EEE World, Department of EEE, ADBU: Type of Lighting Bulbs (Shapes and Sizes) Part-1

Introduction:

There are various Shapes of bulbs available in market. Some lamp shape is widely used on other hand some lamp shape is used in special requirements.
If we properly understand bulb codes, it’s easy to select appropriate bulb for a light fixture.
Bulbs shapes are mostly classified according to direction of lights, lighting glare and Bulb size.
Every light bulb has identifying characteristics that are represented by a letter or series of letters and a number, these are known as light bulb codes.

The Bulb Code is indicating as a Letter-Number-Letterformat, the last letter is optional.
The First Letter in a bulb code indicates either shape or special features such as reflector type.
The Second Letter (Number) in a bulb code indicates size of Bulb in millimeters or eighths of an inch .It will tell us whether the bulb will fit in fixture or not.
The Third Letter is optional which indicate Bulb length.
Example: BR30S
First Letter: BR=” Bulged Reflector”
Second Letter = diameter of Light Bulb =30/8 inches, or 3 and 3/4 inches.
We can say that PAR30, R30 and BR30 all have same size bulb.
Knowing the diameter and sizes of these light bulbs is important because in some unique cases the R and PAR are interchangeable as LED bulb replacements.
If in Code there is “S” or an “L” indication in last, that stands for either short neck or long neck.

There are following Shapes of Lamps, Some are very common in everyday uses while some are use in special requirements.
According to Shape:

A Means “Arbitrary”. It shape looks like ordinary Light Bulb.
It is also known as “Classic Globe Type” or “Standard shape Type” Bulb.
Thislamp is the most commonly used as household lamp.
It is normally used in fixtures where the bulb is visible.
It is not known that why it known as A Type. It doesn’t look like an A Shape until we turn it down.
We can assume that this is the first type of light bulb introduce in market hence it called “A” Type.
Nomenclature: A35, A20.
Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.
A15 bulb: 15/8 = 1-7/8″ diameter
Lighting direction: Omni direction.
Bulb Technology: incandescent, LED, CFL.

Application:
Standard / arbitrary (A) bulbs are normally widely used in Household lighting.
These bulbs work well for a variety of applications, such as ceiling lights, lamps, vanity lights, kitchen lights, closet lights, porch light fixtures, Room lighting, Reading lamps, Ceiling Light, Wall Light and Hallways Light. It also used in some chandeliers.

“B” means Blunt-tip.
This is a slimmer version of the Type A Bulb.
The bulb is generally in narrow and bullet shape.
B bulbs are very similar to C-type bulbs but they have a bulged base that tapers to a pointed tip hence look like a torpedo or bullet shape.
It is available in Clear or Frosted(opal)
Nomenclature:
Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.
B10 bulb: 10/8 = 1-1/4″ diameter
Lighting direction: Omni direction.
Bulb Technology: incandescent, LED, Tungsten-halogen, CFL.

Application:
This is most often used for decorative purposes and chandeliers, wall sconces, pendant lights.
It is also used in low wattage applications as a home lighting applications and night lights.

“C” means Conical or Candle and “CA” means Conical Angular.
CA bulbs are shaped like a cone but have a bent tip.
The shape of this Bulb is look like as a candle flame and referred to as candle bulbs.
Candelabra Light Bulbs are similar as B Shaped bulbs but bulb’s tip is bent giving the slight look of a flicking flame.
It is available in Clear or Frosted(opal)
Nomenclature:
Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.
C7 bulb: 7/8 = 7/8″ diameter
Lighting direction: Omni direction.
Bulb Technology: incandescent , LED, Tungsten-halogen , CFL

Application:
These bulbs are common in chandeliers and decorative light strands, holiday light strands, pendant lights, and night lights.
We choose a blunt shape in more contemporary chandeliers if the bulb were seen.
It also use in low voltage application and as s night lights.

“F” means “Flame” .
F light bulbs are similar in size and shape to C Type light bulbs.
However the glass of the bulb is blown or etched in such a way that causes the light to look as though it is flickering like a flame.
This bulb comes with a white finish, but to achieve candle-like appearance, a clear finish is preferred.
If the bulb is colored, a transparent color allows the filament to be visible.
It is available in clear or frosted(opal)
Nomenclature:
Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.
F10 bulb: 10/8 = 1-1/4″ diameter.
Lighting direction: Omni direction.
Bulb Technology: incandescent , LED, Tungsten-halogen , CFL

Application:
F light bulbs are used in decorative applications such as chandeliers, bathrooms, and restaurants and commercial applications..

Application:
Globe light bulbs are used in decorative applications in theatres, restaurants, and hotels
Globe light bulbs are used in a variety of applications where a decorative ball shaped light source is required such as ceiling fans, accent fixtures, kitchen lights, bathroom and makeup vanities, chandeliers, ornamental fixtures and table lamp, wall and floor lamps.