Note: Descriptions are shown in the official language in which they were submitted.
~ - 217211~
P/ 10-
Title: IMPROVED SYSTEM FOR INDIVIDUAL AND REMOTE
CONTROL OF SPACED LIGHTING FIXTURES
FIELD OF THE INVENTION
This invention relates to the remote control of
lighting fixtures, and more specifically relates to an
improved system and components therefor for the selective
control of overhead lighting fixtures by a hand-held
infrared radiation source, and is an improvement of the
system and components described in copending application
Serial No. , entitled REMOTE CONTROL SYSTEM FOR
INDIVIDUAL CONTROL OF SPACED LIGHTING FIXTURES and filed
on even date herewith, the subject matter of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
Prior known systems for remote control of
lighting fixtures are described in detail in the above-
noted copending application Serial No.
Thus, the lighting of spaces by a plurality of
spaced gas discharge lamps (for example, fluorescent
lamps), or incandescent lamps is well known. Commonly,
one or more fluorescent lamps are mounted in a fixture
with a ballast, and such fixtures are spaced over a
ceiling on four foot or eight foot centers. Similarly,
overhead fixtures for incandescent lamps may be mounted
on centers greater than about two feet. Such lamp
fixtures are commonly connected to a single power source
and are simultaneously turned on and off or, if provided
with dimming capability, are simultaneously dimmed.
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It is also known that such overhead fixtures
can be individually controlled or dimmed. For example,
in a given office space, one worker may prefer or need
more or less light intensity than another worker at a
spaced work area. Dimming systems are known for
selectively dimming the lamps of different fixtures to
suit the needs of individual workers. For example, each
fixture can be individually hard wired to its own
remotely mounted dimmer. However, the installation of
this wiring can be quite costly and the determination of
which dimmer controls which fixture may not be
immediately obvious to the user of the system.
Alternatively the dimmers could be located
within each fixture and controlled by signals sent over
low voltage wiring or through signals transmitted over
the line voltage wiring through a power line carrier
system. Unfortunately, both of these approaches require
expensive interfaces within each fixture to translate
and/or decode the received signals for control of the
dimmer.
In another known system, a dimmer with a
dimming adjustment control is provided at each fixture,
and that control is manually operated, for example by
rotating the control with a rigid pole long enough to
reach the fixture. In this way, each fixture can be
selectively adjusted. However, the system is
inconvenient to use and, once the fixture intensity is
set, it is difficult or inconvenient to readjust.
Moreover, it is difficult to retrofit an existing
installation with a control system of this nature.
A known fluorescent controller system is also
sold by Colortran Inc. of Burbank, CA, termed a "sector
fluorescent controller" in which an infrared receiver is
SPeC~1491 15
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mounted at a location spaced from its respective
fluorescent lamp fixture. Thus, the receiver is fixed to
a T-bar, on the wall, on a louver or is counter-sunk
flush with wall or ceiling. A ballast controller may be
mounted in the lighting fixture, in addition to a
conventional dimming ballast. Wiring is then run from
the external infrared receiver into the interior of the
fixture to the ballast controller. A hand-held remote
control infrared transmitter illuminates the infrared
receiver at one or more fixtures to control their dimming
level.
The need to run wiring from the external sensor
complicates the installation of such devices. Further,
since the sensor is spaced from the fixture, it requires
separate installation, and is visible to view. Moreover,
the infrared transmitter of the Colortran device has a
transmitting angle of 30. Therefore, several receivers
can be illuminated simultaneously, making selection of
control of only one fixture difficult unless the user
places himself in a precise location within the room
under the fixture to be controlled.
A similar system is sold by the Silvertown
Hitech Corporation, where the infrared receiver is
mounted to the louvers of a fluorescent fixture. In this
system, the infrared receiver is specifically adapted to
be mounted to a specific fluorescent fixture, and it
tends to block light output from the fixture.
A further system is sold by Matsushita wherein
a single transmitter can be used for independent control
of two or more different receivers. This is achieved by
adjusting a switch on the transmitter to correspond to a
switch setting which has been previously set at the
receiver corresponding to the fixture desired to be
SPEC\1491 15
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controlled. For example, fixture A could be controlled
when the switch is in position 1 and fixture B could be
controlled when the switch is in position 2. In this
system, the user must remember which fixture corresponds
to which switch position, i.e., A corresponds to 1 and B
corresponds to 2.
It is easy for the user to forget and become
confused, particularly when there are three or four
fixtures controlled by three or four switch positions.
This is an undesirable situation. Further, there is a
practical limitation on the number of switch positions
which can be provided and the number of fixtures in a
large room will exceed this. Additionally, there is a
great deal of work in programming and reprogramming the
receivers for a large number, for example, 20 fixtures.
In comparison with the system of the invention
of copending application Serial No. , as will
be described in more detail later, the transmitter is
simply pointed at the receiver in the fixture which it is
desired to control. This is simple, unambiguous and
transparently ergonomic. Further, it does not require
any preprogramming or reprogramming of the receiv
It is also known to use an infrared transmitter
for the control of a wall box mounted dimmer, such as the
"Grafik Eye" Preset Dimming Control sold by Lutron
Electronics Co., Inc., the assignee of the present
invention. Also see U.S. Patent 5,191,265 which
describes such transmitters. The Grafik Eye Dimmer
Control system provides for the remote control of
fixtures and other lamps by a control circuit located at
the wall box which controls those fixtures and lamps. An
infrared transmitter aimed at the wall box housing
produces a beam which contains information to turn on and
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off and to set the light dimming level of the fixtures
being controlled to one of a plurality of preset levels,
or to continuously increase or decrease the light level.
Other similar systems are sold by Lutron Electronics Co.,
Inc. under the trademark RanaX-Wireless Dimming Control
System. Such systems are not intended to control
individual ceiling fixtures in a room independently of
other closely spaced fixtures (those fixtures spaced up
to about two feet apart).
The invention of copending application Serial
No. solved the problems referred to above.
Thus, in accordance with that invention, each fixture to
be controlled has a radiation receiver and ballast
control circuit mounted in the interior of the fixture
housing and is wired internally of the fixture housing to
a dimming ballast in the case of a fluorescent fixture.
