There are basically 2 types of standard light fittings—screw and bayonet. Screw caps are commonly used for domestic lighting purposes. They uses the metal screw as the first contact and the base as the second contact so that the lamp can simply screw into the fitting. The screw, then forms part of both the electrical and physical contact that completes the circuit. Screw cap fittings are very easy to maintain as they require no springs for attachment. However, they have the tendency to cross-thread with the bulb.
Bayonet caps on the other hand, are more popularly used throughout the UK. Bulbs and caps that use this mechanism consists of a spring and two contacts (each with bayonet mounts) on either side. Instead of screwing in the bulb, bayonets simply need to be depressed into the holder and then twisted under the lugs so that the bayonet mounts are held in place by the springs. This ensures optimum contact for efficient electrical conduction.
Bayonet light caps have long been the standard fitting used by former members of the British Empire (UK, India, Australia, Ireland, New Zealand, etc.). Standard bulbs only have two pins on either side of the cap, but specialised bulbs have three (B22d-3 types) so they can't be used in domestic light fittings. Three-pin bulbs are mostly used in mercury street lamps as well as in Fireglow bulbs used in older versions of electric radiative heaters. The most practical use of bayonet cap bulbs is for applications where vibration and movement may loosen screw mounts, such as in automotive lighting and flash lights.
Bayonet capped LED bulbs are now available and designed for many different applications. It is common to find LED bulbs with bayonet fittings in batten holders, pendant lights, ceiling, and wall lights as well as in decorative luminaires. Many automotive light fittings also use the mechanism, preventing road vibrations from loosening the bulb from its socket.
Look for lighting suppliers that specialise in LED lighting if you want to save a great deal on your lighting maintenance and electric consumption. LED products are very cost-efficient and environmentally friendly, making them the best choice for domestic and even commercial and industrial use. Choose shops that offer a wide range of LED products from quality brands to ensure the quality of the items that you will receive.
About The Author:
This article is written by Henry Smith, who is the Marketing Head of LEDSupplies.co.uk. LED Supplies UK is one of the UK's leading retailers of LED bulbs and lights. They have a wide range of highly efficient, affordable, quality LED lighting products. They provide bulbs, lights and spotlights that consume up to 90% less energy and generate more light output than other bulbs.