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By Michael Day
Power Management Application Supervisor, Texas Instruments
REPLACE INCANDESCENT LIGHTING WITH LEDs — AN EASY HOME
CONVERSION
This article shows how to replace
standard incandescent lighting with LED
based lighting. The design operates from
standard 120V household power and
uses a standard laptop AC adaptor to
generate a useable DC voltage. This
article covers how to convert a standard
constant voltage power supply into a
constant current power supply that
powers two 1A LEDs, and also touches
on some key design considerations. It
shows the final assembled system, as well
as the yearly power savings achieved
when replacing incandescent bulbs.
ABSTRACT
Accent lighting like that in curio cabinets typically
uses specialty incandescent light bulbs. These bulbs are
expensive, consume a considerable amount of power, and
generate significant amounts of heat — and ultimately are
being phased out by the government. These traditional
incandescent bulbs can easily be replaced with a system
made from a spare laptop AC adaptor and high brightness
LEDs. This design saves energy, enhances ambiance, and
eliminates frequent replacement of
expensive incandescent specialty
bulbs.
MEET THE
COMPONENTS
Figure 1 shows the system
components. An unused laptop AC
adaptor is an ideal choice for the
AC/DC converter. They are
inexpensive and readably available,
probably lying around in a box
waiting to be thrown away. They
provide the power conversion from
the standard 120 VAC household
power to a safe DC voltage level
that is easily connected to an
■ FIGURE 1. System components.
30
November 2011