In the case of an incandescent fixture, each light to be
controlled has a radiation receiver and dimmer, which is
connected to the lamp to be controlled. A small opening
in the fixture housing allows optical communication with
the radiation receiver and is easily illuminated from
substantially any location in the room containing the
fixtures. A narrow beam radiation transmitter with a
beam angle, for example, of about 8 is employed to
illuminate the radiation-receiving opening in the fixture
without illuminating the fixtures spaced greater than
about two feet from the fixture to be controlled. For
rooms about thirty feet by thirty feet in area and ten
feet high, fixtures two feet apart can be easily
discriminated between one another. For larger spaces,
the user can reposition himself to discriminate between
closely spaced fixtures.
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The receiver is a novel structure containing a
printed circuit board mounted across a central area of a
typical back box. A radiation sensor is mounted on the
printed circuit board and faces an open side of the box
which is covered by a yoke. The radiation employed is
preferably infrared light and the yoke has an infrared
transparent portion to allow infrared radiation to reach
the radiation sensor. Narrowly focused, high frequency
ultrasound could also be employed.
In addition, either a visible or invisible
laser beam with information encoded on it in known manner
could be used, with the laser beam being spread by
optical means such as a divergent lens. In the case of a
visible beam, this would produce a beam like a flashlight
pointer which would aid in pointing the transmitter at
the receiver.
Finally, narrowly focused radio frequency waves
could be used. These could be emitted from a parabolic
reflector on the transmitter, using a parabolic reflector
of approximately 4.3 cm in diameter and a frequency of 60
GHz. The beam spread would be approximately 8. The
opening used for optical signals would, of course, be
modified if radio frequency waves are used.
To install the receiver structure of
application Serial No. , a novel mounting
structure is provided whereby a plastic hook and loop
type fastener surface is fixed to the yoke and a
cooperating hook and loop type surface is attached to the
interior of the fixture, preferably on the wire way cover
within the fixture. All wires can then be interconnected
within the fixture wire-way. An opening is formed in the
wire-way cover of the fixture and optically communicates
with the radiation receiver within the receiver housing.
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The receiver housing is easily located within the wire-
way housing to communicate with the opening in the wire-
way cover and is then pressed in place. An optical lens
insert can be installed in the yoke to assist in focusing
input radiation on the radiation receiver sensing
element. This lens insert can be interchangeable and
different lens inserts can be designed to have different
angles of acceptance of input radiation.
The lens protrudes slightly through an opening
in the fixture housing to receive infrared radiation from
the transmitter. The transmitter is an infrared
transmitter of the type employed in the Lutron Grafik Eye
system previously identified for use with wall box dimmer
systems. The Grafik Eye transmitter is an infrared
transmitter which transmits signals with twelve different
code combinations. The transmitter is operable to
transmit a beam angle of about 8 and can, therefore,
selectively illuminate relatively closely spaced ceiling
fixtures. Depending on the control which is activated, a
selected fixture can be dimmed to one of a plurality of
preset dim conditions, or can be dimmed continuously up
or down. Thus, the transmitter can accomplish
raise/lower, presets, low/high end trim and the like.
Alternatively, a transmitter with a movable slide or
rotary actuator could be used to provide continuous
dimming control.
This novel structure had a major advantage in
retrofitting an existing installation. Thus, it is only
necessary to drill a small opening in the wire-way cover,
and mount an infrared receiver/ballast controller to the
wire-way cover in line with the opening within the wire-
way cover. Light dimming ballasts are then mounted
within the fixture wire-way and are interconnected with
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the receiver/ballast controller within the fixture wire-
way without need for external wiring. The wire-way cover
with receiver/ballast controller attached is then
reinstalled in the fixture.
The previously described invention of
application Serial No. is also disclosed for
use with a large variety of existing fixtures and can
also be used with external switches and dimming circuits.
Photocells, occupancy sensors, time clocks, central relay
panels and other inputs can also be used with the novel
system. Furthermore, that invention made it possible for
a single receiver to operate any desired number of
ballasts.
The primary application of the invention of
application Serial No. is in large open plan
office areas illuminated by overhead fluorescent
fixtures, particularly where video display units (e.g.,
personal computers) are used. However, the invention
also has applications in areas which are used for audio
visual presentations, in hospitals and elder care
facilities, in manufacturing areas and in control rooms,
the control of security lighting either indoor or outdoor
and to reduce lighting levels for energy conservation.
A further application of the prior invention is
in wet or damp locations where normal wall controls
cannot be used due to the danger of electric shock or in
areas with hazardous atmospheres where there is a danger
of explosion if a line voltage wall control is operated
and causes a spark. In these cases, the receiver can be
located in a protected fixture and the lights controlled
by the low voltage hand-held remote control transmitter.
The prior invention was described with respect
to the control of light levels. However, the output from
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the receiver could be adapted in known manner to control
motor speed and/or position such as the position of the
motors in window shade control systems. The output from
the receiver could further be adapted to control other
types of actuators such as solenoids.
The above-described invention of application
Serial No. performs very well. However, it
has been found that the system was directionally
sensitive due to shadowing and unpredictable reflections
of the radiation by the light fixture baffle or lens. It
was also found that the system was sensitive to sources
of infrared radiation other than the infrared signal of
the remote transmitter, and further, that the system was
slow in responding to a valid infrared signal from the
transmitter because the receiver was waiting for a signal
while in an "insensitive" state.
A further problem with the system of
application Serial No. was that an expensive
fiber optic cable was required when the end of the IR
receiver was removed some distance, for example, up to 24
inches from the IR receiver housing.
BRIEF SUMMARY OF THE INVENTION
In accordance with a first feature of the
present invention, the radiation receiver extending from
the radiation receiver housing is an elongated radiation
conductor or antenna which has a length which is
sufficiently long that it extends from the fixture wire
way to which receiver is attached to a free end which is
flush with or penetrates beyond the plane of the fixture
reflector surface or lens cover. Thus, typical fixtures
employ parabolic or prismatic lens covers or baffle
structures which tend to shadow or block line-of-sight
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radiation from a location at an angle to a vertical from
the fixture. 8y elongating the radiation receiver, its
free end or tip is in or slightly beyond the outermost
plane of the fixture baffle structure so that the
radiation received by the end of the radiation receiver
is unaffected by shadowing or internal reflection within
the lens cover.
In one embodiment, the radiation receiver is a
thin, rigid, molded plastic (such as an acrylic or
polycarbonate) radiation conductive rod of non-critical
diameter, for example, of 1/4 inch and a length, which is
non-critical, but typically may be about 5 inches,
depending on the structure of the fixture lens. The
outer or free end of the receiver rod can be cut either
round, or square at its end, while the inner end of the
rod facing a sensor in the receiver housing may
preferably have a convex radius. The rod may be formed
with any desired axial elongation, for example, as a
straight rod which extends perpendicularly from the yoke
of the receiver housing, or with a bend or curve to meet
the needs of mounting the radiation receiver within a
fixture. Whatever shape is used, it is critical that the
free end of the radiation receiver is sufficiently long
that it is not shadowed by the fixture baffle or lens.
