Check out the journey of LEDs from a red dot to light bulbs and much more. LED lighting systems are widely used as utility savings for companies and offices. prosourcepower.com

1. LED
EVOLUTION

2. Light-emitting diodes are tiny devices
made from semiconductor materials
that convert electrical energy into
visible and near-UV wavelengths —
and some heat — when they are
assembled in a package and connected
to an electrical circuit.
What
IS
LED

3. In 1907, British researcher
Henry Joseph Round noticed
for the first time -when a
potential of 10 volts is
applied to carborundum
(silicon carbide) crystal, it
emits yellowish light.
W H E N I T A L L S T A R T E D -

4. A dopant is introduced to the
semiconductor to determine the colour of
the LED. The mixture used in the first LEDs
-- gallium arsenide phosphide -- produces
a natural red color. That’s why red became
the default color choice for so many
indicator lights.
W H Y T H E F I R S T L E D W A S R E D ?

5. LED FOUND A
HOME IN
CALCULATORS
Low-power LEDs began replacing
incandescent bulbs in electronics,
The prices for those electronics fell
into a much more consumer-
friendly range.

6. THE LED WATCH
The centuries-old art of watchmaking also
felt the presence of the LED when, in 1972,
Pulsar introduced the first LED watch.
Dubbed the Time Computer.

7. I n 1 9 9 3 , S h u j i N a k a m u r a h a d a
b r e a k t h r o u g h i n d o p i n g t h a t l e d
t o b r i g h t b l u e L E D s . B l u e L E D s
w i t h y e l l o w p h o s p h o r c o a t i n g s
g a v e u s t h e w h i t e L E D a n d a
w i d e a r r a y o f a p p l i c a t i o n s . A s
L E D s g r e w b r i g h t e r , t h e
f l a s h l i g h t i n d u s t r y s w i t c h e d t o
L E D l i g h t s . T h e f l a s h l i g h t s u s e d
l e s s p o w e r , a n d t h e b u l b s n e v e r
h a d t o b e r e p l a c e d .

8. OPTICAL
MOUSE
Microsoft introduced the optical mouse in 1999, the
mouse used sensors in addition to LED to track the
movements of the mouse on any surface.

9. Any lamp failing to meet the
energy standards set by EISA
in 2007 could no longer be
manufactured. Tungsten-
filament incandescents lamps
were the most affected by
EISA. LEDs bulbs are the most
energy efficient option,
available in many
color variants.

10. URBAN PLANNING
In recent years, LEDs are used for
street lights and other outdoor
lighting purposes. Individually
focused lights used on the bridge
between San Francisco and Oakland
don’t cause windshield glare of
standard streetlights is one such
example.

11. P R O S O U R C E P O W E R . C O M
THANK YOU