The base of the light bulb is used to install it in the cartridge. This structural element is made of metal, sometimes ceramics. It consists of filaments (inside) and contacts (located outside). It is he who provides the connection of the lamp itself with a source of electricity.
Types of plinths
The whole variety of products can be divided into the following groups:
- Screw (threaded). Used in conventional incandescent lamps, halogen, fluorescent, gas discharge, LED. The most popular - with a diameter of 27 mm or 14 mm.
- Pin (pin). They are installed on capsule-type halogen lamps, fluorescent, including linear, energy-saving diode lamps. Light sources with G4 base type are the most popular.
- Special. Made for a specific use. Used, for example, in car headlights.
The most common are screw and pin types of socles. By purchasing one or another lighting device for one of the types of products, the client has the opportunity to choose any type of light bulb, depending on their needs. Cantake into account the price, light temperature, power, light output.
Marking
Socles have different contacts, sizes. All this is indicated when labeling the product itself. It can also determine the type of light bulb. Each lamp is equipped with certain cartridges. Carefulness when choosing a light bulb with the right parameters will help to avoid unnecessary spending.
A well-developed notation system will help you navigate. The first capital letter indicates the product type. Further, the digital parameter defined for each type in millimeters is indicated. The subsequent lowercase letter determines the number of contacts (plates, pins). A clarifying marking is provided indicating the energy-saving light bulb (U) or its specialization (A - automotive). May indicate a specific plinth appearance (V-shaped, conical).
Marking in Latin letters and Arabic numerals is international. This will help you choose the right products from both a domestic manufacturer and, for example, Philips lamps.
Types of plinths
There are several types of plinths:
1. Threaded - E. Invented in 1909 by Thomas Edison, and named after him. For many years, nothing has been invented for a more convenient and quick connection of a lighting device to the mains. Until now, this type of base is very popular, it has been adapted for almost all types of modern lamps.
2. Pin - G. They also put on miniature halogenlight bulbs and large ceiling fluorescent. G4 (base) is popular. Most often it is used in lamps for spot ceiling lighting and in flexible systems. The distance between the contacts of 4 mm allows them to be used in miniature lamps. They, in turn, are very much in demand in decorative lighting design because of their bright point light. The number, thickness and shape of the pins can be different. The halogen lamp (G4 base) has a long service life of over 2000 hours. This service life makes it attractive to the consumer. The base letter indicating the G base type is followed by another Latin letter U, X, Y, or Z. These are design modification indicators and cannot be interchanged:
- U - energy saving;
- X - most often used for lamps in spotlights with directional light (indispensable in plasterboard ceilings);
- Y and Z - very rarely used for narrow-purpose lamps.
In table lamps for compact lamps, 4-pin bases are made. To indicate such a construction, the number 2 is written before G.
3. With one pin - F. The contact part of the pin must be insulated from the body, made of conductive material. It belongs to a separate type, which, in turn, differs in the type of pins:
- cylindrical shape – a;
- corrugated – b;
- special form – c.
4. With recessed contact - R. They put such bases on high power lamps andtemperature. As a rule, these are quartz or halogen lamps. Small, light, powered by 220 volts.
5. Pin (Bayonet) - B. A feature of this design is the presence of side contacts. They are divided into types of socles with a symmetrical and asymmetrical arrangement of pins (BA marking). They give the lamp a strictly defined position in the cartridge, this ensures the focusing of the light flux. It is considered a variation of the Edison base with a pin design, which makes it quick and easy to change the light source.
6. Soffit - S. In such a base, the contacts are located on opposite sides of the lamp. The numbers on the marking indicate the diameter of the case. Such lamps illuminate license plates of cars.
7. With cable connection - K. Classified as non-standard light bulb base and used in various projection products.
8. For xenon lamps - H. Like a base with a cable connection, it is considered non-standard. Such lamps have high color rendering and are widely used in stage lighting, optical instruments, and installed in car headlights.
9. Focusing - P. It has a built-in lens that focuses the light flux in a given direction. They are used in film projectors, searchlights, flashlights, in the high beam headlights of cars. The numbers on the marking indicate the size of the diameter of the focusing flange or part of the base.
