USOO7566987B2
`
`(12) United States Patent
`US 7,566,987 B2
`(10) Patent N0.:
`Black et a].
`
`(45) Date of Patent: Jul. 28, 2009
`
`(54)
`
`NIETHOD OF POWERING UP A PLURALITY
`0F LOADS IN SEQUENCE
`
`5,734,230 A
`5,910,689 A
`
`3/1998 Edwards
`6/1999 Eitz, III et a1.
`
`(75)
`
`Inventors:
`
`Ricllard L. Black, Gilbertsville, PA
`(US); Joel Hnatow, Bethlehem, PA
`(US); Neil Orchowski, Philadelphia, PA
`(US); Jason P. Petrella, Center Valley,
`PA (US); Brian R. Valenta, Macungie,
`PA (US)
`
`(73)
`
`Assignee:
`
`Lutron Electronics Co., Inc.,
`Coopersburg, PA (US)
`
`<*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 193 days.
`
`(21)
`
`Appl. N0.: 11/900,855
`
`(22)
`
`Filed:
`
`Sep. 13, 2007
`
`(65)
`
`Prior Publication Data
`
`(Continued)
`FOREIGN PATENT DOCUMENTS
`
`EP
`
`0220504 A2
`
`5/1987
`
`(Continued)
`OTHER PUBLICATIONS
`
`Lutron Application Note #106, Emergency Lighting Systems, 2003,
`Lutron Electronics, Co. Inc, 10 pages.
`
`Primary ExamineriAlbert W Paladini
`Assistant ExamineriMichael Rutland Wallis
`(74) Attorney, Agem, or FirmiWoodcock Washhurn LLP
`
`US 2008/0067871 A1
`
`Mar. 20, 2008
`
`(57)
`
`ABSTRACT
`
`Related U.S. Application Data
`
`Provisional application No. 60/844,602, filed on Sep.
`14, 2006.
`
`Int. Cl.
`
`(2006.01)
`H02] 3/00
`(2006.01)
`G06F 1/00
`U.S. Cl.
`......................................... 307/41; 713/330
`Field of Classification Search ................... 307/41:
`713/300
`
`See application file for complete search history.
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,056,757 A
`4,593,349 A *
`4,799,039 A
`5,119,014 A
`5,237,207 A
`
`11/1977 lVIallCh et 211.
`6/1986 Chase et a1.
`1/1989 Balcom et a1.
`6/1992 Kronberg
`8/1993 Kwiatkowski et al.
`
`................ 713/330
`
`Power distribution systems that have a limited peak power
`capability or a high source impedance, such as site supply
`generators, are often susceptible to abnormal operation in
`response to the current drawn at power up from the loads
`connectcd to thc power distribution system. The prcscnt
`invention provides a lighting control system operable to
`power up a plurality of the lighting loads in sequence to
`reduce stress on the power distribution system. The lighting
`loads are each turned on as part of a startup sequence at
`predetermined times after an output voltage of the power
`distribution system has stabilized. The lighting control sys-
`tem is operable to begin the startup sequence in response to
`receiving a control signal representative that the power dis-
`tribution system has stabilized. The lighting loads are each
`controlled by a lighting control module, which is operable to
`wait for a predetermined amount of time for the startup
`sequence to begin before turning on the lighting loads.
`
`25 Claims, 13 Drawing Sheets
`
`
`
`
`t
`
`M2A¥ © ,
`LCM
`(A.,
`
`114
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Page 1 of 23
`
`VOLTSERVER EXHIBIT 1020
`
`Page 1 of 23
`
`VOLTSERVER EXHIBIT 1020
`
`

`

`US 7,566,987 B2
`
`Page2
`
`U.S. PATENT DOCUMENTS
`
`11/1999 Ferenceeta1~
`7/2000 NewmanJretaL
`9/2000 Elwood
`6/2001 Bhargava
`4/2002 Newman, Jr. et al.
`
`59905635 A
`60915205 A
`6.119,469 A
`6.252,753 B1
`6.380692 B1
`
`6.429,706 B1*
`6528957 B1
`-
`6.803,;28 B2
`
`8/2002 Amin etaL ................. 327/143
`3/2003 Luchaco
`.
`10/2004 Balasubramanlam et al.
`
`
`4
`..... 507/66
`
`7/2005 Shetler 612111
`6,917,124 B2*
`8/2005 WalkoJretal,
`6927547 B2
`8/2007 Hausman, Jr. et 31.