The receiver rod, which may be any desired
infrared (IR) transmitting plastic rod may be co-molded
with numerous differently shaped rods in a common mold
which are shipped with the light receiver housing and/or
system equipment so that the user can select the rod
shape best adapted to his fixture.
In an alternative embodiment and as a further
enhancement, a portion of the receiver may be covered
with an infrared shielding material or structure which
SPI~C\1491 15
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blocks lamp infrared and thus improves signal to noise
ratio, thus giving greater reception range. The shield
structure may be a parabolic curve to not only shield
infrared noise, but also focus infrared signals onto the
receiver rod.
Preferably, the radiation receiver rod or guide
can be connected to the receiver housing by a snap-fit
which permits the rod to rotate about its axis at its
connection to the receiver. Thus, the end connected to
the receiver housing is always fixed relative to the LED
or other radiation sensor within the housing, while still
permitting rotation of the rod to enable the adjustment
of the position of the free end of the rod at the outer
plane of the fixture lens. Note that other connections
can be used, such as compression fittings, a screw type
connection, a lock and key arrangement or a simple
bayonet-type connection.
The receiver housing of the present invention
must often be mounted remote from the location at which a
transmitter signal can be received. In such a case, an
elongated, flexible radiation conductor or light pipe of
up to 2 feet in length is employed, with one end fixed to
the receiver housing, and the free end secured, for
example, in the ceiling tile adjacent the fixture. In
prior devices employing infrared radiation as the
carrier, a conventional but expensive fiber optical cable
light pipe has been used, with one end located adjacent
the IR sensor in the receiver housing and the other "free
end" fixed to a connector to connect the free end through
a ceiling tile or the like to be exposed to the interior
of the room containing the lighting fixture. End ferrule
terminals are needed at the ends of such a light pipe.
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It is desirable to employ a less expensive infrared
conductor in place of the flexible light fiber conductor.
Visible light conductors are available which
are flexible thin cables with a bend radius as small as 1
inch. These are termed "end light fiber optics" and
consist of an elongated light transmitting silicon
monomer gel core which has a Teflon~ cladding layer and
an outer black plastic jacket. Such devices are used for
visible light conduction for spot, flood light and
underwater applications. The Teflon~ cladding acts as a
light shield and the black jacket is for U.V. protection
and prevents yellowing of the gel core. One such cable
is part number EL 100 made by Lumenyte International
Corporation of Costa Mesa, California having a length of
about 24 inches and a diameter of about 3/16 inch. Such
conductors are less expensive than conventional infrared
fiber optic conductors.
It has been believed that the light
transmitting core of end light fiber optics severely
attenuates infrared radiation, for example, radiation
with a wave length of about 880 nanometers. However, it
has been found, unexpectedly, and contrary to common
belief, that an end light fiber optics cable with a
visible light conducting gel core does not attenuate
infrared (at about 880 nanometers) sufficiently to
interfere with its use as an elongated (up to about 24
inch) infrared conductor for the present invention.
Thus, the invention can employ an inexpensive elongated
end light fiber optics conductor in place of an expensive
elongated infrared fiber optics conductor.
Note that the fixed end of the end light fiber
optics can be adapted to snap into or be fixed to the
radiation receiver housing in the same manner as the
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shorter rigid plastic rod previously described. Thus, no
change is required in the structure of the housing which
can universally receive radiation conductors of various
types. Where end light fiber optics cable is used, it is
not necessary to make the cable rotatable relative to the
housing in view of the inherent flexibility of the cable.
A special connector is provided to fix the free
end of the fiber optics cable to and through a ceiling
tile. In general the connector contains an elongated
hollow cylindrical bushing which has an elongated hollow
sleeve which fits snugly in an opening in the ceiling
tile. A flange is integral with one end of the
cylindrical body and seats on top of the surface of the
ceiling tile surrounding the opening in the tile. The
black jacket is stripped from the free end of the end
light fiber optics and is threaded through the
cylindrical bushing until its free end protrudes about 1
inch beneath the bottom of the ceiling tile. A trim
ring, which can receive a focusing lens is then pressed
onto the free end of the cable and into the bushing
sleeve to fix the cable and bushing to the tile.
A further feature of the novel bushing
structure consists of serrating the bottom end of the
bushing to form a circular saw edge. This serrated edge
can then be used to cut a circular opening through the
ceiling tile which will exactly match the outer diameter
of the bushing. The saw edge is covered by the trim ring
after installation.
It has been found that the radiation conductor
can pick up and respond to external radiation, for
example infrared from the lamps in the fixture. For this
reason, the "signal sensitivity" of the receiver is
reduced so that it is activated only by signals from the
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remote transmitter. This however slows down the response
time of the receiver to coded signals from the
transmitter.
In accordance with the improvement of this
invention, the receiver circuit is, in essence, switched
from an insensitive "wait" state (during which it does
not respond to extraneous infrared signals) to an
"active" and more sensitive state upon the reception of a
valid start signal sequence. Thus, when activated, the
system will respond to further signal data more easily.
More specifically, each signal train produced by the
infrared transmitter contains a start byte of 8 bits and
three data bytes or 24 bits. Each of the start bits is
sampled 4 times by the receiver, and all 4 samples must
confirm that the bit is high (termed 4 of 4 voting) to
comprise a valid high bit. If all eight start bits are
high, i.e., 32 consecutive high samples, the
microcontroller will identify a valid input signal and
act on the data signal. However, the next 24 data bits
and all succeeding signals are subject to only 3 of 4
voting to be considered valid, thus allowing the control
system to operate more smoothly. That is, while all bits
are sampled 4 times, only 3 need to be high to consider
the bit to be high. The standard remains at 3 of 4
voting if and only if a repeatable command has been
decoded (raise light level, lower light level or program
mode). If the command is not repeatable (go to 100~
light or go to another preset light level), the voting
standards are changed back to 4 of 4. Repeatable
commands such as raise or lower only cause a small change
to the light level. In order to go from a low light
level to a high light level, for example, the unit must
receive many commands. By relaxing the voting standard,
SPEC\1491 15
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the change is perceived as smoother. This process
continues until 1.5 seconds (or any other selected time)
has elapsed without a command, and the system then
reverts to 4 of 4 voting, termed herein, the
"insensitive" state. Note that while the terms used
above are "4 of 4 voting" and "3 of 4 voting"
respectively, they could more broadly be understood to
refer to 100% voting and 75% voting respectively.
