a lighting ballast or a
BACnet device. Alternatively, the output control signal may control
the operation of the building automation control device without
directly controlling the power provided to or by the device, such
as by including an analog or digital signal that causes the device
to internally alter building automation control device's
consumption or generation of power.
[0012] In addition, a power controller may be powered by power
received from one or more ballasts coupled to its output. In one
embodiment, the power is derived from a winding in the power factor
circuit of the ballast and passed into the lighting controller
through its output port. A power bus in the power controller
transfers the power, received at the controller's output port, to a
preceding device, such as a rotary light dimmer control, a demand
load shedder, or another lighting controller.
[0013] In one aspect of the present invention, a lighting
controller, which is an example of a power controller, that
controls at least one ballast driving a lighting device is
provided. An output signal line of the lighting controller is
adapted to output an output signal satisfying a signaling protocol.
The signaling protocol defining a signal format for driving the
ballast. A first input signal line is adapted to receive a first
input signal satisfying the signaling protocol. A second input
signal line is adapted to receive a second input signal satisfying
the signaling protocol. A mode selector selects among a plurality
of modes, each mode determining which of the first input signal and
the second input signal are conducted to the output signal
line.
[0014] In another aspect of the present invention, a method for
networking a power controller that controls at least one ballast
driving a lighting device is provided, The power controller
includes an output signal line adapted to output an output signal,
a first input signal line adapted to receive a first input signal,
and a second input signal line adapted to receive a second input
signal. The output signal, the first input signal, and the second
input signal satisfy the same signaling protocol. An output of an
additional power controller is coupled to the first input signal
line of the power controller. A user controllable voltage selector
is coupled to the second input signal line of the power controller.
A given mode is selected from among a plurality of modes. Each mode
determines which of the first input signal and the second input
signal are conducted to the output signal line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates inputs and output of a power
controller.
[0016] FIG. 2 illustrates an exemplary network of lighting
controllers in an embodiment of the present invention.
[0017] FIG. 3 depicts a logical representation for an embodiment of
the power controller.
[0018] FIG. 4 depicts an exemplary logical representation for an
embodiment of the present invention that includes a rotary
potentiometer.
[0019] FIG. 5 depicts an exemplary logical representation for an
embodiment of the present invention that includes a digital slide
dimmer.
[0020] FIG. 6 depicts an exemplary logical representation for an
embodiment of the present invention that includes a demand load
shedder.
[0021] FIG. 7 depicts an exemplary logical representation for an
embodiment of the present invention that includes a photometer
component.
[0022] FIG. 8 depicts an exemplary logical representation for an
embodiment of the present invention that includes a communications
interface.
[0023] FIG. 9 illustrates a flow diagram for networking a power
controller that controls at least one ballast driving a lighting
device.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0024] A networkable power controller includes a mode selector for
selectively conducting one of a plurality of input signals to an
output of the networkable power controller, where the input signals
and the output signals satisfy the same signaling protocol. The
networkable power controller may be networked with other
networkable power controllers, lighting ballasts, and
user-controlled voltage selectors to provide a lighting control
network. A power controller can include a mode selector that may be
used in combination with other control devices or components,
including a rotary dimmer control, a digital slide dimmer control,
a demand load shedder component, a photometer component, and a
communications interface, to provide a number of flexible
embodiments of the present invention.
[0025] FIG. 1 illustrates an embodiment of a power controller. A
power controller 100 includes two analog inputs 102 and 104 and an
analog output 106. The output 106 is adapted to control a driver
device designed to drive or provide power to an electrical device
or an electromechanical device, such as a lighting device or
another building automation control device. One example of a driver
device is a ballast of a lighting device, such as a fluorescent
light or other gas discharge light. An alternative example of a
driver device is a power supply control circuit for driving a
building automation control device, such as a BACnet-compatible
device.
[0026] The two inputs and the output support the same signaling
protocol, namely a 0.8 volt DC to 8 volt DC voltage control signal,
for controlling a ballast that drives a lighting device. In
alternative embodiments, other signaling protocols, including
without limitation a 2 volt to 8 volt signal, a 0 volt to 12 volt
signal, and a 0 volt to 10 volt signal, are contemplated within the
scope of the present invention. Alternative signal protocols, such
as signaling protocols for a BACnet interface, may also be employed
to define control signals to control a lighting ballast, HVAC
equipment, security systems, etc., depending on the input
requirements of the component devices.