`7.259,524 B2
`7.278,036 B2* 10/2007 Yuan .......................... 713/300
`
`2002/0175641 A1
`2003/0105984 A1
`2004/0124710 A1
`2005/0057875 A1
`2005/0134121 A1
`
`11/2002 Andersen
`6/2003 Masuyama etal.
`7/2004 Pfeiffer
`3/2005 Kovcr. Jr. elal.
`6/2005 Lalhropelal.
`
`FOREIGN PATENT DOCUMENTS
`
`EP
`EP
`FR
`wo
`
`0300 091 B1
`1271745 A1
`1544977 A2
`2217844
`WO 92/04753
`
`”989
`/
`1/2003
`,
`6/2005
`““974
`3,1992
`
`* cited by examiner
`
`Page 2 of 23
`
`Page 2 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 1 of 13
`
`US 7,566,987 B2
`
`
`
`Fig. 1
`
`1 38
`
`
`116
`
`Power Panel
`
`
`
`136
`
`
`Processor
`
`
`
`121
`
`
`
`
`
`Page 3 of 23
`
`Page 3 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 2 of 13
`
`US 7,566,987 B2
`
`«“69:0
`
`6:8083
`
`m:85
`
`6:8083
`
`m:85
`
`6:8033
`
`v28:0
`
`wvN
`
`
`
`.558CNN
`
`m:_ww20-eoN
`
`66st
`
`
`
`6380522:was;
`
`cgumwcmano
`
`_
`
`w6:5033
`
`Sm
`
`
`
`56m
`
`IwLI
`
`
`
` N:$2626261EUllllll
`
`w:xcj6:50
`
`EN
`
`:85
`
`N.9m
`
`.02Emma
`
`Egon.o._.
`
`5255
`
`
`
`NNN
`
`3N
`
`
`
`2&5Egon.
`
`
`
`Page 4 of 23
`
`Page 4 of 23
`
`
`
`
`
`
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 3 of 13
`
`US 7,566,987 B2
`
`Enable startup
`sequence
`
`312
`
`300
`
`310
`
`
`314
`
`Select CCI
`
`
`timeout period
`
`Select CCI
`to respond
`
`316
`
`Select panel
`to turn on
`
`320
`
`Select time
`
`to turn on
`selected panel
`
`Fig. 3A
`
`322
`
`Page 5 of 23
`
`Page 5 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 4 of 13
`
`US 7,566,987 B2
`
`
`
`
`:n Homgvvgcul; IlluArr‘liha’tiérrIrl’ éfigcle < 8 series,HDF‘] - [Programming]
`flflle flewflaporis help
`§\
`
`............................................................... I
`-11
`I
`I
`I
`
`If closure Is not pruvrdad, proceed wrlh normal operallon at Wm \
`x
`‘;
`Inmallzallon Programming
`.
`.
`,
`r
`
`336
`§
`
`Select 3 Gel to enable Startup Sequencer.
`www.mmm ..........
`§Areallfioom 1\Panel 1 H8P5-120\Onboard COM
`
`0 Post Upload
`Post Upload prugramming is
`executed immedlately after the last
`lile is uploaded
`
`0 Processor Puwer Up
`Processor Power Up programming
`is executed immediately after the
`pruuessor is power on.
`
`© Slart Sequencer
`Starlup Sequencer programming ls
`executed lmmediately afier a
`closure is provided to the
`designaled onboard CCI.
`
`
`
`
`
`
`“weave“\m\xxxxx\u\\«<x<<«\«mmm -
`
`u
`
`-
`
`~
`
`-
`
`........
`
`”.1
`"J.
`
`
`
`332
`
`FIGBB
`
`330
`
`Page 6 of 23
`
`Page 6 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 5 of 13
`
`US 7,566,987 B2
`
`ner
`
`4’10
`
`.
`Flg- 4
`
`Sample
`CCI 138
`
`CCI asserted?
`
`No
`
`Yes
`
`428
`
`No
`
`400
`
`.
`
`
`
`_
`-
`
`
`.tate —
`CCI state —
`“asserted”?
`“unasserted”?
`
`
` Store
`Store "asserted"
`"unasserted” as
`as CCI state in
`
`Yes
`
`436
`
`memory
`
`
`
`CCI state in
`
`memory
`
`
`
`426
`
`Page 7 of 23
`
`Page 7 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 6 of 13
`
`US 7,566,987 B2
`
`Start CCI timer
`
`
` No 4
` Starlup
`Yes
`sequence
`
`- nabled’?