As another feature of the present improvement,
the receiver housing contains a positive switch for
example, relay contacts or a triac or the like in series
with the ballast power circuit for switching off its
respective ballast. This positive switch is mounted
within the receiver housing.
As a still further feature of this invention,
the novel receiver structure and circuit is incorporated
into the ballast housing, and the radiation signal is
brought through an infrared transparent portion,
typically, an opening in the ballast housing and into the
radiation receiving circuitry. The combination of these
two parts within a common housing produces cost and space
savings from the common use of circuits and supports and
eliminates the external wiring between the two circuits.
Thus, a common housing permits the use, for example, of a
common power supply, common output drivers and a common
printed circuit board.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a block diagram of the lighting
fixture adapted with a radiation receiver/ballast control
circuit with remote radiation transmitters and which can
employ the present invention.
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Figure 2 is an elevational view of the
receiver/ballast control circuit housing which can employ
the present invention.
Figure 3 is, in part, a cross-section of Figure
2 taken along the section line 3-3 in Figure 2 and also
shows the plastic yoke, fixture rear surface and wire-way
cover, and a hook and loop type fastener in a partly
exploded view.
Figure 4 is a bottom view of the
receiver/ballast control circuit housing of Figures 2 and
3.
Figure 5 shows 4 differently shaped plastic
radiation conductors or lenses fastened to a common mold
sprue.
Figure 5a shows the lens structure on the
housing of Figure 3 as disclosed in earlier application
Serial No. 08/407,696.
Figure 6 shows one of the conductors of Figure
5 and shows the detail of its mounting flange and snaps.
Figure 7 is a top view of Figure 6.
Figure 8 is a detailed view of the mounting
flange and snaps of Figures 6 and 7.
Figure 9 is a partial cross-sectional view
showing the receiver/ballast control circuit of Figure 3
with the lens of Figures 6 and 7 located within the wire-
way of the fixture, and connected internally of the
fixture to the dimming ballast leads.
Figure 9a is an enlarged detail drawing of the
connector structure of Figure 9.
Figure 10 is a view of the bottom or light
output side of a fluorescent light fixture with a
prismatic lens which contains the novel infrared receiver
of the invention.
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Figure 11 is a cross-section of Figure 10,
taken across the section line 11-11 in Figure 10.
Figure 12a shows a novel radiation
receiver/ballast control with an infrared shield covering
the radiation conductor except for its very tip.
Figure 12b shows a radiation receiver/ballast
control with an infrared shield and focusing cone.
Figure 13 is a cross-section of a fixture like
that of Figure 11 but with a parabolic louver instead of
a prismatic lens and shows the manner in which the
radiation receiver protrudes through the bottom plane of
the lens.
Figure 14 is a perspective view of an
alternative type of fixture with a parabolic louver
showing an alternative placement of the radiation
receiver/ballast control circuit and its infrared
conductor rod.
Figure 15 is a schematic cross-section of a
compact fluorescent down-light fixture equipped with the
receiver/ballast control circuit and the radiation
receiver of the invention.
Figure 16 is a schematic cross-section like
that of Figure 15 of a modified compact down-light
fixture containing the receiver/ballast control circuit
and the novel end light fiber optics of the invention.
Figure 16a is a cross-sectional view of a known
end light fiber optics for conduction of visible light.
Figure 17 is an exploded cross-sectional view
of the mounting bushing which mounts the end light fiber
optics of Figure 16 to the ceiling tile.
Figure 18 is a cross-section of Figure 17 taken
across section lines 18-18 in Figure 17.
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- 18 -
Figure 19 schematically shows the application
of the novel invention to an incandescent canopy fixture.
Figure 20 is a flow diagram of the program
installed in the microcontroller of Figure 1 to prevent
operation of the system by stray infrared radiation.
Figure 21 is a block diagram showing the
receiver circuit and ballast circuit integrated into a
common housing.
Figure 22 shows a semi-rigid lightpipe
structure.
Figure 23 shows another semi-rigid lightpipe.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring first to Figure 1, there is shown a
block diagram of the system which incorporates the
invention in which a single radiation receiver/ballast
control circuit 20 contains a circuit consisting of a
power supply 21, an infrared signal receiver 22, an
EEPROM circuit 23, a microcontroller 24 and a dimmer
circuit 25 which includes an appropriate semiconductor
power switching device. An on/off power switching device
26 such as a triac or relay contacts or the like can be
included in series with the ballast power wire and is
operable from an output from microcontroller 24.
While receiver 22 could respond to any desired
narrow band radiation, it is preferably a receiver of
radiation in the infrared band.
Radiation receiver/ballast control circuit 20
is mounted within a lighting fixture 30 as will be later
described in more detail. Fixture 30 also contains a
dimming ballast 31 of known variety which can energize
one or more gas discharge lamps, such as 32-watt
fluorescent lamps, in a controlled manner. Ballast 31
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may be a dimming ballast known as the "Hi-Lume" ballast
or the "ECO-10" ballast, each sold by Lutron Electronics
Co., Inc., the assignee of the present invention.
Ballast 31 typically has three input leads
taken from radiation receiver/ballast control circuit 20,
including lead SH (switched hot), lead DH (dim hot) and N
(neutral). The ballast can, however, have control
arrangements other than those using three input leads.
For example, a 0-10 volt control can be used, with its
typical four-lead wire system (hot, neutral, purple and
gray), as used for low voltage controlled ballasts.
Input leads SH (switched hot) and N (neutral) in Figure 1
are connected to receiver/ballast control circuit 20.
Significantly, since receiver/ballast control circuit 20
and ballast 31 are both within fixture 30, all wiring
interconnections between the two are also within the
fixture.
In order to control the light level of the
fixture of Figure 1, an infrared transmitter of known
variety is employed. Thus, two kinds of transmitters are
shown in Figure 1. The first is transmitter 40 which is
a known type of raise/lower transmitter. Transmitter 40
is a small hand-held unit which has an "up" control
button 41 and a down control button 42. Pressing either
of these buttons 41 or 42 will cause the generation of a
narrowly focused coded beam of infrared radiation 43
(with an 8 beam angle) which can illuminate the IR
sensor in receiver 22 to cause the lamps controlled by
ballast to increase or decrease, respectively, their
output light.
As will be later seen, a plurality of spaced
fixtures 30 in a single room can be individually
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controlled by a single transmitter 40 from almost any
location in most rooms.