[0027] The common signaling format between inputs and outputs of
the multiple power controllers 100 allows each controller to be
networked with other controllers. For example, the output 106 can
be coupled to the input of a subsequent power controller (not
shown) to extend the functionality of a single power controller
into a network of controllers. As such, multiple controllers may be
combined in a network to control many lighting devices throughout a
building.
[0028] The mode selector 108 allows a user, a building operator or
a building control system to configure the operation of the power
controller and, therefore, configure the operation of a given node
in a network. In the illustrated embodiment, a rotary switch allows
a user to select from among four configuration options or selection
modes, as shown in Table 1 with the criterion for each mode.
1TABLE 1 Mode Description of Criteria A The signal at input A is
conducted to the output 106 B The signal at input B is conducted to
the output 106 HI The signal of either input A or input B having
the highest signal level (e.g., voltage level) is conducted to the
output 106 LO The signal of either input A or input B having the
lowest signal level (e.g. voltage level) is conducted to the output
106
[0029] In alternative embodiments of the present invention, other
user or system switchable devices may be employed as a mode
selector, including buttons, sliders, keypads, programmed computers
and other input devices. Furthermore, alternative embodiments of
the present invention may have more or less than four modes from
which a user may select a desired mode. For example, an embodiment
of the present invention may provide more than two inputs similar
to inputs A and B, and therefore a mode selector may include mode
selections for each of the additional inputs as well as selections
for other criterion-related modes (e.g., the HI and LO selections).
Additional examples of alternative criterion-related modes include
a mode that combines the two input signals in some way. For
example, modes might include a mode that splits the difference
between two input signal levels, a mode that averages multiple
signal levels, a timed mode that conducts the input signal of one
input to the output 106 for a period of time and then switches to
conduct the signal of an alternate input to the output 106 for
another period of time.
[0030] The signaling protocol in one embodiment of the present
invention as a power controller provides a control signal to a
frequency controlled dimming ballast which controls the power
consumption of a gas discharge lamp by adjusting the electrical
power applied to the gas discharge lamp in response to the control
signal. The frequency controlled dimming ballast uses a
loosely-coupled transformer that controls the conduction of current
to the gas discharge lamp in response to an oscillating driving
signal. A more detailed discussion of a frequency controlled
dimming ballast may be found in U.S. patent application Ser. Nos.
08/982,975, filed Dec. 2, 1997, entitled "Frequency Controlled,
Quick and Soft Start Gas Discharge Lamp Ballast and Method
Therefor" and U.S. patent application Ser. No. 08/982,974, filed
Dec. 2, 1997, entitled "Frequency Controller with Loosely Coupled
Transformer Having A Shunt With A Gap And Method Therefor",
incorporated herein by reference for all that they disclose and
teach. Ballasts other than those described in the related patents
may be used with the controllers in the present invention.
[0031] FIG. 2 illustrates a network of lighting controllers, which
are exemplary power controllers, in one embodiment of the present
invention. It should be understood that alternative network
topologies may be configured without departing from the present
invention. A central control station 200 communicates a digital
signal to and from a communications interface 202. The central
control station 200 can generate commands to control a lighting
device, such as lighting devices 226, 228 and 230. The illustrated
embodiment shows a typical fluorescent lamp 226 including two gas
discharge bulbs coupled in series to a ballast 224 (BST). It should
be understood that the fluorescent lamp 226 is illustrated as a
lighting device in an exemplary embodiment of the present invention
and that alternative lighting devices, including other gas
discharge lamps, may be employed within the scope of the present
invention. Examples of alternative lighting devices include high
intensity discharge (HID) lamps, sodium lamps, and neon lamps.
[0032] The communications interface 202 (COMM INTRF) converts the
digital signal from the central control station 200 into an analog
control signal that satisfies the signaling protocol of the
lighting controller 206. A rotary dimmer control 204 is coupled to
a second input of the lighting controller 206 (CNTLR). The lighting
controller 206 is coupled to an input of another lighting
controller 210. Another rotary potentiometer control 208 is also
coupled to the lighting controller 210. The lighting controllers
may be cascaded together in a network to extend selectability and
control of lighting devices distributed throughout a building.