`
`500
`
`515
`
`
`
`
`state change to
`
`
`
`CCI timeout
`Control loads to
`
`normal levels
`
`expired?
`
`
`
`
`Starttfrfgfence
`
`522
`
`528
`
`Turn off
`
`
`loads 114
`
`all lighting
`
`
`
`ime for next
`
`event? Turn on next load
`
`
`
`520
`
`Yes
`
`
`
`state change to
`
`
`
`
`
`Fig. 5
`
`
`
`Page 8 of 23
`
`Page 8 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 7 of 13
`
`US 7,566,987 B2
`
`
`No
`
`
`
`Receive
`digital signal?
`
`
`Yes
`
`610
`
`612
`
`614
`
` No
`
`onfiguration
`signal?
`
`Yes
`
`616
`
`N0
`
`
` Enable
`startup-delay
`
`mode?
`Yes
`
`624
`
`600
`
`622
`
`Set startup-delay
`
`mode bit to zero
`
`in memory
`
`Process received
`digital signal
`appropriately
`
`
`
`Set startup-delay
`mode bit to one in
`memory
`
`518
`
`
`o
`
`0
`
`620
`
`Fig. 6
`
`Page 9 of 23
`
`Page 9 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 8 of 13
`
`US 7,566,987 B2
`
`710
`
`Begin
`startup timer
`
`Maintain controll-
`
`ably conductive
`device off
`
`
`
`
`
`
`
`No
`
`
`tartup-delay
`. ode enabled?
`
`
`
`Receive
`
`command?
`tartup-delay
`timeout?
`
`
`
`
`
`
`
`Control lighting
`Control lighting
`loads 114 in
`loads 114 to last
`
`
`known states
`response
`
`
`
`
` Receive
`command?
`
`Control lighting
`loads 114 to
`
`bypass mode
`
`Control lighting
`loads 114 in
`
`
`
`
`
`
`response
`
`
`700 J
`
`Page 10 of 23
`
`Page 10 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 9 0f 13
`
`US 7,566,987 B2
`
`8.
`
`525m
`
`
`
`Egon.530m3ob
`
`
`
`00:_m:mn_
`
`Oomm
`
`mo:65$8%<0:3%;
`
`<omw
`
`<5
`
`53.891
`
`5382;
`
`
`
`m5
`
`rm?
`
`9.:
`
`mogo>
`
`93%
`
`«385
`
`LGN‘—
`
`JOIBIGUGE)
`
`Page 11 of 23
`
`Page 11 of 23
`
`
`
`
`
`
`
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 10 of 13
`
`US 7,566,987 B2
`
`Start CCI timer
`
`No
` Startup
`
`Yes
`sequence
`
`- nabled’?
`
`
`
`
`
`
`
`state change to
`
`
`
`
`CCl timeout
`
`expired?
`
`515
`
`
`
`850
`
`(4
`
`518
`
`Control loads to
`
`
`
`normal levels
`
`Turn off
`
`all lighting
`loads 114
`
`
`Yes
`
`516
`
`Transmit 00!
`status message
`
`Start sequence
`timer
`
`
`
`
`
`Turn on next load
`
`ime for next
`event?
`
`N0
`
`Fig. SB
`
`Page 12 of 23
`
`Page 12 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 11 of 13
`
`US 7,566,987 B2
`
`862
`
`eceive
`
`CCI request
`: essage?
`
`
`Transmit CCI
`status message
`
`
`
`
`
`864
`
`866
`
`860
`
`
`
`
`872
`
`eceive
`
`CCI status
`
`874
`
`- essage'7
`
`No
`
`status message =
`
`
`
`
`“asserted”
`
`
`CCI state =
`
`
`“unasserted”
`
`
`
`CCI state =
`
`A Store
`Store ”asserted"
`
`“unasserted” as
`.
`
`CCI state in
`as CCI state m
`870
`memory
`memory
`
`Page 13 of 23
`
`Page 13 of 23
`
`

`

`US. Patent
`
`Jul. 28, 2009
`
`Sheet 12 of 13
`
`US 7,566,987 B2
`
`/\
`
`890
`
`892
`
`510
`
`
`
`
`Startup
`
`
`Transmit CCI
`sequence
`request message
`Start CCI timer
`
`
`
`- nabled’)
`
`515
`
`
`
`No
`
`CCI timeout
`
`
`
`state change to
`
`
`
`expired?
