Introduction:
- Generally we do not aware about which type of socket we need for light Bulb. This is very important while buying a bulb, with the wrong base selection will not fit in the lamp or fixture
- Light bulb bases and sockets are normally defined by a letter-number-letter format, with the last letter optional.
- The first letter designates the shape or form of the base, the numbers represent either the width of the base or the distance between the pins.
- The second letter designates the number of pins or contacts on the lamp.
- The numbers are normally in millimeters. LED light bulb sockets and bases are manufactured to the same standards as halogen, incandescent and other traditional lights.
Type of Sockets:
There are different types of Socket available in market
- Bayonet Cap Base (B)
- Edison Screw Cap Base (E)
- Single Pin Type Base (F)
- Bi Pin or Multi Pin Type (G)
- Cable Connections (K)
- Pre-focused Light Base (P)
- Recessed Contact(s) Base (R)
- Shell-type Light Bulb Base (S)
- Telephone Slide Base (T)
- Wedge Base
- Special Type Light bulb Base (X)
(1) Bayonet Cap (B / BC / SBC):
- Type of Connection: “push and twist” action
- Pin Configuration: (Bxx or BCxx):
- The First letter indicates the shape or Style of the base.
- The Second number indicates the width of the base (normally in millimeters).
- Example:
- The “B” refers to the style of Base which is a Bayonet, and the 22 means it has a 22 mm base width.
- Application: All Regular type of Bulbs including specialist low voltage halogen lamps
(2) Edison Screw Cap (E / ES):
- Named as inventor Thomas Edison, the Edison Screw or “ES” lamp fitting is used in a vast range of applications.
- Type of Connection: “Screw” Action
- Pin Configuration: (Exx or ESxx):
- The First letter indicates the shape or Style of the base.
- The Second number indicates the width of the base (normally in millimeters).
- Example: E26 base.
- The “E” refers to the style which is an Edison screw-in, and the 26 means it has a 26 mm base width.
- Application: Large chandeliers Some Decorative Lamps.
- The most commonly used screw fittings are shown in the table below. Other, less frequently used, sizes include E11, E17 and E26.
Designation | Diameter | Name | Abbreviation |
E5 | 5mm | Lilliput Edison Screw | LES |
E10 | 10mm | Miniature Edison Screw | MES |
E12 | 12mm | Candelabra Edison Screw | CES |
E14 | 14mm | Small Edison Screw | SES |
E17 | 17mm | Intermediate Edison Screw Base | IES |
E27 | 27mm | Medium Edison Screw | ES |
E39 | 39mm | Mogul or Giant Edison Screw Base | GES |
E40 | 40mm | Giant Edison Screw | GES |
(3) Bi Pin or Multiple Pin Type Base (G)
- The “G” type of lamp base is used to as a “pinned” base. This may be several Numbers of different Types of pins.
- Type of Connection: “Pin” Type
- Pin Configuration: (G(U,X,Y,Z) -xx-x-x):
- It is indicate by Letter (or Letters)-Numbers-Optional letter- Letter:
- The first letters includes “G” which is followed by a Second (optional Letter) Letter U, X, Y or Z.
- The second letter (U, X, Y,Z) represents the configuration of the base, which determines the diameter and shape of the pins. For example, pins may be rounded, square, grooved, fat or slender.
- Without any Optional Letter = Base length is 8.25mm and Pin Diameter is 0.7mm
- For Y=Base length is >6mm and Pin Diameter is 0.7mm
- For X= Base length is <7.5mm and Pin Diameter is 1mm
- For U= Base length is >6mm and Pin Diameter is 1mm With One or Two Grip channel.
- For Z=P Base length is >6mm and Pin Diameter is 1mm without Grip Channel.
- The Third number indicates the Distance in millimeters between the centers of each pin.
- The Forth (optional Letter) Letter indicate the number of pins, no letter means 2 pins. d for double Pin ,s for Single pin, t for Triple pin or 3 pins and q for Quadruple pin or 4 pins.
- The Fifth Letter indicates position of Dowel (Slot) in Socket
- Examples: GU10 base type, GU24q 2Pin base type, G13d 3pin.
- For GU24q 2 Socket, U=Pin length is>6mm with diameter 1mm with Grip channel, No of Pin is 4 no’s and Dowel is on Left Side
- Application: Halogen, Compact Fluorescent ,LED Types Bulbs
Difference between G24q-1, G24q-2, G24q-3 Type Socket
- Here G=Type/ Shape of Socket
- 24=Distance between each Pin
- q= Quadruple (Four) Pin.
- 1=Indicate Dowel (Slot) Position ,1=Middle, 2=Left, 3=Right Position
Difference between Gx24, G24 Type Socket
- In Gx24 The Base is smaller while in G24 Base is larger.
Type | Pin to pin distance | Pin Diameter | Typical Bulbs that use this base |
G4 | 4mm | 0.65-0.75mm | MR11 and other small halogens of 5/10/20 watt and 6/12 volt |
GU4 | 4mm | 0.95-1.05mm | |
GY4 | 4mm | 0.65-0.75mm | |
GZ4 | 4mm | 0.95-1.05mm | |
G5 | 5mm | T4 and T5 fluorescent tubes | |
G5.3 GU5.3 GX5.3 GY5.3 | 5.33 mm | 1.47-1.65mm | MR16 and other small bulbs typically using 12/24 volts |
G6.35 GX6.35 GY6.35 | 6.35 mm | 0.95-1.3mm | |
G8 | 8mm | ||
G9 | 9mm | ||
GU10 | 10mm | bulbs using twist-lock bi-pin base | |
G13 | 12.7mm | T8,T10 & T12 fluorescent tubes | |
G23 | 23mm | 2mm | |
GU24 | 24mm | 2 and 4 pin bases with center key | |
GX53 | 53mm | used with puck shaped lamps typically twist-lock |
January 01, 2017 at 10:00AM