Note: Descriptions are shown in the official language in which they were submitted.
CA 02488674 2004-11-30
MULTIPLE DIMMER LIGHTING SYSTEM
SPECIFICATION
FIELD OF THE INVENTION
This invention relates to outdoor lighting, where variation in placement and
brightness of
individual lights may provide striking contrasts of illumination of plants or
buildings
within a garden or other area.
SUMMARY OF THE INVENTION
A system of lighting in which a multitude of secondary line extra-low voltage
lights each
have an individual dimmer control enables setting of individual brightness for
each light
in the plurality. Each individual dimmer control can be pre-set during
installation or
adjusted afterward. The entire system can be switched on or off with a manual
switch,
timer switch, or photocell switch on the primary line voltage side of an
approved
transformer for the system. "Line voltage" is defined as voltage in the range
of 30 -750
Volts. Household electrical voltage of approximately 110 Volts is an example
of line
voltage. "Extra-low voltage" is defined as voltage of less than 30 Volts.
Garden lights
CA 02488674 2004-11-30
and study lamps are often run at 12 or 24 volts and are an example of extra-
low voltage
lines. The secondary line extra-low voltage lights with their respective
individual
dimmer controls are powered from the extra-low voltage secondary side of the
transformer, preferably in the range of 10 to 24 Volts.
The multiple dimmer lighting system adjusts the brightness and power drawn by
individual lamps via a configuration of secondary extra-low voltage lines. The
extra-low
voltage lamps thus have their light output adjusted individually. A printed
circuit board
which contains the control circuitry is mounted inside each lamp unit. After
adjusting
each lamp for brightness, the entire system can be turned on and off with a
single switch.
The system allows the use of extra-low voltage lamp units and extra-low
voltage lines to
connect the lamps in a configuration of AC or DC circuits preferably in the
range of 10 -
24 volts, with light bulbs or like lighting units preferably being rated in
the range of 12 to
40 Watts.
Such extra-low voltage lines are suitable for installation by home owners and
amateur
electricians as garden lighting. The lines can be buried without special
conduits or
building permits in many areas, preserving safety for pets, children and
others who might
later dig in the area in which the system is installed.
The dimmer control circuit compensates for voltage drop input and gives
substantially
the pre-selected light output, despite variations in secondary side output
from the
transformer or voltage drop due to secondary line length for various
individual secondary
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power supply lines in the configuration. The individual lamp brightness is
controlled by a
switching dimmer circuit which varies the duty cycle of the power. This
affects the lamp
on time and hence varies the light output. To minimize lamp brightness changes
with
minor voltage variations, the supply voltage is sensed through divider
resisters with
feedback to an adjustment subcircuit. The voltage at the junction of the two
resisters is
fed to the integrated circuit to vary the duty cycle inversely to the supply
voltage, thereby
reducing the duty cycle as the voltage increases to maintain the lamp
brightness about a
constant level.
In a preferred embodiment, each unit lamp is contained in a housing that is
substantially
spherical and watertight sealed, suitable for embedding in a garden or beneath
a shrub or
tree, with its light aperture uncovered and oriented in a selected direction.
When buried
the housing is secure and stable in its orientation and protected from
collision or
vandalism.
The system switch can be an ordinary electrical wall-mounted switch inside or
outside a
house or building adjacent to or integral with an approved transformer. The
system
switch is on the primary voltage side of the transformer with the
configuration of
individual lamps connected to the secondary side of the transformer.
Optionally, the
system switch can be part of a remote control module implementing one of two
methods.
Radio, comprising a portable electronic radio frequency electronic remote
control
transmitter that transmits signals to control units in the housing of
individual lights could
be used, but it would be expensive. Alternatively and less costly, data can be
sent down
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the power cables, using a remote control unit that would talk to a master
receiver which
would then send the signal down the power lines. Whether radio or data down
the power
cables is used, each lamp has its own ID and so although the signal would be
received by
all the lamp units, only the one with the correct ID would respond to the
command.
As a further option, the system can be programmable such that the extra-low
voltage
lamp units can be turned on or off in accordance with a predetermined order,
to perform a
light show. Several modes can be stored, for example, a bright mode for a
party, a
dimmer mode when users of the ground are unlikely, and an emergency or alarm
mode.