`
`Yes
`
`516
`
`524
`
`518
`
`
`
`Start sequence
`timer
`
`522
`
`528
`
`Turn off
`
`loads 114
`
`all lightlng
`
`Turn on next load
`
`
`
`Yes
`
`
`
`ime for next
`event?
`
`
`
`
`
`Control loads to
`normal levels
`
`
`
`530
`
`
`
`Yes
`
`Page 14 of 23
`
`Fig. 8E
`
`Page 14 of 23
`
`

`

`US. Patent
`
`Jul 28, 2009
`
`h
`
`0
`
`6
`
`2B
`
`7lma9“.
`
`3_1_m_
`
`6III5,1IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIJ_7_S_O_U_..N9.1........J_____max/15“ucg_mm§o>EuA__B8__E25mm,m3"mm1Lf_
`sE
`
`w:v:km:of
`
`
`
`.23.20...204
`
`05o;
`
`
`o;.3%m:mm§o>
`‘N;am_mm2:
`
`Page 15 of 23
`
`Page 15 of 23
`
`
`

`

`US 7,566,987 B2
`
`1
`lVIETHOD OF POWERING UP A PLURALITY
`OF LOADS 1N SEQUENCE
`
`RELATED APPLICATIONS
`
`This application claims priority from commonly—assigned
`US. Provisional Application Ser. I\o. 60/844,602, filed Sep.
`14, 2006, entitled METHOD OF STARTING UP A PLU-
`
`RALITY OF LOADS IN SEQUENCE, the entire disclosure
`of which is hereby incorporated by reference.
`
`BACKGROUND OF THE INVENTION
`
`
`
`The present application is related to commonly-assigned,
`co-pending US patent applications Nos. 11/900,717 and
`11/900,900, each of which was filed on Sep. 13, 2007. The
`entire disclosures of both applications are hereby incorpo-
`rated by reference.
`1. Field of the Invention
`The present invention relates to a lighting control system
`comprising a plurality of load control devices for controlling
`the amount of power delivered to an electrical load from a
`power distribution system, and more particularly, to a lighting
`control system operable to power up the plurality of load
`control devices in a sequence to reduce stress on the power
`distribution system at an initial powcr up.
`2. Description of the Related Art
`Power distribution systems are often susceptible to abnor-
`mal operation in response to the current drawn from the loads
`connected to the power distribution system. For example, if
`all of the loads connected to the power distribution system
`power up concurrently and draw a large electrical current
`from the power distribution system, the magnitude and fre—
`quency of the output voltage ofthe power distribution system
`may fluctuate causing undesired responses in the operation of
`the loads.
`
`The abnormal operation of a power distribution system is
`commonly brought about by two characteristics of the power
`distribution system. First, the power distribution system may
`have a limited peak power capability. Ifthe power distribution
`system is subject to a pulse of load current having a magni-
`tude that exceeds the peak power capability, fluctuations may
`occur in the output voltage of the power distribution system.
`For example, site supply generators have a substantially lim-
`ited peak power capability as compared to utility-based gen-
`eration. However, site supply generators are often used as the
`power distribution systems on marine vessels, such as yachts
`and cruise ships, and as backup power sources (i.e., inthe case
`of a utility power outage).
`Further, power distribution systems having a high source
`impedance are more susceptible to abnormal output perfor-
`mance. For example, if a residence (i.e., a utilization point) is
`located a long distance from an electricity generating plant
`(i.e., a generation point), there is typically a large impedance
`between the utilization point and the generation point because
`of the large resistance of the electrical wire between the
`residence and the generating plant. Accordingly, the output
`voltage provided to the residence by the power distribution
`system is more susceptible to fluctuations in the line voltage
`in response to changes in the load current. The type and size
`oftransformers and conductors used in the power distribution
`system (such as a generator) may also contribute to a high
`source impedancc.
`A typical load of a power distribution system is a lighting
`control system, which may comprise a large number of light-
`ing loads that are controlled from, for example, a plurality of
`load control modules located in power panels. The lighting
`
`Page 16 of 23
`
`2
`control system may also comprise a central processor for
`control of the load control modules. Prior art lighting control
`systems have operated to turn the lighting loads on at once
`upon power up, i.e., when the lighting control system is
`energized. Typically, the lighting loads are turned on to the
`last lighting intensity, i.e., the lighting intensity that the light-
`ing load was illuminated to before the power was removed
`from the system. A typical
`lighting control system is
`described in greater detail in US. Pat. No. 6,803,728, issued
`Oct. 12, 2004, entitled SYSTEM FOR CONTROL OF
`DEVICES, the entire disclosure ofwhich is hereby incorpo-
`rated by reference.