[0033] The lighting controllers in a network may be viewed as
controllable nodes in the network. Each controller according to its
mode selection passes or gates a local or remote control signal to
the next controller or output power device downstream from the
controller. For example, if lighting controller 210 is mode
selected to receive a local control signal from dimmer 208, than
that local control signal will be passed as the remote control
signal input to controllers 214 and 218. In this way, the effect of
a local control signal at a controller becomes the remote control
signal to controllers connected downstream from that controller. Of
course the downstream controllers may be mode selected to use their
own local control signal, the remote control signal or a logical
choice of either depending upon the mode selector.
[0034] In FIG. 2, the output port of controller 206 is connected to
an input port of controllers 210 and 238. Lighting controller 210
in the network is a node at the entry to a sub-network or zone 234
of the network. This sub-network includes controllers 218 and 214,
ballasts 220, 222 and 224, and lamps 226, 228 and 230. Lighting
controller 218 controls two ballasts 222 and 224, where each
ballast drives lamps 228 and 226 respectively. Lighting controller
214 controls ballast 220 which drives lamp 230. The remote control
signal for this sub-network 234 would come from controller 210,
controller 206 or central control station 200 (converted via
interface 202) depending upon the mode settings in controllers 206
and 210. Outside zone 234, lighting controller 238 controls ballast
240 which drives lamp 242. Controller 238 may receive a local
control signal from dimmer 244 or a remote control signal from
controller 206 or central control station 200.
[0035] When the network is viewed at a building or site level, the
illustrated embodiment of FIG. 2 represents an exemplary
configuration of a building's lighting controller network. The
central control station 200, through the communications interface
202, provides an input control signal to the lighting controller
206. Likewise, the rotary control 204 also provides an input
control signal to the lighting controller 206. Depending on the
setting of the mode selector 232, one or the other of the input
signals is conducted to one of the inputs of the lighting
controller 210. For example, the rotary control 204 may represent
an emergency lighting switch, which is intended to turn all the
lights in a building or zone up (i.e., to a higher illumination
level) in an emergency. In contrast, the central control station
200 may provide scheduled illumination changes throughout the day
or week (e.g., after midnight, the lights in the building are
dimmed to a minimal level). Accordingly, in an emergency, the
rotary control 204 may be turned up to full intensity in order to
turn up all the lights in the building. As such, the mode selector
232 in the lighting controllers 206, 210, 238, 214 and 218 are set
to conduct the control signal having the highest signal level to
the output of the lighting controller 206. In this fashion, the
rotary control 204 overrides the scheduled setting of the central
control station 200 and brings up the lights in the building.
[0036] In an alternative embodiment, an inverse polarity
relationship exists between the control signal and the light
intensity of a lighting device. Therefore, the rotary control 204
would input a low signal level and the mode selector 232 would be
set to conduct the lowest signal to its output in order to increase
the light intensity in a building. The rotary control 208 is an
override control coupled to the lighting controller 210. Other
modes may include timed modes, which switch to other modes after a
predetermined period of time, and averaging modes, which output the
average or one or more input signal levels.
[0037] With the mode selector in controllers 210, 214 and 218 set
to pass the highest signal level (i.e., corresponding to the
highest light intensity level) the rotary control 208 may be used
to increase the illumination in a given zone 234, overriding the
remote control signal output from the lighting controller 206.
Alternatively, the lighting controller 210 may be set to pass
strictly one or the other of the input signals or the input signal
having the lowest level.
[0038] In a similar fashion, the rotary control 244 may be used,
depending on the mode selector setting, to override the input
signal from the lighting controller 206 to the lighting controller
238. For example, the lamp 242 may represent a lamp over an
individual work area. The lamp 242 is powered and controlled by way
of the ballast 240. If the mode selector of the lighting controller
238 is set appropriately, the individual worker can override an
energy saving signal from the central control station 200 merely by
increasing the illumination at the rotary control 244. In this
manner, the worker can maintain a desired illumination level, while
the building operator maintains energy savings throughout the rest
of the building.
[0039] In an embodiment of the present invention, each ballast is
powered by conventional AC power source and has its own power
supply or power factor circuit to generate DC power. The power
factor circuit includes a winding and circuitry from which DC power
is derived to auxiliary DC power outside the ballast. An example of
a ballast providing auxiliary DC power outside the ballast may be
found U.S. Pat. No. 5,933,340, issued Aug. 3, 1999, entitled
"Frequency Controller with Loosely Coupled Transformer Having A
Shunt With A Gap And Method Therefor", As will be described in FIG.