A more elaborate transmitter 50 may be used in
place of transmitter 40. Thus, transmitter 50 is of the
type sold by Lutron for the remote control of wall
mounted dimmer controls sold under the trademark, Grafik
Eye. The transmitter 50 has an up/down control 51 and a
plurality of push buttons 52 which correspond to, and
place the ballast 31 in one of a plurality of preset
dimmer conditions. Its structure and operation is
described in U.S. Patent 5,191,265.
As will later be described, either of the
transmitters 40 or 50 may also be used to calibrate the
dim settings of the lamps being controlled in the manner
described in U.S. Patent 5,191,265. When using the
transmitter 50, low end calibration, high end
calibration, and other parameter calibrations can be
accomplished by pressing combinations of preset buttons
52 to send out appropriately coded signals.
The structure of radiation receiver/ballast
control circuit 20 of Figure 1 is shown in Figures 2, 3
and 4. Referring to these figures, the radiation
receiver/ballast control circuit 20 is housed in a
conventional plastic back box 60 which has projecting
mounting ears 61 and 62. A circuit board 63 is mounted
to yoke plate 70 on conventional snap-in posts 64 and 65
(Figure 3). Circuit board 63 carries infrared sensor 22,
or an equivalent radiation sensor for the particular
carrier used to carry the remote signal and also carries
integrated circuits including the power supply 21,
microcontroller 24 and EEPROM 23 and, in some cases, the
power semiconductor 25 of Figure 1. Leads SH, DH and N
extend through an opening 66 in the housing 60. A
SPEC\1491 15
" 2l72l~a
further positive on/off switching device can also be
added to act as a positive on/off sensor switching device
to switch the ballast power.
The side of housing 60 is ordinarily closed by
a metal yoke. When using the present invention, the yoke
plate 70 is formed of plastic and has a hole 71 cut in it
which is transparent to the infrared or other signal
carrying radiation which is used. Thus, as shown in
Figure 4, the sensor 22 can be illuminated through plate
70.
In order to mount the housing 60 within a
lighting fixture, a novel hook and loop tape (sold under
the trademark Velcro) mounting system may be used. Thus,
Velcro tape, supplied in reel form, has two cooperating
tapes releasably fastened together with a pressure-
sensitive adhesive on their outer surfaces. The adhesive
surfaces are covered by release strips. Two lengths 75
of such tape are cut to fit over portions of yoke 70 as
shown best in Figure 4. The release strips are removed
from upper Velcro strips 76 and the Velcro strips are
adhered to the bottom of yoke 70. When the housing 60 is
to be mounted, the release strip on the bottoms of tape
strips 77 are removed (Figure 3). The housing 60 is then
positioned so that the light sensor 22 is disposed above
the radiation receiving openings 80 and 71 (Figure 3) in
wire-way cover 79 or on some other portion of the
fixture. The lower strip is then pressed into contact
with the rear interior surface of the lighting fixture
wire-way cover 79 (Figure 3). Other fasteners can be
used such as bolts, rivets, magnets, double-sided tape
and the like to fix housing 20 to the fixture 30.
In the structure disclosed in above-noted
patent application Serial No. , a snap-in
SPEC\1491 15
217219Q
-
infrared lens 81 was snapped into opening 71 as shown in
Figure 5a. The lens 81 is designed to have any desired
angle of acceptance of incident radiation, and hence
different lenses may be used to suit the requirements of
a particular application. For example, the lens 81 may
be a fresnel lens 82 so that infrared radiation coming
toward lens 81 from even very shallow angles to the
ceiling surface will be refracted along its axis and
toward sensor 22, through hole 71 in yoke 70.
The above noted application Serial No.
also discloses that a light (infrared) conducting fiber
can convey sensed radiation to the sensor 22 if the
sensor 22 is removed from the receiver.
In accordance with one aspect of the present
invention, the fresnel lens 82 is replaced by an
elongated light conductor 83 (Figures 5 to 9 and 9a).
Lens 83, in a preferred embodiment of the invention, is a
molded plastic lens which may be co-molded with a
plurality of other lenses of diverse shape, such as
lenses 84, 85 and 86 in Figure 5 which share a common
sprue 87 from which they can be easily removed. The lens
83 is preferably made from an acrylic plastic. Other
plastics can be used, for example, polycarbonates, which
conduct the sensed radiation used in the system from an
exterior end to an interior end near a radiation sensor.
The assemblage of 4 lenses 83 to 87 can be shipped to all
customers, who will select the shape best adapted to
their installation, as will be later discussed. Note
that the lens 83 has a radiused end 83a and a square end
83b. Unexpectedly, best performance has been observed
when the radiused end 83a faces the radiation sensor 22
(see Figure 9) and the square end 83b is the end facing
outwardly of the fixture as will be described.
SPEC\1491 15
217219~
Figure 9 shows receiver housing 60 fixed in
position between a fixture rear surface 78 and wire-way
cover 79 as previously described. Figure 9 also shows
the dimming ballast 90 which is also fixed to fixture
surface 78 in any suitable manner. Ballast 90, which may
replace a non-dimming ballast in a retrofit installation,
has three input leads SH, DH and N which are conveniently
connected to corresponding leads from radiation
receiver/ballast control circuit 20 within the fixture
interior. Output ballast leads 91 are connected to the
lamps.
Ballast 90 can be any desired dimming ballast,
for example, the Lutron~ Hi-Lume~ ballast.
During the retrofitting operation, the
installer need only drill the small hole 80 in the wire-
way cover 79. The ballast 90 and radiation
receiver/ballast control circuit 20 are then easily
installed and wired together and the wire-way cover is
reinstalled with lens 83 aligned to the position of hole
80 in wire-way cover 79. Thus, retrofitting is easily
done in a short time.
In accordance with the preferred embodiment of
this invention, the elongated lens, for example lens 83
of Figures 5, 6, 7 and 8, is arranged to snap into the
opening 71. One alternative is to have it rotatable into
the opening 71 to enable lateral movement of end 83b for
reasons to be later described. The snap-in structure is
enabled in any desired manner. For example, lens 83 may
be molded with a flange 83c (Figures 6 to 8 and 9a) and
with spaced projections or snaps 83d, 83e and 83f
(Figures 8 and 9a). The projections can be forced
through opening 71 to snap over the top of plate 70 to
hold flange 83c against the bottom surface of plate 70.
SPeC\1491 15
_ 21721~3~
- 24 -
However, the fit is sufficiently loose to allow the
rotation of lens 83 within opening 81.