`When a lighting load is first tumed on, the lighting load
`may draw a substantially large inrush current. Accordingly, if
`the power distribution system powering the lighting control
`system is susceptible to abnormal operation as described
`above, the power distribution system may not be able to
`provide the appropriate power to start up the lighting control
`system when the lighting control system is energized such
`that all of the lighting loads turn on at once. This may occur,
`for example, when a backup generator powers up in response
`to a power outage.
`Further, a situation may occur in which the output voltage
`of the generator fluctuates as the lighting control system and
`all other loads powered by the generator attempts to power up
`at once. When the generator first powers up, the generator
`produces an output voltage having a maximum magnitude.
`After being energized by the output voltage of the generator,
`the central processor of the lighting control system tunis on
`the lighting loads. The lighting control system may then draw
`a substantially large inrush current from the generator. If the
`generator is not able to provide the amount of current required
`by the large inrush current, the output voltage ofthe generator
`decreases in magnitude. Ifthe output voltage of the generator
`drops to a magnitude that is too low to power the lighting
`control system (i.e., a magnitude at which the internal power
`supplies of the components of the lighting control system
`drop out), the lighting control system turns all of the lighting
`loads off and stops drawing a significant amount of current
`from the power distribution system. Since the generator is no
`longer overloaded,
`the output voltage of the generator
`increases in magnitude. Accordingly, the lighting control sys-
`tem powers up, thus, tuming all ofthe lighting loads on again,
`and the cycle repeats.
`Therefore, there is a need for a lighting control system that
`is operable to start up without over-stressing a power distri-
`bution system with a limited peak power capability or a high
`source impedance.
`
`SUMMARY OF THE INVENTION
`
`According to the present invention, a method ofcontrolling
`the amount ofpower delivered to aplurality ofelectrical loads
`from a power distribution systcm in ordcr to prevent abnormal
`operation of the power distribution system is provided. The
`method comprises the step of sequentially powering up each
`of the plurality of loads. Preferably, the step of sequentially
`powering up each of the plurality of loads comprises power-
`ing up a first one of the plurality of loads at a first time, and
`powering up a second one of the plurality of loads at a second
`time different than the first time. The method may further
`comprise the steps of providing a control signal from the
`power distribution system in response to the power distribu-
`tion system stabilizing, and sequentially powering up each of
`the plurality of loads at predetermined times in response to the
`step of providing a control signal.
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`Page 16 of 23
`
`

`

`US 7,566,987 B2
`
`3
`In addition, the present invention provides a load control
`system for controlling the amount of power delivered to a
`plurality of electrical loads from a power distribution system.
`The load control system comprises a plurality of load control
`devices. Each load control device is coupled to one of the
`plurality of electrical loads. The load control devices are
`operable to turn on each of the electrical loads in sequence in
`response to the AC power source powering up to prevent
`abnormal operation of the power distribution system.
`Other features and advantages ofthe present invention will
`become apparent from the following description ofthe inven-
`tion that refers to the accompanying drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`F G. 1 is a simplified block diagram of a centralized light-
`ing control system according to a first embodiment of the
`present invention;
`F G. 2 is a simplified block diagram ofthe lighting control
`mocule of the lighting control system of FIG. 1;
`F G. 3A is a simplified flowchart ofan example of a startup
`sequence configuration procedure executed by a user of the
`GUI software ofa PC ofthe lighting control system of FIG. 1;
`F G. 3B is an example screen shot of a startup sequence
`configuration screen of the startup sequence configuration
`proccdurc of FIG. 3A;
`F G. 4 is a simplified flowchart of a CCI procedure
`executed by a central processor ofthe lighting control system
`of FIG. 1;
`F G. 5 is a simplified flowchart of a startup procedure
`executed by the central processor of the lighting control sys-
`tem of FIG. 1;
`F G. 6 is a simplified flowchart of a communication pro—
`cedure executed by a microprocessor of the lighting control
`mocule of FIG. 2;
`F G. 7 is a simplified flowchart of a startup procedure
`executed by the microprocessor of the lighting control mod—
`ule of FIG. 2;
`F G. 8A is a simplified block diagram of a centralized
`ligh ing control system according to a second embodiment of
`the present invention;
`F G. 8B is a simplified flowchart ofa first startup procedure
`executed upon power up by a first central processor of the
`ligh ing control system ofFIG. 8A;
`F G. 8C is a simplified flowchart of a first communication
`procedure executed periodically by the first central processor
`of the lighting control system of FIG. 8A;
`F G. 8D is a simplified flowchart of a second communica—
`tion procedure executed periodically by central processors
`other than the first central processor of the lighting control
`system of FIG. 8A;
`F G. SE is a simplified flowchart of a second startup pro-
`cedure executed upon power up by the central processors
`other than the first central processor of the lighting control
`system of FIG. 8A; and
`F G. 9 is a simplified block diagram of a distributed light-
`ing control system according to a third embodiment of the
`present invention.