3, the auxiliary power from the ballast may be passed back to and
through the cascading controllers preceding the ballast in the
network to power the controllers and devices connected to the
controllers.
[0040] FIG. 3 depicts a logical representation for a power
controller in one embodiment of the present invention. Power
controller 300 includes three ports: Input A port 302, Input B port
304, and Output port 306. In an alternative embodiment, additional
ports may be included in the power controller. Each port includes
three leads: a power lead, a ground lead, and a signal lead. An
input port is used to couple the controller 300 to a preceding
controller or another control device, such as user-controlled
voltage selector, providing a local control signal. In addition, an
output port may be coupled to a succeeding controller or a driving
device, such as a ballast.
[0041] A power bus in controller 300 consists of a power line 310
and a ground line 308. The power bus transfers power from the
output port 306 through the controller to the input ports 302 and
304. In this manner, power provided to the controller 300 (e.g., by
a ballast or by a ballast through a controller) is transferred to
power all other controllers or local devices (e.g., rotary
controls, communications interfaces, and other devices connected to
the controllers) in the network. For example, in FIG. 2 auxiliary
DC power from ballasts 220, 222, 224 and 240 is effectively
connected in parallel to and through controllers 206, 210, 214, 218
238, control devices 204, 208, 212, 216, and 244, and communication
interface 202. The combination of power lines, ground lines and
control lines are indicated in FIG. 2 as thick black lines.
[0042] The controller 300 includes a voltage regulator 312 coupled
to the power line 310 to provide a regulated DC voltage to power
the controller itself. In an embodiment of the present invention,
the internal power generated by the regulator 312 is a positive 12
volts DC; however, other internal power levels are contemplated
within the scope of the present invention.
[0043] Each of the ports has a signal line 314. The signal line is
designated to support a single signaling protocol for both inputs
and outputs. In one embodiment and present invention, the signaling
protocol defines an analog control signal from zero to 12 volts DC.
Note that only a signal range of 3 through 8 volts is needed to
control the illumination through a typical ballast; however, a
larger range is supported to allow customization of control signals
using other voltage levels, such as to support a BACnet-compliant
device. A buffer amplifier 330 amplifies and isolates the output
signal from the input and drives a control signal out to a
subsequent power controller or ballast.
[0044] A mode selector 316 allows the leading controller to be
configured for a given mode of operation. In an embodiment of
present invention, each mode of operation determines which input
signal is to be logically gated to the output port for passage as a
gated control signal to a next controller or power device. A mode
associated with selector lead 318 gates the signal from the Input A
to the output port 306. A mode associated with selector lead 324
gates the signal from the Input B to the output port 306.
[0045] The mode associated with selector lead 320 logically gates
the input signal having the lowest signal level to the output port
306. In this mode, if the Input A signal has the lowest signal
level, the diode 326 is forward-biased, pulling the voltage of lead
320 to the signal level of the Input A signal. However, if the
Input A signal has the highest signal level, the diode 326 is
reverse-biased, pulling the voltage of lead 320 to the signal level
of the Input B signal.
[0046] The mode associated with selector lead 322 propagates the
input signal having the lowest signal level to the output port 306.
In this mode, if the Input A signal has the highest signal level,
the diode 328 is forward-biased, pulling the voltage of lead 322 to
the signal level of the Input A signal. However, if the Input A
signal has the lowest signal level, the diode 328 is
reverse-biased, pulling the voltage of lead 322 to the signal level
of the Input B signal.
[0047] In the illustrated embodiment, the mode selector 316 is
shown as a rotary switch with logic circuit--diodes 326 and 328 and
associated resistors--coupling an output signal line to one of four
possible input signal lines. In alternative embodiments, however, a
different type of mode selector may be employed, such as a
multi-button selector (e.g., one button for each mode), a keypad, a
slider control or a micro-controller as described hereinafter in
FIG. 8. Furthermore, a mode selector capable of selecting between
more than two inputs is contemplated within the scope of the
present invention. In yet another alternative embodiment, the mode
selector may also couple an input signal line to one of a plurality
of output signal lines.
