2. Introduction to the Electrical
breakfast club
Weekly 20-30 minute topic of electrical interest.
Open and informal
All information can be found on
TESEngineering/Electrical breakfast club/date
outline of weekly topic
Links (if applicable)
Additional reading (if applicable)
Power point presentation (if applicable)
3. Lighting Sources
History
First lighting sources can date back to
3000 BC. Egyptians used hollowed out
stones filled with fat, and plant fibers for
wicks.
Beats the code The code of Hammurabi.
Created circa 1760 BC, Mesopotamia. (first
building code)
Greeks and Romans used Oil lamps.
(animal fat) In the late 1700’s kerosene
became widely used.
4. Lighting Sources
History
In the 1800’s gas lamps were popular for
street lamps. In the late 1800’s/early
1900’s the electric lamp took over. 1879
Edison’s patent for the electric lamp.
Modern day lighting includes: mercury
vapory lamp in the 1930’s. (no longer
used). Fluorescent lighting debuted at
the 1939 world fair, tungsten-halogen
was introduced in the 1950’s, and metal
halide and high pressure sodium in the
1960’s. In the 1990’s LED were
introduced.
5. Types of light sources
Incandescent
Fluorescent
High Intensity Discharge (HID)
Light Emitting Diodes
LED is an exciting new development
in the lighting industry. Would not
have made the list a couple years
ago.
6. Incandescent Filament and
Tungsten-Halogen lamps
Light is produced by electric current passing through
a filament that “glows”.
a.
b.
Components include base, bulb, and filament.
Normal filaments are made of lead. TH lamps have a
filament made of tungsten and the lamp compartment is
filled with halogen gas for better color and lamp life.
7. Incandescent pros and cons
Pros
1. inexpensive fixture and lamp
2. instant on/off
3. Dimmable. Dimming significantly increases
lamp life. 90% voltage = 10 times lamp life.
4. Wide variety of lamps and distributions. Par 20’s/par
30’s/par 38’s/ MR 16’s/quartz.
5. Great color.
6. Good lower wattage point source.
Cons
1. Not efficient. High energy usage. 1200 lumens 75W/A19 (16 lumens/watts)
2. poor lamp life. 75W/A19 750 - 2000 hours. 166
days on 12 hour burn.
3. Only available for 120 volt use.
8. Fluorescent and Compact
Fluorescent
Light is obtained by producing an arc in a lamp
filled with gas (mercury vapor) between 2
electrodes. The arc excites the phosphor coating
on the inside of the lamp. Voltage is regulated by
a ballast.
Components include base, bulb, and electrode.
Compact fluorescent lamps are smaller in size
and have one base.
9. Fluorescent pros and cons
Pros
1. instant on/off
2. efficient light source. Electronic ballast really made the
difference.
2060 lumens – 32WPLT (64 lumens/watt)
3. Dimmable. With dimming ballast.
4. Wide variety of lamps and distribution. Compact fluorescent
lamps continue to drive higher wattage/smaller fixtures.
5. Good color.
6. Great lamp life. 24000 hours. 2000 days on 12 hour burn.
7. Good lower wattage point source (compact fluouresecnt)
Cons
1. Fixture cost slightly higher due to ballast.
2. Dimming is more expensive.
3. Not a good high wattage point source. Need a lot of 4’ lamps
to produce high amount of lumens.
4. Can be 120 or 277 volt
10. High Intensity Discharge (HID)
Light is produce by an arc discharge contained in an
arc tube inside of a bulb. (bulb inside a bulb).
Voltage is regulated with a ballast. Types include
mercury vapor, high pressure sodium, and metal
halide. Different gases in the lamp to produce
different efficacies (lumens/watts) and color
rendering (CRI) higher color rendering brings out
more color. Mercury vapor - 15. High pressure
sodium – 22. Metal halide – 65. Ceramic metal
halide – 85. (fluourescent is around 82)
Components include base, outer bulb, and arc tube
chamber.
11. High Intensity Discharge pros and cons
Pros
1. efficient light source. Electronic ballast making
efficiency even better. 32000 lumens – 400W
MH (84 lumens/watt)
2. Very good lamp life. 15000 – 20000 hours. 1666
days on 12 hour burn
3. Good color. If a more expensive lamp is selected.
4. good point high wattage point source. Work well in
high ceiling applications.
5. Can be 120 or 277 volt.
Cons
1. Lamp needs to “warm up” to strike. (gas in arc tube
needs to ionize) Has re-strike time if power
blips. Therefore fixture cannot be used for
emergency lighting.
2. lamps are larger, therefore fixture are larger.
3. Color was a problem, but getting better.
12. Light Emitting Diodes (LED)
Light is produced by driving current through a semiconductor device.
Components include semi-conductor device and
driver
13. LED Pros and Cons
Pros
1. Great efficiency
2. Lamp life is 100,000 hours 22 years on 12
hour burn.
3. Became cost effective when the price of
semiconductors fell.
Cons
1. Need a lot of LED’s to produce light.
Therefore fixture
gets big
2. Consistency of LED is an issue
3. New technology – still relatively expensive.