The individual lights are preferably supplied with soft-start electronics so
that the
individual lamps' brightness is increased gradually after turning on the
system until each
individual lamp reaches its pre-set brightness level set by its dimmer
circuit. The soft-
start is part of the control integrated circuit and minimizes current surges
and so helps
extend the life of the individual lamps. The integrated circuit used is for
power supply
circuits where current surges can be damaging. So$ start occurs very quickly
in the
matter of a fraction of a second and may be barely noticed by an observer when
the
lamps are turned on. A longer, more noticeable soft start for aesthetic
purposes could
optionally be programmed into the system and could be done irrespective of
remote control.
The invention thus comprises a system of lighting in which a primary line
voltage switch
turns on or off a plurality of secondary extra-low voltage lines and lights
each having
individual dimmer controls that enable setting of different individual
brightness levels.
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The dimmer controls each have a voltage variation compensating circuit that
maintains a
pre-selected brightness level for its light despite supply line voltage
variations to the
transformer or extra-low voltage variations in the transformer's output.
An excellent embodiment would be to have such a system of multiple
individually
dimmed lights, in which:
a) a plurality of individual dimmer controls can be accessed after
installation for
adjustment of pre-set dimming;
b) a soft start module controls the multitude of lights upon turning on the
system such
that the lights gradually brighten to a pre-set level;
c) a plurality of lights are each encased in a substantially spherical housing
suited for
tilting in a substantially spherical mounting place at various selected
orientations;
d) a plurality of lights are each encased in a weather-proof housing suited
for partial
burial in a garden;
e) extra-low voltage insulated electrical supply lines are used to connect a
plurality of
lights within the system, suited for installation by property owners who are
not
electricians;
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f) a plurality of lights use extra-low voltage, long-life bulbs;
This system of lights that are buried but shining upwards to illuminate trees,
shrubs, and
overhanging can be complemented by having some of the individually dimmable
lights
equipped with housings that each have a ledge and a rim surrounding a lens for
the light.
The ledge and rim are used to support and hold the cylindrical walls of a
column
supporting a mushroom cap shade that captures light energy shining up from the
light
and reflects it downward.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a block diagram showing a system of garden lights using the
invention.
Figure 2 is a schematic diagram showing the electronics of an individual
garden light of
the system of Figure I .
Figure 3 is a top view of an individual garden light of the system of Figure
1.
Figure 4 is a cross-sectional side view of the garden light of Figure 3.
Figure 5 is an exploded cross-sectional side view of the garden light of
Figure 3.
Figure 6 is a side view showing a mushroom cap fitting into the garden light
of Figure 4.
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Figure 7 is a perspective view showing the system of Figure 1 in operation.
DETAILED DESCRIPTION
Referring to Figure 1, the configuration consists of a first individual lamp
1, a second
individual lamp 2, a third individual lamp 3, a fourth individual lamp 4,
connected to a
central primary line voltage control switch 5, by extra-low voltage lines 6,
7, 8. Each
individual lamp 1 - 4 has its own dimmer circuit 9, 10, 11, and 12
respectively.
Referring to Figure 2, the lamp brightness is controlled by a switching
circuit in
integrated circuit (IC) U1 which controls the soft start and varies the duty
cycle of the
power through Q 1. The dimming level is set with screw adjuster pot RV 1 which
is rated
1K 20% 250 mW. This affects the lamp on time and hence the light output. To
minimize
lamp brightness changes with minor Voltage flow variations, the supply Voltage
is
sensed through the divider comprising R9 and Rl 1.