[0048] The power controller of FIG. 3 may be combined with other
devices, such as ports, a user-controlled voltage selectors, and
other analog and digital circuitry, to form a more complex device.
FIGS. 4 through 8 illustrate exemplary embodiments of such complex
devices in accordance with other embodiments of the present
invention.
[0049] FIG. 4 depicts an exemplary logical representation for an
embodiment of the present invention that includes a rotary
potentiometer as a user-controlled voltage selector. A rotary
dimmer device 400 includes a rotary potentiometer 410 and a mode
selector 402. A buffer 412 amplifies and isolates the output signal
to satisfy the signaling protocol and to drive a subsequent power
controller or ballast.
[0050] The rotary potentiometer 410 is powered by an internal
source voltage output from a regulator 404, which receives current
from a power bus 414. The output signal of the rotary potentiometer
410 is conducted to one of the inputs (e.g., Input A) of the mode
selector 402. As such, the rotary potentiometer 410 may be rotated
by user to alter the input voltage to the mode selector 402.
Although a rotary potentiometer is illustrated and described with
regard to FIG. 4, other types of potentiometers may be employed to
select an input voltage in accordance with the present invention,
including a sliding potentiometer.
[0051] An input port 408 is adapted to receive a second input
signal to the mode selector 402. Using the input port 408, a
preceding mode selector, user-controlled voltage selector, or other
control device may be coupled to the rotary dimmer device 400 to
configure a power controller network. Depending on the mode
selector setting in the mode selector 402, the input voltage of the
rotary potentiometer 410 may be conducted to the output port 406 of
the rotary dimmer device 400 to control a ballast or to provide an
input signal to a subsequent mode selector. In an alternate mode
setting, the control signal received via the input port 408 may be
conducted to the output port 406 of the rotary dimmer device
400.
[0052] FIG. 5 depicts an exemplary logical representation for an
embodiment of the present invention that includes a digital slide
dimmer as a controlled voltage selector. A digital slide dimmer
device 500 includes a digital counter 510, a digital-to-analog
converter 508, and a mode selector 502. A buffer 512 amplifies and
isolates the output signal of the mode selector 502 to satisfy the
signaling protocol and to drive a subsequent power controller or
ballast.
[0053] The logic within the digital slide dimmer device 500 is
powered by internal source voltage output from a regulator 504,
which receives current from a power bus 518. The counter 510
increments while a switch 516 is closed and decrements while a
switch 514 is closed. The switches 514 and 516 may be controlled,
for example, by a user-controlled slide control that closes the
switch 516 when it is moved in one direction and closes the switch
514 when it is move in the opposite direction. The output of the
counter 510 is a digital signal representing the current value of
the counter 510. This digital signal is received by the
digital-to-analog converter 508 and converted into an analog
voltage signal, which is conducted to one of the inputs (e.g.,
Input A) of the mode selector 502. A display 506 provides a
user-observable indication of the current value of the counter 510,
such as by way of a numeric LED (Light Emitting Diode) display or
LCD (Liquid Crystal Display). Although a digital slide dimmer is
illustrated and described with regard to FIG. 5, other types of the
digital controls and digital voltage selectors may be employed to
select an input voltage in accordance with the present invention,
such as a keypad or a rocker switch.
[0054] In an alternative embodiment, a time may also be included in
the logic of the digital slide dimmer 500 to gradually modify the
control signal over a predetermined period of time. For example,
when a building operator decreases the digital slide dimmer
setting, the illumination controlled by the digital slide dimmer
500 decreases to the newly set level over a period of 5 seconds,
based on the setting of the timer.
[0055] An input port 522 is adapted to receive a second input
signal to the mode selector 502. Using the input port 522, a
preceding mode selector, user-controlled voltage selector, or other
control device may be coupled to the digital slide dimmer device
500 to configure a power controller network. Depending on the mode
selector setting in the mode selector 502, the input voltage
generated by the digital-to-analog converter 508 may be conducted
to the output port 520 of the digital slide dimmer device 500 to
control a ballast or to provide an input signal to a subsequent
mode selector. In an alternate mode setting, the control signal
received via the input port 522 may be conducted to the output port
520 of the digital slide dimmer 500.