`
`
`
`
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`The foregoing summary, as well as the following detailed
`description of the preferred embodiments, is better under-
`stood when read in conjunction with the appended drawings.
`For the purposes of illustrating the invention, there is shown
`in the drawings an embodiment that is presently preferred, in
`which like numerals represent similar parts throughout the
`
`10
`
`15
`
`20
`
`30
`
`35
`
`40
`
`45
`
`60
`
`65
`
`4
`several views of the drawings, it being understood, however,
`that the invention is not limited to the specific methods and
`instrumentalities disclosed.
`FIG. 1 is a simplified block diagram of a centralized light-
`ing control system 100 according to a first embodiment ofthe
`present invention. The lighting control system comprises a
`power panel 110 having a plurality of load control modules
`(LCMs) 112 (i.e., a load control device). Each load control
`module 112 is coupled to a lighting load 114 for control ofthe
`amount ofpower delivered to the lighting load. Alternatively,
`each load control module 112 may be coupled to more than
`one lighting load 114, for example, four lighting loads, for
`individually controlling the amount of power delivered to
`each of thc lighting loads. Thc powcr pancl 110 also com-
`prises a module interface (MI) 116, which controls the opera-
`tion of the load control modules 112 via digital signals trans-
`mitted across a power module control link 118.
`A power distribution system 120 provides an output volt-
`age (i.e., a line voltage, such as 120 V, 60 Hz) to the load
`control modules 112 via two line voltage connections 121.
`While not shown in FIG. 1, each load control module 112
`directly receives the output voltage from the power distribu-
`tion system 120. The power distribution system 120 com-
`prises a first power source 122 (e.g., an external power gen-
`erating plant), a transfcr switch 124, and an on-sitc supply
`generator 125. The transfer switch 124 is typically in position
`A, such that the lighting control system 100 is powered by the
`first power source 122 in normal operation. However, in the
`event of a power outage, i.e., if the first power source 122
`cannot supply power to the lighting control system 100, the
`transfer switch 124 changes to position B, such that the gen-
`erator 125 powers the lighting control system. Since the gen—
`erator 125 may have a limited peak power capability and a
`high source impedance, the generator 125 may be susceptible
`to abnormal operation in response to large pulses of load
`current drawn by the lighting control system 100.
`The power distribution system 120 further comprises a
`sense circuit 126 for generating apower system output signal,
`e.g., a contact closure output (CCO) signal 128. The contact
`closure output signal 128 is generated by a suitable switching
`device (not shown) in the sense circuit 126, such as, for
`example, a relay or a transistor. The switching device has two
`states (i.e., open or closed), such that the contact closure
`output signal 128 is asserted by closing the switching device,
`i.e., electrically connecting the two terminals of the switching
`device. Preferably, the contact closure output signal 128 is
`asserted (i.e., closed) when the output voltage ofthe generator
`125 is stable, i.e., not fluctuating, and is not asserted (i.e.,
`open) when the output voltage of the generator 125 is not
`stable. Alternatively, the contact closure output signal 128
`may be asserted when the output voltage of the generator 125
`is not stable. Further, the power system output signal may
`comprise any suitable control signal rather than the contact
`closure output signal 128.
`Thc lighting control systcm 100 furthcrcompriscs a ccntral
`processor 130, which controls the operation of the lighting
`control system, specifically, the amount of power delivered to
`the lighting loads 114 by the load control modules 112. The
`central processor 130 is operable to communicate with the
`module interface 116 of the power panel 110 via an MI link
`132. Accordingly, the module interface 116 is operable to
`cause the load control modules 112 to turn off and on and to
`control the intensity of the lighting loads 114 in response to
`digital signals received by the module interface 116 from the
`central processor 130.