Further electrical components complete the required circuits as shown in
Figure 2. C1,
CS and C6 are 100nF monocap 50 V 20%; C2 is 4,700uF Electrolytic 35V 20%; C3
is
lOuF electrolytic 16 V. Diodes D1 - D4 are 5 amps, 40 V; DS is 12V 5% 500 mW;
D6 is
1 Amp, 40 V. R1 is 1K 5% 500 mW. R2 - Rl l are all 5% 250 mW; with values R2 -
6K8, R3 and R4 - 10K, R5 - 22K, R6 - IOR, R7 - 47K, R8 - 1K2, R9 - 150K, R10 -
2K7,
R l 1 - 4K7. Fuse F 1 is a fast 4 amp fuse, mounted in fuse clip HW 1 on the
dimmer
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control board 20, which comprises a printed circuit board HW2. HW3 is a heat
sink to
dissipate excess heat during operation to allow the components to function
without
degradation due to overheating. Q1 is an FET rated at 60V SSA and Q2 is a
general
purpose transistor 60 V 100 mA A current mode controller at U 1 has a 100%
duty cycle
and is rated to operate in the range of 0 - to 70 degrees C. A microcontroller
is used to
decode the remote control commands, checks the message ID and decides if the
command is for this particular lamp unit. If the command is for another lamp
unit, it is
ignored. Commands for the lamp control are interpreted by the microcontroller
and the
appropriate output signal produced. The microcontroller circuitry at P1 can be
set to
instruct the controller U 1 to perform a "soft" start, whereby the lights
gradually increase
in output until the desired, pre-set brightness of the lights in the system is
achieved. The
radio frequency receiver module RF 1 is connected to the programmable logic
integrated
circuit P 1 to enable a remote control transmitter RC 1 to send commands to
the dimmer
control board 20.
Referring to Figure 3, the lamp has a substantially spherical housing 21,
which is
waterproof, suitable for burying such that only a top portion 22 adjacent to
the lens cover
23 is exposed to shine on the target objects to be illuminated. The lens rim
seal 24 keeps
rain and dust from entering the lamp.
Referring to Figures 4 and 5, the housing 21 has a wire inlet 31, a wire inlet
grommet 32,
adapted to seal around an electrical supply wire and match the waterproof
functionality
of the housing 21, a wire inlet bolt 33, and a complementary nut 34. The wire
inlet bolt
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33 also serves to hold the bottom flange 35 of the dimmer control board 36.
The
dimmer's screw adjuster pot RV1 is set on an upper side flange 36 to enable to
be
positioned behind adjuster aperture 37. A dimmer screw adjuster plug 38 fits
into the
aperture 37 to seal against rain and dirt. A sealed beam light source 39, with
electrical
contacts 40 and 41 fits within the sealed beam cradle 42. The cradle is held
in position in
the housing 21 by means of compression flange 43. The lens rim seal 24 can be
made of
resilient material of a close-fitting tolerance pressed into position on the
lens seal rim
ledge 44. The housing 21 has an optional shade support ledge 71 and shade
holding rim
72, suited to hold a shade wall 73. Thus in place of a flush lens seal, a
mushroom shaped
shade and reflector can be fitted onto the housing 21 as shown in Figure 6.
The
mushroom shade and reflector 51 has a hollow column 52 up which the light from
the
lamp travels. Slots in the column near its top allow the light to then be
reflected down
from the underside 53 of the mushroom-shaped cap 54. The top of the mushroom-
shaped
cap 55 acts as a mof or umbrella to deflect rain, wind, dust, and snow from
falling on the
lamp.
Referring to Figure ?, the individual lamps 1, 2, 3 and 4 are pre-set at
different levels of
brightness. Lamp 1 is set at maximal brightness to illuminate a tall tree 61.
Lamp 2 is set
at a medium level to illuminate a shorter tree 62. Lamp 3 is set at a moderate
level to
illuminate a flower bed 63 via a mushroom-shaped shade and reflector 51. Lamp
4 is
shown buried ax an angle to illuminate an adjacent upright plant 64.
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The extra,-low voltage lines from the transformer to the individual lights can
be more
than a hundred yards long yet provide a consistent pre-selected light level
due to the
dimmer voltage compensation circuit.
As an alternative to having a remote control transmit wirelessly to individual
lamp units'
receiving modules is to transmit control signals down the extra low voltage
lines, which
can thus be used as signal lines as well as electrical power supply lines.
The within-described invention may be embodied in other specific forms and
with
additional options and accessories without departing from the spirit or
essential
characteristics thereof. The presently disclosed embodiment is therefore to be
considered
in all respects as illustrative and not restrictive, the scope of the
invention being indicated
by the appended claims rather than by the foregoing description, and all
changes which
come within the meaning and range of equivalence of the claims are therefore
intended to
be embraced therein.