[0056] FIG. 6 depicts an exemplary logical representation for an
embodiment of the present invention that includes a demand load
shedder as a controlled voltage selector. A demand load shedder
device 600 includes a digital counter 610, a digital-to-analog
converter 608, and a mode selector 602. A buffer amplifier 612
amplifies and isolates the output signal of the mode selector 602
to satisfy the signaling protocol and to drive a subsequent power
controller or ballast.
[0057] Furthermore, in one embodiment of the present invention, an
external control module 616 may be connected to the demand load
shedder device 600 to provide external control means. For example,
the external control module 616 may be coupled to a TCP/IP client.
The client may receive a command (e.g., in the form of email from a
utility) to decrease energy consumption. The external control
module 616 can then trigger the demand load shedder device 600 to
decrease its output signal, thereby decreasing illumination and
energy consumption gradually to a predefined level (e.g., 70% of
normal illumination). In addition, in response to another command
signal indicating that the decrease in consumption is no longer
required, the external control module 616 can then trigger the
return to the normal illumination level. In an alternative
embodiment, the external control module 616 can monitor the voltage
and current entering a building. If the energy consumption reaches
a predetermined threshold, the external control module 616 triggers
the demand load shedder device to decrease the illumination
gradually to a predefined level, at least until the excessive
consumption is over.
[0058] The logic within the demand load shedder device 600 is
powered by internal source voltage output from a regulator 604,
which receives current from a power bus 618. Within the limits set
by the limits module 614, the counter 610 increments while a load
selector switch 626 is closed (or a transistor 624 is on) and
decrements while a load selector switch 20 628 is closed (or a
transistor 630 is on). In the illustrated embodiment, two buttons
(not shown) are used to control the load selector switches 626 and
628. The load selector switch 626 corresponds to a voltage which is
a load shedder control signal level indicating a normal
illumination level, as set in the limits module 614. The load
selector switch 628 corresponds to a voltage, which is a load
shedder control signal level indicating an illumination level at
70% of normal, as set in the limits module 614. When the switch 626
is closed, the voltage gradually decreases (e.g., over a period of
5 minutes) from its normal setting to a voltage setting that
indicates the decrease to 70% of normal illumination. The time
period of the gradual decrease may be controlled by a settable
timer or clock rate module in the counter 610. In an alternative
embodiment, the high and low limits may be set to alternative
values. For example, the high limit may be set to less than 100% of
normal illumination and the low limit may be set to provide more or
less than 70% of normal illumination. Alternative embodiments
providing more than two illumination settings are also contemplated
in accordance with the present invention.
[0059] The load selector switches 626 and 628 may each be
controlled, for example, by a controlled button that close one of
the corresponding load selector switches when depressed.
Alternatively, the counter 610 may be incremented or decremented by
the controls, such as a three-position rocker switch (increment,
decrement, neutral), a rotary control, or the external control
module 616, which is designed to increment the counter 610 by
turning on the transistor 624 (and turning off the transistor 630)
and to decrement the counter 610 by turning on the transistor 630
(and turning off the transistor 624). The output of the counter 610
is a digital signal representing the current value of the counter
610. This digital signal is received by the digital-to-analog
converter 508 and converted into an analog voltage signal, which is
conducted to one of the inputs (e.g., Input A) of the mode selector
602. A display 606 provides a user-observable indication of the
current value of the counter 610, such as by way of a numeric LED
display or LCD.
[0060] An input port 622 is adapted to receive a second input
signal to the mode selector 602. Using the input port 622, a
preceding mode selector, user-controlled voltage selector, or other
control device may be coupled to the demand load shedder device 600
to configure a power controller network. Depending on the mode
selector setting in the mode selector 602, the input voltage
generated by the digital-to-analog converter 608 may be conducted
to the output port 620 of the demand load shedder device 600 to
control a ballast or to provide an input signal to a subsequent
mode selector. In an alternate mode setting, the control signal
received via the input port 622 may be conducted to the output port
620 of the demand load shedder device 600.
[0061] FIG. 7 depicts an exemplary logical representation for an
embodiment of the present invention that includes a photometer
component as part of a controlled voltage selector. A laser
controlled dimmer device 700 includes a photometer component 714,
phototransistors 726 and 728, a digital counter 710, and a
digital-to-analog converter 708. A buffer 712 amplifies and
isolates the output signal of the mode selector 702 to satisfy the
signaling protocol and to drive a subsequent power controller
ballast.