In one embodiment of the invention, the molded
lens 83 had a length from flange 83c to end 83b of about
4 inches, with the bottom section from flange 83c to end
83a being about 0.45 inch. The diameter of the rod 83
was about 0.248 inch and the diameter of flange 83c was
about 0.348 inch and its axial length was about 0.050
inch. The space between flange 83c and the plane of the
facing surfaces of projections 83d, 83e and 83f was about
0.060 inch. The projections are tapered barbs having a
length of about 0.030 inch and a height of 0.015 inch.
The end 83a had a radius of 0.125 inch.
It should be noted that other connection
structures could be employed. For example, a friction
fit could be used, and a permanent bolted arrangement
could be employed. Preferably, the same fit is used for
any of the molded lenses of Figure 5 or of a fiber optic
cable if one is used so that the connection of housing 60
to external optics is universal.
Figures 10 and 11 show a conventional
fluorescent light fixture 100 with a prismatic lens cover
101. A typical fixture of this type will be two feet
wide and four feet long and will contain four 32-watt
fluorescent bulbs 102, 103, 104 and 105. All wiring and
the ballast 90 for the lamps is contained behind wire-way
cover 79 which may be bolted or otherwise fastened to the
fixture rear 78. Ballast 90 and radiation
receiver/ballast control circuit 20 are contained within
the fixture so that wiring connecting the two is not
exterior of the fixture. Moreover, in accordance with
the invention, the lens 84 projects out of the plane of
the bottom surface of the lens cover 101 and through an
SPEC\1491 15
217219~
- 25 -
opening in the lens cover, or in its support. Note that
in Figure 11 the rod 84 is straight. However, if the
housing 60 were mounted on the side of cover 79, the lens
83 would be used, with its elongated portion projecting
vertically. By having the end of the lens project beyond
the surface of lens cover 101, any shadowing effect of
the lens to line of sight radiation, and unanticipated
reflection is eliminated. Thus, better operation is
experienced by having the end of the rod 84 either flush
with, or protrudes beyond the bottom plane of lens 101.
Best results have been found with the lens protruding
about ~", but it can protrude by other distances.
In the case of prismatic lenses, it has also
been found that improved operation is also obtained if
the end of radiation conducting rod lens 84 is located
close to the top surface of the lens cover 101 to avoid
the need for cutting an opening in the lens cover 101.
Further improved sensitivity may be obtained if rod 84 is
shielded, as by shield 504 of Figure 12a. Shield 504 has
a focusing end 506 which can be conical or parabolic to
focus desired IR signals onto the end of rod 84.
The invention can be applied to many other
types of fixtures. For example, Figure 13 shows a
fluorescent light fixture with a louver or parabolic lens
cover 110 in place of the prismatic lens 101 of Figure
11. The fixture of Figure 13 has two wire-way covers 111
and 112 for three lamps 113, 114 and 115. The ballast
(not shown) and the radiation receivertballast control
circuit 20 are mounted within cover 111. The radiation
receiver/ballast control circuit 20 is preferably mounted
on one of the sloped sides of cover 111. Its lens 83, in
accordance with the invention, projects to or beyond the
plane of the bottom of lens cover 110 to be free of any
SPl~C\1491 15
21~2~9~
.
- 26 -
shadowing or reflection of the line of sight radiation
from the remote transmitter of Figure 1 at lens 83. Note
that lens 83 can be rotated to any position necessary.
Best results have been obtained with the lens protruding
about ~", but it can protrude any amount.
Figure 12a shows a further improvement wherein
lens 83 is covered with an infrared shield 502 except for
the very end which is exposed. This blocks unwanted
direct IR radiation from the lamps from reaching the IR
sensor, but allows desired IR signals to be received at
the exposed end and conducted along rod 83 to the IR
sensor. This IR shield is shown with the bent rod 83,
but can be used with a rod of any shape.
Figure 14 shows a fixture 116 with a pivotally
mounted louvered lens cover 117, shown in the open
position. A ballast 90 is fixed to the interior of the
fixture. A housing 60 is then fixed to the bottom of end
channel 118, and a straight plastic lens 84 extends
outwardly and is of sufficient length to extend to or
beyond the bottom plane 117a of the lens cover 117 when
the cover is closed. A cut-out 117b is formed in the
lens cover flange 117c to permit opening and closing of
the lens cover 117 and permits the lens 84 to protrude
through the cover 117 when closed and to provide
sufficient clearance to open the cover 117 without
disconnecting lens 84.
Figure 15 shows the manner in which the
invention may be applied to a compact fluorescent down-
light fixture housing 120. Thus, a compact fluorescent
lamp 121 is contained within reflector 122. A dimming
ballast 123 is fixed to the exterior of housing 120 and
its input wires 124 (SH, DH and N leads) are connected to
related output wires 125 of radiation receiver/ballast
SPEC\1491 15
217219~
- 27 -
control circuit 20. Radiation receiver/ballast control
circuit 20 is mounted internally of fixture housing 120
as desired and lens 86 protrudes through an opening in
housing 120 to be exposed to infrared signal
illumination. The wiring connections between radiation
receiver/ballast control circuit 20 and ballast 123 are
made within the interior of housing 120. The output
wiring 126 from ballast 123 to lamps 121 is also
contained within the interior of housing 120. All input
power lines (Switched Hot and Neutral) 127 come into
housing 120 through wiring conduit 128. Thus, as in the
prior embodiments, an unobtrusive infrared sensor is
fixed to or retrofitted into an existing fixture 120 and
all wiring connections are kept within the interior of
housing 120.
Figure 16 shows another type of fixture for
compact fluorescent lamp 121 and a novel means for
bringing the infrared signal to the sensor in housing 60.
Thus, the housing 130 is a cone which is suitably mounted
flush with the ceiling tiles of a ceiling 131. A wiring
box 132 is fixed to cone 130 and a dimming ballast 133
and radiation receiver/ballast control circuit 20 are
mounted on opposite sides of box 132 and are
interconnected within the box 132. Input power is
brought into the fixture via metal conduit 137 and the
output lines to lamp 121 are contained within conduit
134. Since this structure physically removes radiation
receiver/ballast control circuit 20 from the area of
ceiling 131, a "light pipe" 135 which terminates at lens
81 is snap-mounted into the ceiling tile 131.
The light pipe previously used has been a
flexible fiber optics line with connection ferules at
either end. Such structures are quite expensive. In
SPEC\1491 15
21721g~
- 28 -
accordance with an important feature of the invention, a
much less expensive flexible conductor is used for light
pipe 135 which was previously thought useful only for
visible light rather than infrared at 880 nanometers.