`FIG. 2 is a simplified block diagram ofthe lighting control
`module 112. The lighting control module 112, as shown in
`
`Page 17 of 23
`
`Page 17 of 23
`
`

`

`US 7,566,987 B2
`
`5
`FIG, 2, comprises four load control circuits 210. Each load
`control circuit 210 is coupled to a lighting load 114 for control
`of the intensity of the lighting load. The load control module
`112 is coupled to the line voltage connections 121 of the
`power distribution system 120 via a hot terminal H and a
`neutral terminal N. An air—gap switch, e.g., a relay 212, is
`coupled to the hot terminal II to provide a switched hot
`voltage SH for the load control circuits 210. The load control
`circuits 210 and the relay 212 are controlled by a micropro-
`cessor 214. The microprocessor 214 may be any suitable
`controller, such as a programmable logic device (PLD), a
`microcontroller, or an application specific integrated circuit
`(ASIC). The microprocessor 214 is coupled to a non-volatile
`memory 215 for storage of data regarding the operation ofthe
`lighting control module 112.
`The load control module 112 is coupled to the power mod-
`ule control link 118 to receive digital control signals from the
`module interface 116 Via a communication circuit 216. The
`communication circuit 216 is coupled to the microprocessor
`214, such that the microprocessor is operable to control the
`load control circuits 210 in response to the digital control
`signals transmitted by the module interface 116. A power
`supply 218 is coupled between the hot terminal H and the
`neutral terminal N and generates a direct-current (DC) volt-
`age VCC for powering the microprocessor 214, the commu-
`nication circuit 216, and the other low-voltage circuitry ofthe
`load control module 112.
`Each load control circuit 210 uses one ormore controllably
`conductive devices (not shown), for example, relays or bidi-
`rectional semiconductor switches, such as triacs or field-
`effeet transistors (FETs), to control the amount of power
`delivered to the lighting load 114. The controllably conduc—
`tive device is coupled in series between the switched hot
`voltage SH and the lighting load 114. Using a phase-control
`dimming technique, the microprocessor 214 causes the load
`control circuit 210 to render the controllably conductive
`device conductive for a portion of each half-cycle to provide
`power to the lighting load 114, and to render the controllably
`conductive device non-conductive for the other portion ofthe
`half—cycle to disconnect power from the lead 114. In forward
`phase-control dimming, the controllably conductive device is
`conductive at the end of each half-cycle, Altematively, in
`reverse-phase control dimming, the controllably conductive
`device is conductive at the beginning of each half-cycle.
`A zero-crossing detector 220 determines the zero-cross-
`ings of the line voltage of the power distribution system 120.
`A zero—crossing is defined as the time at which the line volt—
`age transitions from positive to negative polarity. or from
`negative to positive polarity, at the beginning of each half-
`cycle. The zero-crossing information is provided as an input
`to the microprocessor 214. The microprocessor 214 controls
`the controllably conductive devices of the load control cir-
`cuits 210 to provide line voltage to the lighting loads 114 at
`predetermined times relative to the zero-crossing points ofthe
`AC waveform using the standard phase-control dimming
`techniques.
`Since the generator 125 may produce some amount of
`noise on the line voltage ofthe power distribution system 120,
`the zero-crossing detector 220 preferably includes an active
`filter for receiving the line voltage, and for recovering the AC
`fundamental waveform. The recovered AC fundamental is
`
`preferably substantially free of noise or distortion, and of
`frequency components greater than at least second order har-
`monics, that may be present on the line voltage of the power
`distribution system 100, and that might otherwise result in
`faulty or incorrect zero crossing detection. The filter may take
`an analog or digital (software) fonn and is described in
`
`10
`
`15
`
`20
`
`30
`
`35
`
`40
`
`45
`
`60
`
`65
`
`6
`greater detail in commonly-assigned US. Pat. No. 6,091,205,
`issued Jul. 18, 2000, and commonly-assigned U.S. Pat. No.
`6,380,692, issuedApr. 30, 2002, both entitled PHASE CON-
`TROLLED DIMMING SYSTEM WITH ACTIVE FILTER
`FOR PREVENTING FLICKERING AND UNDESIRED
`
`INTENSITY CHANGES. The entire disclosures of both pat—
`ents are hereby incorporated by reference.