[0062] The logic within the laser controlled dimmer device 700 is
powered by internal source voltage output from a regulator 704,
which receives current from a power bus 718. Phototransistors 726
and 728 are adapted to receive illumination by a laser or other
light source. The counter 710 counts up or down depending on which
phototransistor 726 and 728 is turned on. The digital-to-analog
converter 708 converts the count to an analog voltage signal (e.g.,
0 to 12 volts DC). The output of the digital-to-analog converter is
fed to an error amplifier 716.
[0063] The photometer component 714 may include two
phototransistors 724 and phototransistor 730 to provide an analog
voltage to the terminal of an error amplifier 716. The
phototransistor 724 monitors the ambient light around the laser
controlled dimmer device 700. The phototransistor 730 that is
masked from receiving light monitors the ambient temperature around
the laser controlled dimmer device 700. The output of the
photometer component 714 monitors the ambient illumination of a
given area and produces an analog voltage, which is also fed into
the error amplifier 716. The resulting voltage from the error
amplifier 716 is the difference between the voltage signal level
from the digital-to-analog converter 708, which sets a reference
voltage, and the output voltage of the phototransistor circuits.
The output of the error amplifier 716 is provided as an analog
input signal to the mode selector 702.
[0064] An input port 722 is adapted to receive a second input
signal to a mode selector 702. Using the input port 722, a
preceding mode selector, user-controlled voltage selector, or other
control device, may be coupled to the laser controlled dimmer
device 700 to configure a power controller network. Depending on
the mode selector setting in the mode selector 702, the input
voltage generated by the error amplifier 716 may be conducted to
the output port 720 of the laser controlled dimmer 700 to control
ballast or to provide an input signal to a subsequent mode
selector. In an alternative mode setting, the control signal
received by the input port 722 may be conducted to the output port
720 of the laser controlled dimmer device 700.
[0065] One application of a laser controlled dimmer device allows a
building operator to manipulate the dimmer device from a
considerable distance. For example, a conventional low powered
laser beam may be directed by a building operator to excite one of
the phototransistors 726 or 728. This control method is useful to
control a laser controlled dimmer device that is mounted on a high
ceiling or on some other location to which physical access is
limited or inconvenient. Furthermore, the photometer component 714
acts as an ambient light harvester (or "daylight harvester") that
will automatically adjust the output signal of the error amplifier
716 in accordance with the referenced voltage signal provided from
the digital-to-analog converter 708 to provide more or less light
as needed, depending on the ambient light level of the illumination
area. A display component 706 may display useful information, such
as the relative illumination level, the reference voltage level,
the ambient light level, and/or an indication that a laser light is
being detected by one of the transistors 726 and 728.
[0066] FIG. 8 depicts an exemplary logical representation for an
embodiment of the present invention that includes a communications
interface as a controlled voltage selector. A communications
interface device 800 includes a communications interface component
806, and a mode selector 802. A buffer 812 amplifies and isolates
the output signal of the mode selector 802 to satisfy the signaling
protocol and to drive a subsequent power controller or ballast. The
logic within the communications interface device 800 is powered by
internal source voltage output from a regulator 804, which receives
current from a power bus 818. The input signal to the
communications interface component 806 satisfies a digital
communications protocol in an embodiment to the present invention.
The communications protocol includes digital command signals
designed to allow at least one of the following: (1) On/off control
of downstream, i.e., subsequent, devices; (2) dimming of the
downstream devices; and (3) generation of a status signal from the
devices downstream. In an embodiment of the present invention, a
digital control signal includes an address (or identifier) and a
digital value representing a voltage level.
[0067] In an embodiment to the present invention, the
communications interface device 800 is individually addressable. A
microcontroller 814 may be set to accept at least one of 65000
unique addresses. In alternative embodiments, other addressing
means and a different number of unique addresses is contemplated
within the scope of the present invention. Using addressing,
individual ballasts or zones may be controlled from a master
digital controller, such as a computer or dedicated control
unit.