Thus, in accordance with the preferred embodiment of the
invention, and as shown in Figure 16a, end light fiber
optics is employed for light pipe 135 which consists of a
silicon monomer gel core 135a wrapped with a Teflon~
sheath 135b and a black plastic jacket 135c. The Teflon~
sheath 135b is employed to ensure internal reflection as
radiation traverses the length of the core 135a and the
black jacket 135c is employed to shield the core 135a
from ultraviolet light which tends to cause the core 135a
to yellow. The gel core which has a diameter, for
example, of 1/8 inch was believed to attenuate infrared
severely and could not be used for infrared transmission.
We have found that lengths up to 24 inches of such light
pipes transmit ample infrared at 880 nanometers to be
perfectly adequate for use in most systems.
In the preferred embodiment of Figure 16, the
line 135 is an end light fiber optics, for example, part
No. EL 100 sold by Lumenyte International Corporation.
It has a length less than about 24 inches and a minimum
bend radius of about 1 inch. The material is much less
expensive than convention infrared fiber optics with
connection ferrules.
Another significant feature of the invention
involves the connector structure 200 (Figures 16, 17 and
18) employed for connecting light pipe 135 to the ceiling
tile 131. The novel connector consists of a plastic
bushing 201 having a flange end 202 and a thin integral
rigid extending hollow cylinder 203. The cylinder 203
may have a serrated or saw-tooth end 204 so that the
SPEC\1491 15
21721~
- 29 -
bushing 201 can be used by hand oscillation about its
axis, to cut a hole in the tile 131 which will snugly
receive the cylinder 203 used to cut the hole.
Flange 202 has a central opening which snugly
receives the outer diameter of a short length of light
pipe 135. The black jacket 135c (Figure 16a) is removed
from the light pipe for an end portion of its length that
fits through bushing 201.
An external coupler 210 or trim ring, which is
a molded plastic part, has a finishing flange 211,
adapted to cover the end of cylinder 203 and the opening
in tile 131 and press against the bottom of ceiling tile
131. Ring 210 has a hollow central extension 232. The
external diameter of extension 232 snugly into the
interior of sleeve 203 while the end of light pipe 135
fits through the center of and beyond the bottom of ring
210. A plastic red fresnel lens 235 (which is like lens
81 of Figure 5a) fits snugly into the bottom of fitting
210 to cover the free input end of light pipe 135. The
fitting 210 will fit against the bottom surface of tile
131 when assembled, as shown in Figure 16.
Figure 22 shows a novel semi-rigid optical
structure. This combines features of the rigid lenses
83-86 with those of the flexible light pipe 135. The
rigid lenses do not require the free end to be secured,
but the position of the free end is predetermined by the
shape of the lens. on the other hand, the free end of
the flexible light pipe can be placed in any location,
but must be secured in order to maintain a given
position.
The novel semi-rigid optical structure
illustrated in Fig. 22 is constructed so that it can be
bent by hand to place the free end at any desired
SPEC\149115
21721!3(~
- 30 -
location for best reception of an IR signal and will
retain that position without having to be secured.
The novel light pipe 510 is similar to light
pipe 135 with the addition of a semi-flexible wire 512
which is positioned under shielding 514. Wire 512 is
semi-flexible and the entire assembly can be bent to any
desired shape by hand. However, the assembly is still
rigid enough that, when the bending force is removed, the
assembly is self-supporting and retains the desired shape
in the manner of a pipe cleaner.
Figure 23 shows another novel semi-rigid
optical structure. This structure also has the
flexibility of the flexible light pipe and the ability to
maintain a given position like the rigid lenses.
The novel semi-rigid optical structure
illustrated in Figure 23 is of similar material to the
rigid lens 83 (e.g., an acrylic plastic) but the
polymerization process has been shortened to allow the
lens to be flexible and also maintain a given shape
without the need for the semi-flexible wire 512.
In a preferred embodiment, a copper wire 512 of
#16 AWG has been found to provide adequate stiffening but
still allows the light pipe 510 to be semi-flexible and
bendable by hand to a given desired permanent position.
The copper wire is shown in parallel with the fiber, but
it could be wrapped around fiber or made into a
continuous shield. Materials wlth similar properties to
copper can be used.
The present invention can also be applied to
incandescent lamp ceiling fixtures, as shown in Figure
19. Thus, in Figure 19, an incandescent canopy fixture
140 includes a wiring box 141 fixed to ceiling 142. A
support plate 143 extends across box 141 and receives a
SPEC~1491 15
217219~
- 31 -
hollow threaded screw 144 which supports a lamp holder
145 from chain 146. In accordance with the invention, a
radiation receiver/dimmer housing 20 having a lens 83
protruding external of housing 140 is mounted within the
housing 140. Power wiring from box 141 is connected to
radiation receiver/dimmer 20 which contains a power
semiconductor dimmer (25 in Figure 1) which is controlled
by infrared signals received through lens 83. Output
wiring from radiation receiver/dimmer 20, including the
dim hot and neutral wires, extends through the center of
support screw 144 to the incandescent lamp or lamps in
holder 145.
It will be apparent that incandescent lamp
fixtures distributed over the surface of a ceiling can
each be adapted as shown and described in Figure 19 to be
selectively dimmed to suit individual users in different
locations in the room. Moreover, such lamps can be
mounted on centers greater than about two feet and still
be discriminated from one another by an infrared
transmitter having a beam dispersion of about 8. It
will also be apparent that the novel receiver of the
invention can also be used on wall sconces and lamp cords
and the like, as well as on recessed incandescent
downlights similar in design to those of Figures 15 and
16 but designed for use with incandescent rather than
fluorescent lamps.
Further, the invention can be applied to track
lighting fixtures where the receiver/dimmer is built into
an adaptor which mounts to the track and the fixture to
be controlled is mounted to the adaptor.
A single receiver can control a plurality of
ballasts which are in spaced fixtures. Fixtures equipped
with the receiver of the invention can be used with added
SPI~C\1491 15
21721~J~
- 32 -
inputs, such as photocell detectors for adjusting lamp
intensity in accordance with ambient light. Furthermore,
the novel receiver can also be used with external dimming
controls in which dimming of lamps can be accomplished
under the control of an infrared transmitter, an
occupancy detector, or a manual control or timer or the
like as is described in copending application Serial No.