`The lighting control module 112 may optionally comprise
`a voltage compensation circuit 222. The voltage compensa-
`tion circuit 222 is operable to integrate a signal representative
`of a square of an amplitude of the electrical waveform to
`produce a signal representative ofthe energy delivered to the
`lighting load 114 so far in the present half-cycle. If reverse
`phase-control dimming is being used, the microprocessor 214
`may use the signal generated by the voltage compensation
`circuit 222 to control the load control circuit 210 in response
`to the energy delivered to the lighting loads 114. The voltage
`compensation circuit 222 is described in greater detail in
`commonly-assigned co-pending US. patent application Ser.
`No. 10/865,083, filed Jun. 10, 2004, entitled APPARATUS
`AND METHODS FOR REGULATING DELIVERY OF
`
`ELECTRICAL ENERGY. the entire disclosure of which is
`hereby incorporated by reference.
`Referring back to FIG. 1, the central processor 130 may
`also be coupled to a personal computer (PC) 134 via a PC link
`136. The PC 134 executes a graphical user interface (GUI)
`software that allows a user of the lighting control system 100
`to setup and monitor the lighting control system. Typically,
`the GUI software creates a database defining the operation of
`the lighting control system 100 and the database is down-
`loaded to the central processor 130 via the PC link 136. The
`central processor 130 comprises a non—volatile memory for
`storing the database.
`The central processor 130 comprises a contact closure
`input (CCI) 138 for receipt of the contact closure output
`signal 128 from the sense circuit 126 ofthe power distribution
`system 120. The contact closure output signal 128 is repre-
`sentative of the output voltage of the generator 125 stabiliz-
`ing. Alternatively, the CCI 138 could be included as part of an
`extemal device, such as, for example, a contact closure input
`device coupled to the central processor 130 via a communi-
`cation link, such that the contact closure input device is oper-
`able to transmit a digital signal to the central processor in
`response to contact closure output signal 128.
`According to the present invention, the central processor
`130 is operable to startup the lighting loads 114 in a sequence
`(i.e., a startup sequence) when the contact closure output
`signal 128 is asserted (corresponding to the output voltage of
`the generator 125 stabilizing) within a first predetermined
`amount of time T1 after powering up. When the lighting
`control modules 110 are in a startup—delay mode, the lighting
`control modules do not power up the connected lighting loads
`114 immediately upon power up, but waits for a second
`predetermined amount oftime T2 to receive a command from
`the central processor 130.
`Using the GUI software executed by the PC 134, the user
`can enable the startup sequence, such that the lighting control
`system 100 is operable to respond to the contact closure
`output signal 128. The user may also program a schedule
`defining the startup sequence into the database of the lighting
`control system 100 using the GUI software. When the data-
`base is downloaded from the PC 134 to the central processor
`130, the central processor 130 saves the events of the startup
`sequence in memory and transmits an appropriate startup-
`delay configuration signal to the module interface 116 via the
`MI link 132. In response, the module interface 116 causes the
`lighting control modules 112 to set a startup-delay mode bit in
`
`Page 18 of 23
`
`Page 18 of 23
`
`

`

`US 7,566,987 B2
`
`7
`the memory of the microprocessor 214 to designate that the
`lighting control module 112 is in the startup-delay mode.
`When the central processor 130 is powered up and the
`startup sequence in enabled, the central processor waits (for
`the first predetermined amount of time T1) for the contact
`closure signal 128 to be asserted. The contact closure output
`signal 128 is asserted in response to the sense circuit 126
`determining that the output voltage of the generator 125 has
`stabilized. If the contact closure output signal 128 is asserted
`before the central processor 130 powers up, or after the cen—
`tral processor powers up. but before the first predetermined
`period of time T1 expires, the startup sequence is started by
`the central processor. Upon determining that the contact clo-
`sure output signal 128 is asscrtcd, thc ccntral processor 130
`immediately begins controlling all of the lighting loads 114
`off, i.e., the central processor does not turn any ofthe lighting
`loads on. Then, at the event times ofthe startup sequence, the
`central processor 130 controls each of the lighting loads 114
`on. The startup sequence may be programmed such that the
`lighting loads 114 are tumed on one by one. The startup
`sequence may also be programmed such that the lighting
`loads 114 are turned on in groups, for example, on a panel-
`by-panel basis. Preferably, emergency or necessary lighting
`may be turned on prior to tuming on non-essential lighting.
`If the contac