Bulb Types: A bulb designation
consists of a letter(s) to indicate the shape and
a figure(s) to indicate the approximate majoy diameter
in eighths of an inch. Bulbs are measured through
their greatest diameter in eighths of an inch. Thus,
an F-15 bulb is a flame shape, 15/8 of an inch or
1 7/8 inches in diameter.
Filament Types: A filament designation
consists of a prefix letter to indicate whether the
wire is straight or coiled, and a number to indicate
the arrangement of the filament on the supports. Prefix
letters include: C (coiled) - wire is wound into a
helical coil or it may be deeply fluted; CC (coiled
coil) - wire is wound into a helical coil and this
coiled wire again wound into a helical coil.
Base Types: Typical screw base is
shown. One leadin wire is soldered to the center contact
and the other soldered or welded to the upper rim
of the base shell. Base shells are typically made
of brass or aluminum. ANSI designations are in parentheses.
Fluorescent
Bulb Types: The bulb shape and size
of a fluorescent lamp are expressed by means of a
code consisting of the letter "T" (which designates
that the bulb is "tubular" in shape) followed by a
number which expreses the diameter of the bulb in
eighths of an inch. They vary in diameter from T-2
(1/4 inch) to T-12 (1 1/2 inches). In nominal overall
length, fluorescent lamps range from 6 to 96 inches,
which is always measured from back of lampholder to
back of lampholder. For example, the actual overall
length of the 40 watt rapid start T-12, 48 inch lamp
is 47 3/4 inches. Circline lamps, which are circular,
are available in four sizes: 6 1/2 inches, 8 inches,
12 inches and 16 inches outside diameter. There are
also U-shaped fluorescent types (curvalume) with T-8
and T-12 bulbs. The width of U shaped types are measured
for the distance between the ends. The overall length
is measured from the face of the bases to the outside
of the glass bend.
Base Types: For preheat and rapid
start fluorescents, four electrical contacts are required,
two at each end of the lamp. This is accomplished
in the standard line of lamps by the use of a miniature
bipin for T-8 and T-12 bulbs and mogul bipin for T-17
bulbs. In circline lamps, the cathodes are connected
to a four-pin base located between the junction of
the two ends of the lamp. High Output and Very High
Output lamps have recessed double ontact (RDC) type
bases. Slimline (Instant Start) lamps require pnly
two electrical contacts, one at each lamp end and
have single pin bases.
All compact fluorescent lamp bases shown have 2 or
4 pins. The 2 pin lamps are designed for preheat operation,
with lamps having an internal starter. The 4 pin lamps
are dimmable and are designed for electronic ballast
operation; these lamps have no internal starter.
H.I.D. (High Intensity Discharge)
Bulb Types: A bulb desingation consits
of a letter(s) to indicate the approximate maximum
diameter in eighths of an inch. Thus, an ED17 is an
Ellipsoidal Shape, 17/8 of an inch or 2 1/8 inches
in diameter.
Base Types: Lamps with screw bases
have one lead-in wire soldered or welded to the center
contact and the other soldered or welded to the upper
rim of the base shell.
Bases with ceramic bodies have internal leads welded
to either silver plated contacts or external lead
wires.
Base Types: Typical screw base is
shown. One leadin wire is soldered to the center contact
and the other soldered or welded to the upper rim
of the base shell. Base shells are typically made
of brass or aluminum. ANSI designations are in parentheses.
