The emergence of solid-state lighting is adding
Lutron Electronics—changed the lighting control
heat to the topic of lighting controls. Energy
landscape by making it practical and affordable
codes, advances in wireless communication,
beyond theatrical use.
intelligent networking and computer interface software are fueling imaginations, while energy
85 IQ – Getting to Practically 'Dim'
cost escalation is exciting customer interest.
In the late 1950s, the ﬁrst solid-state dimmer
Unfortunately, much of the potential from this op-
design for incandescent lamps, developed by GE,
portunity is locked up by proprietary approaches
utilized thyristors or silicon-controlled rectiﬁers
at odds with the diversity of lighting products
to cut portions of the AC sine wave supplied to
necessary to complete projects. Making matters
the light source. This helped reduce light output.
worse are some marketers promoting simple,
A short time later, TRIAC—Triode for Alternating
automatic controls as “smart” further confusing
Current—devices offered lower cost and greater
customers. So it begs the question, just how intel-
durability. Since incandescent lamps suffer only
ligent is solid-state lighting today? Following is a
minor issues with wave cut dimming—some ﬁla-
review of what's out there and the corresponding
ments will sing or ﬂicker a little—this technology
delivered economy and compact size ideal for wall-box dimmer use. This remains the standard
65 IQ – Immature and Intellectually Challenged
for incandescent dimming today.
Lighting control has been a part of lighting from
The introduction of more complex light
the installation of the ﬁrst electric lamp. The ba-
sources, such as low-voltage and discharge sourc-
sic use of on/off switches and contactor controls
es, e.g. ﬂuorescent and HID, presented dynamics
were an early selling feature, eliminating snufﬁng
beyond the capability of TRIAC dimmers. For
gas or oil ﬂames one ﬁxture at a time. At this
inductive loads, MOSFET—Field Effects Transistor
level, little has changed since 1897.
dimmers, which create trailing edge wave cutting,
Dimming emerged as a means to balance and
vs. leading edge for TRIAC—produced acceptable
tune stage lighting. Early forms of the dimmer
results. For ballasted products, however, which
were simple resisters put in series with the lamps,
incorporate starters and lamp current controls
the former consuming as much or more energy
circuitry, special approaches became necessary.
as the loads being controlled. The equipment, too,
This led to the development of two architectures
was too bulky for wide spread use. While early
still in use today: Three wire and 0—10V control.
efforts were hobbled by the technology of the
In the case of the former, power supplied to the
day, the invention of the solid-state dimmer by
light source remains uncontrolled, and a separate
Joel Spira in 1959—who later went on to found
“signal” wire at line voltage is used to communicate
ARCHITECTURAL SSL • 01.13 • 13
Chronicling the Advancement of LED and Solid-State Lighting in the Built Environment.