[0068] A UART (Universal Asynchronous Receiver-Transmitter) 816
handles asynchronous serial communications of digital commands from
the master digital controller. The output of the UART is received
by the microcontroller 814, which determines whether the digital
command signal received from the digital control system was
intended for the given communications interface device, in
accordance with its address setting. The counter 810 counts up or
down, according to the digital input signal. The output of the
counter is set to a digital-to-analog converter, where an analog
voltage of 0 to 12 volts DC is generated. Note that alternative
analog signaling protocols are contemplated within the scope of the
present invention. Furthermore, in alternative embodiments of the
present invention, the addressability of communications interface
devices may be omitted without departing from the scope of the
present invention.
[0069] In yet another embodiment of the present invention, a
digital signal on signal line 824 may be sent directly to the mode
selector 802 to control the mode selector or to provide an
alternate input signal. In such an embodiment, the mode selector
802 includes its own digital-to-analog converter logic to couple
into the mode selector circuitry.
[0070] An input port 822 is adapted to receive a second input
signal to the mode selector 802. Using the input port 822, a
preceding mode selector, user-controlled voltage selector, or other
control device may be coupled to the communications interface
device 800 to configure a power controller network. Depending on
the mode selector setting in the mode selector 802, the input
voltage generated by the digital-to-analog converter 808 may be
conducted to the output port 820 of the communications interface
device 800 to control a ballast or to provide an input signal to a
subsequent mode selector. In an alternate mode setting, the control
signal received via the input port 822 may be conducted to the
output port 820 of the communications interface device 800.
[0071] In another embodiment of the invention, the power controller
might simply be a micro-controller to digitally perform the various
operations discussed in all the above embodiments for the power
controllers. The micro-controller would have at least some working
memory, a non-volatile memory to store program instructions for the
operations to be performed, an input/output port and a system bus
to connect these components. The input signal lines would be
connected from the first and second input ports of the power
controller to analog-to-digital (A/D) converters. The control
signals as digital output of the A/D converters would be passed to
I/O port of the micro-controller. The micro-processor is programmed
to perform the various operations in the above embodiments. The
digital control signal computed by the microprocessor would be
passed to a digital-to-analog converter to produce the output
analog control signal for the output port of the power controller.
The mode input may be a local digital switch input to the
microprocessor or a separate digital input through the input/output
port of the microprocessor.
[0072] FIG. 9 illustrates a flow diagram for networking a power
controller that controls at least one ballast driving a lighting
device. In coupling operation 900, the output of a first power
controller is coupled to one of the input of a second power
controller to provide a power controller network. The input and
output signals of the power controllers are compatible (i.e.,
satisfy the same signaling protocol) so that a control signal
output from the first power controller can be used as an input
signal of the second power controller. Furthermore, the signaling
protocol is preferably designed to control a lighting ballast,
although other signaling protocols are contemplated within the
scope of the present invention.
[0073] In coupling operation 902, a user controlled voltage
selection device is coupled to another input of the power
controller. As discussed, a user-controlled voltage selection
device may include without limitation a rotary dimmer control, a
digital slide dimmer control, a keypad, a demand load shedder, a
laser-controlled dimmer device, a photometer, and a communications
interface to a digital controller.
[0074] Operation 904 selects one mode of a plurality of selection
modes, wherein the modes determine which input signal is to be
conducted to the output of the power controller. Each mode is
associated with a criterion, such as "Input A is conducted to
Output", "Input B is conducted to Output", "The higher level input
signal is conducted to Output", "The lower level input signal is
conducted to Output". Other criteria are also contemplated within
the scope of the present invention. Operation 906 conducts the
appropriate input signal to the output port in accordance with the
selected mode. Operation 908 controls a lighting ballast with the
output control signal, such as to decrease or increase the
illumination of the gas discharge lamp.
[0075] The embodiments of the invention described herein are
implemented as logical steps in one or more computer systems. The
logical operations of the present invention are implemented (1) as
a sequence of processor-implemented steps or program modules
executing in one or more computer systems and (2) as interconnected
machine modules or logic modules within one or more computer
systems. The implementation is a matter of choice, dependent on the
performance requirements of the computer system implementing the
invention. Accordingly, the logical operations making up the
embodiments of the invention described herein are referred to
variously as operations, steps, objects, or modules.
[0076] The above specification, examples and data provide a
complete description of the structure and use of embodiments of the
invention. Since many embodiments of the invention can be made
without departing from the spirit and scope of the invention, the
invention resides in the claims hereinafter appended.
* * * * *