As a further feature of the present invention,
a novel control is employed for the microcontroller 24
which increases the sensitivity of the system to input
infrared data signals. More specifically, since there is
extraneous infrared in the ambient coming, for example,
from the light being controlled and other sources, means
are necessary to ensure that a valid signal was received
from the remote transmitter before a change was executed.
In the prior (and present) system, the infrared signal
consists of a continuing sequence of 8 start bits,
followed by 24 data bits. To ensure the presence of
valid signals, each of the bits is sampled four times to
see if they are high. All four samples must be high for
the bit to be considered high. This system is termed "4
of 4 voting". If all eight of the start bits are high
(i.e., 32 consecutive high samples), the system
recognizes a valid start bit. The voting is then relaxed
to a more sensitive "3 of 4 voting" standard. The system
remains at 3 of 4 voting if and only if a repeatable
command has been decoded (raise or lower light level or
program mode). If the command is not repeatable, the
voting returns to 4 of 4. The system then acts with the
3 of 4 voting standard until no new data is received or
until 1.5 seconds have elapsed since the last command was
received. Thus, the system will revert to an
"insensitive" state when no valid signal is present (and
SPEC\1491 15
~17219~
- 33 -
thus is less responsive to spurious infrared signals) but
will be more sensitive in the presence of a valid signal.
Figure 20 is a flow chart of the novel system
described above. In Figure 20, at the start, the
processor operates with a 4 of 4 voting standard. Data
enters the sample infrared port 300, and the 4 of 4
determination is made with respect to the first 8 start
bits of whether all 32 samples (4 for each bit) have been
high (block 301). If so, a determination is made that a
valid start byte has been detected (block 302). The
microcontroller then relaxes the voting standard to 3 of
4 voting (block 303) and the next 24 bits (data bits) are
sampled with the relaxed standard (block 304). The data
received is decoded and acted upon (block 305).
A determination is next made of whether the
data is for a repeatable command (block 306). If it is,
the system continues to sample with 3 of 4 voting,
looking for the next start byte (block 307). If not, the
system reverts to the 4 of 4 voting standard.
Once 1.5 seconds (or any other desired time
lapse) has gone by without a command, the system will
revert to the "insensitive" 4 of 4 voting standard (block
308). However, if a new start byte is detected, the
system remains in the 3 of 4 voting standard (block 309).
Describing the above operation further, it will
be noted that the system is constantly sampling its IR
port. The sampling occurs at a rate that will yield 4
samples per transmitted bit. When the system is in its
insensitive state, four adjacent samples must be high if
the microcontroller is going to consider a bit high.
The system stays in its insensitive state until
it has received 32 consecutive high samples (8 high
bits). After the 32nd high sample, the system has
SPI~C\1491 15
2172190
- 34 -
interpreted a start bit, and relaxes the voting standards
to 3 of 4 (3 out of the last 4 or 4 out of the last 4
samples must be high to interpret a high bit).
The voting standards remain at 3 of 4 until the
24 bits of data information are received and decoded.
The standards remain at 3 of 4 if and only if a
repeatable command has been decoded (raise or lower light
level or program mode). If the command is not repeatable
(go to 100% light or go to lowest light level), then the
voting standards are changed back to 4 of 4.
When the system receives a raise lights
command, only a small change is made to the light level.
The system must receive many raise commands to get the
light to go from low to full light output. Relaxing the
voting standards after the first raise command has been
issued makes it easier for the system to receive
additional raise or lower commands.
After 1.5 seconds have elapsed after the last
repeatable command, the voting standards are put back to
4 of 4 voting to prevent false start byte triggers.
The reason for moving to 3 of 4 voting for
repeatable commands is to make dimming appear smooth.
There would otherwise be interference when changing light
levels and the system would have gaps in the repeatable
command stream.
As another important feature of the invention,
and as shown in Figure 21, the ballast 31 and the
radiation receiver ballast control circuit may be
combined in a common single housing and share a common
power supply and other commonalities. The novel
combination is shown in Figure 21 in block diagram and
schematic form. More specifically, in Figure 21, all
components are mounted within a common housing 400, shown
SPel~\1491 15
- 217219~
- 35 -
in dotted line, and having approximately the same volume
as the housing for ballast 31 of Figure 1. The wall of
housing 400 is penetrated by a light pipe 135 of
structure similar to that of Figure 16, although any
desired light receiver including those of the other
preceding figures and of application Serial No.
could be used. The light pipe 135, however, is
preferred because of the usual remote location of the
ballast in the fixture.
The components within the housing 400 will
include an RFl filter 401 connected to the a-c mains and
a rectifier 402. The d-c output of rectifier 402 is
connected through inductor 403 and diode 404 to the
inverter comprising MOSFETs 405 and 406. The node
between MOSFETs 405 and 406 is connected to ballast
transformer 407 which is coupled to the fluorescent lamp
408 or plural lamps, as desired. Capacitor 411 is in
series with inductor 407 and resonates therewith at the
desired frequency at which lamp 408 is driven. A further
MOSFET 409 and capacitor 410 are provided for the
conventional boost converter shown. A ballast control
IC 420, which is a MOSFET driver, is provided to control
the MOSFETs 409, 405 and 406 in an appropriate and known
manner. The driver 420 is controlled, in turn, by
microcontroller 24 (Figure 1).
All of the structure given above, except for
the microcontroller 24, are parts of the conventional
ballast 31 of Figure 1. Also included within the housing
of ballast 31 is a power supply for driving the control
ICs 420. A power supply for ICs 420 is shown in Figure
21 as power supply 421. Power supply 421 derives its
power from the positive output terminal of power supply
402, shown as the output line "A" which is connected to
SPÆC\1491 15
`- 2172190
- 36 -
the input of chip power supply 421. The receiver
structure in Figure 21 also has the IR receiver circuit
22, microcontroller 24 and E2 23 within the housing 400.
In accordance with the invention, the placement
of the components of receiver 20 of Figure 1 results in
economies of commonality of components and a reduction of
space. Thus, the same power supply 421 for ballast
control 420 can also serve the purpose of power supply 21
of Figure 1. Further, a single circuit board could be
used for all circuits. Finally, the separate housing 60
of Figure 2, 3 and 4 is eliminated.
In a further improvement, microcontroller 24
and ballast control IC 420 can be combined together to
further reduce cost.
Although the present invention has been
described in relation to particular embodiments thereof,
many other variations and modifications and other uses
will become apparent to those skilled in the art. It is
preferred, therefore, that the present invention be
limited not by the specific disclosure herein, but only
by the appended claims.
SPEC\1491 15