10. Telephone - T. Such products are used in bulbs to illuminate the dashboard of a car, on control panels, as indicators. Numerical marking suggests the outer width, measured on the contact plates in millimeters.
11. If the current inputs are located directly on the glass base of the lamp - W. In them, in fact, direct contact of the current inputs with the cartridge occurs, such lamps are also called "baseless". First, the total thickness of the glass part with one current bushing is measured and marked, and then, after the multiplication sign, the width of the base of the base is indicated in mm.
The number following the letter indicates the size of the plinth. This can be either its diameter, if it is a threaded type, or the distance between the contacts.
Number of contacts
The number of contacts can be different, the small letter of the Latin alphabet indicates their number:
- one – s;
- two – d;
- three – t;
- four – q;
- five – p.
Additional information
But that's not all the information. Additionally, marking can be applied with some clarification:
- energy saving – U;
- automobile – A;
- with a tapered end at the plinth – V.
Thus, the inscription E26U will mean that this is an energy-saving lamp with a threaded base diameter of 26 mm.
Philips lamps are in great demand - the leader in the production of modern light sources, distinguished by quality and environmental friendliness.
Plinth versatility
Currently, the following types of lamps are produced by the industry:
- incandescent bulbs;
- halogen;
- fluorescent;
- LED.
It is wrong to assume that a strictly defined type of base is used for a specific type of light bulbs. Their new types are being developed and introduced along with the development of the entire lighting industry. The same models can be used in lighting devices that differ in principle of operation, purpose and size.
G4 base specification
If we look at the G4 model in more detail, we can note that the distance between the pins is 4 mm, their length is 7.5 mm. The diameter of the pins cannot be less than 0.65mm and greater than 0.75mm.
G4 Halogen bulbs
Halogen lamps with a G4 base, due to their small dimensions, are often used in products made of various types of glass, including crystal. The bright light from the lamps makes the pendants on the chandeliers shimmer and sparkle like diamonds. Reliability of work is provided with a lamp base. G4 - always high-quality connection of the light source to the electrical network.
When installing halogen bulbs, care and attention is required. Do not touch the surface of the product with bare hands. Gloves are required to avoid leaving greasy marks. Otherwise, handprints will be baked onto the surface of the lamp due to the high temperature, which will reduce the light quality.
Since 2013, LED lamps with G4 (base) have entered the market. They are able to replace halogen lamps with the same base,especially where low voltage is used.
A distinctive feature of LED lamps can be called their ability not to generate heat, in other words, they do not heat up. Compared to halogen bulbs, LED lamps consume less energy and last longer.
Development of a G4 base for this type of light source by specialists will help ensure reliable and cheap operation of lighting devices for various purposes.
G4 LED bulbs
Marking G4 220V suggests that the lamp base G4, 220 volts - operating voltage. Such miniature LED bulbs are widely used for spot lighting equipment. Bright directional light is also used in the manufacture of furniture, whether it is a kitchen set or a built-in wardrobe.
The small dimensions of LED lamps with G4 (base) allow them to be used in flexible lighting systems. Another caveat: they can be of different colors. You can also choose a combination of several shades to emphasize the design style or draw attention to advertising.
The appearance of the lamps can be in the form of a thin plate (round or rectangular) with several LEDs.
G4 Benefits
G4 (base) allows you to quickly and effortlessly change the light bulb. The reliability of the design will not allow the base to fall off from it, as in the screw counterpart. The simplicity of the design allows it to cope with the task of replacing any adult or teenager.
In hard-to-reach places of installationthis design of the base will provide a simple and reliable connection to the power source: the pins just need to be inserted into the cartridge, there is no need to turn or otherwise fix the base. The pins serve as both a mount and current conductors.
Flaws of G4
This can more be attributed to the shortcomings of the G4 cartridge (base). Poor-quality material from which the contacts in the cartridge are made, or poor assembly lead to contact failure. The light bulbs in the lighting fixtures go out, and if they are “moved” a little, they light up again. This indicates that the light source itself is OK, but poor, intermittent contact between the socket and the base.
Lighting fixtures made in China or small firms that do not have a name in the market suffer from such a disadvantage.
