The base is the part of the lamp that is fixed in the socket and functions both as a mount and as a contact system for connecting electricity. For normal operation, the socket (or other mount) in the lamp must match the base of the lamp. The options used today include, in particular:
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E27 (regular). Standard "Edison" base with a size of 27 mm, used for 230 V lamps in Europe and the CIS countries. If you are looking for a light bulb for a regular home chandelier, floor lamp or socket on the wall (for example, in the bathroom), you will most likely need this type of base. It is also used by many small lamps - table lamps, sconces, etc.
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E14 (minion). A smaller version of the Edison base compared to the popular E27, with a size of 14 mm. It is found much less often, mainly in minion-type lamps, which are distinguished by their small size and elongated bulb. Such lamps are intended for lamps where the use of full-size versions for E27 is impossible or unjustified — in particular, miniature sconces and relatively small chandeliers.
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E40. The largest of the "Edison" bases used in modern lamps, with a size of 40 mm. Used in high-power models, with an LON analogue (see below) of the order of several hundred watts.
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G4. All G-type sockets have two contacts in the form of characteristic pins and diffe
...r in the size of the contacts and the distance between them. In this version, these figures are 0.65-0.75 mm (up to 1.05 mm in some modifications) and 4 mm, respectively.
— GU4. A two-pin base with a 4 mm pin spacing, used primarily in MR11 form factor lamps. These are small lamps with a standard size of 35 mm, usually LED, designed for low voltage — most often 12 V. They are mainly used for spot decorative lighting.
— G5. Standard base for tubular fluorescent lamps. The distance between the pins is 5 mm.
— G5.3. Two-pin base with a distance between contacts of about 5.3 mm and a contact thickness of 1.5 – 1.7 mm. Can be used in lamps of various types and designs, but usually these are 230 V models.
— GU5.3. Two-pin base with standard contact size of 1.4-1.6 mm and distance between them of 5.33 mm.
— G6.35. A two-pin base with a pin spacing of 6.35 mm. Found primarily in halogen lamps.
— GY6.35. Two-pin base with a distance between contacts of 6.35 mm and a pin thickness of 1.2 – 1.3 mm. It is used mainly among halogen lamps, including those with switchable power and voltage, and is found in spot and landscape lighting systems.
— G8.5. A base with two pins that are spaced 8.5 mm apart. Relatively rare, mostly found among metal halide lamps.
— GX8.5. This base is usually used in metal halide lamps for built-in luminaires. Structurally, it is assumed to have a round protrusion and two contacts on the sides. When installed in the socket, the contacts are fixed by turning the lamp.
— G9. Two-pin base with standard 9mm contact spacing.
— GU10. Two-pin base with a standard distance between contacts of 10 mm. Has thickenings on the ends of the pins, designed for fixation in the socket by turning.
— G10q. A specific type of base used in fluorescent lamps that have a ring shape. Incompatible with the original G10.
— G13. Two-pin base with standard contact size of 2.35 mm and distance between them of 13 mm, standard option for most household fluorescent lamps.
— G22. Two-pin base with a distance between contacts of 22 mm. Despite the “closeness” to G23 (see below), it differs significantly from it both in design and in application — it is used mainly in halogen lamps.
— G23. A two-pin base with a standard contact size of 2 mm and a distance between them of 23 mm. It is used mainly in fluorescent lamps with tubes in the shape of an elongated letter U; such models are used in table lamps, as well as some types of wall lamps.
— G24. Slightly larger in size than G23 (see above), the G24 base is used in noticeably larger and, accordingly, more powerful lamps: for example, fluorescent models with such contacts usually have a pair of U-shaped tubes installed in parallel. The main area of application of such lamps are wall and ceiling lights, including industrial ones. Lamps with the G24 base are available in versions G24d-1, G24d-2, G24d-3(with 2-pin contacts) and G24q-1, G24q-2, G24q-3(with 4-pin contacts). They differ from each other in the location and shape of the base.
— G53. The distinctive feature of the G53 base is the use of flat plates instead of pins, as well as the presence of two screws (one per plate) that act as terminals for connecting wires. Such lamps are used, in particular, as built-in lamps; most of them are LED.
— GX24. A base with a characteristic rectangular protrusion and two pairs of contacts located diagonally from this protrusion at a distance of 24 mm. It is used in compact fluorescent lamps (usually with a U-shaped bulb) that do not have a ballast (starting device). There are several versions of this base: GX24q-2, GX24q-3, GX24q-4. The differences between them are in the base format.
— GX53. A base with a round protrusion and two contacts on either side of it. The contacts have thickenings for fixation in the shaped cutouts of the socket by turning the turn (similar to G10). Lamps with this type of base have a flat shape and are designed primarily for installation in stretch and suspended ceilings.
— GX70. The base is similar to the GX53 described above, but differs in the increased distance between the contacts.
— R7s. A socket with a so-called recessed contact: the design includes a recess into which a special pin installed in the socket enters when installing the lamp. Often found in high-power halogen lamps with characteristic elongated bulbs, but can also be used in other types - in particular, fluorescent.
— RX7s. This base has the form of a flat rod with two contacts, one of which is recessed. The RX7s base is found in high-pressure gas discharge lamps.
— 2G7. Four-pin base, used similarly to the G23 described above — in compact fluorescent lamps with U-shaped bulbs. The difference between such lamps and models with G23, in addition to the number and shape of contacts, also lies in some operating features (in particular, they can be used with electronic ballasts, and there is no starter in the design).
— 2G11. A four-pin base consisting of two pairs of contacts, the distance between which in each pair is 11 mm; in fact, a combination of two G-type bases (paired). Rarely used, mainly in compact energy-saving lamps.
— 2GX13. A specialized base designed for ring-shaped fluorescent lamps. It differs from G10q, which has a similar purpose, not only in the shape and size of the contacts, but also in their placement — two pins are located on the outside of the ring, two — on the inside.
— B15d. Another type of bayonet cap, similar to the B22 described above, but with smaller dimensions. Also known as SBC — “Small Bayonet Cap”, that is, “small bayonet cap” (as opposed to the “large” B22 and its varieties).
— B22. A round base with a size of 22 mm, similar to the E-type mounts (see above), but without a thread — instead, two pins are used, which are fixed in the socket cutouts during installation of the lamp using the so-called bayonet method. In addition to the fact that such a mount is quicker to connect and disconnect than a threaded one, it has another important advantage — the ability to withstand constant vibrations without loosening. Due to this, B22 has found application, in particular, among luminaires installed in transport.The service life of the light source claimed by the manufacturer is implied, during which the illuminator is able to generate the claimed brightness and temperature colour spectrum. It is believed that light-emitting diode (LED) bulbs have the longest service life — their working life can be 10,000 — 50,000 hours (
50 years of operation), depending on the modification of the bulb. But this parameter cannot be regarded as a guarantee, since
a lamp with an operating time of 25 years can work less, and maybe even more, than
a lamp with a "life" of 30 or even
35 years. In second place are energy-saving fluorescent light bulbs that are capable of generating daylight — the service life of such is in the range of 2000 — 20,000 hours. The average service life of halogen bulbs is about 2000 — 4000 hours, but when the power supply is equipped with a soft start device, it can be almost doubled. In last place are classic incandescent bulbs, the service life of which is within 1000 hours.
