Checking Cap Fittings Before Buying Bulbs – Certain Lamps Require Certain Bulb Types
If you look closely at your light bulb you will see that it has a metal base, this is the part of the bulb or light fitting that connects to the electricity supply and is generally known as the cap or base. This provides the contact that enables the power to flow and the light to work.
There are an enormous amount of different types of caps and this may seem to complicate things unnecessarily but there is a very good reason for it. It is so that only the correct bulbs can be fitted to the corresponding light fitting, preventing mistakes that could cause a fire hazard. It might seem confusing but once you know your way around the types normally used then it is quite straightforward.
Let us look more closely at the most common of these fittings found all around the home.
Probably the most common is the bayonet cap fitting. This has a push and twist action where two small clips on either side of the lamp base slot into place to hold the bulb firmly in position. There are generally two different sizes in this category that are used around the domestic household, 22mm and 15mm, but specialist fixtures may use other sizes.
Then there is the Edison screw type of light bulb, named after Sir Thomas Edison the pioneering inventor of the light bulb. This has a screw fitting that is easy to use and fit. It comes in many sizes from 5mm to perhaps 40mm and is used in many types of light fittings from general lamps to chandeliers where many small bulbs are used to create the desired effect.
In many low voltage lights a halogen bulb is used and again these can come is several sizes and may differ in size and shape from the normal looking bulb. Some are like small capsules with connectors on the end and some are like long tubes of glass again with connectors at one or sometimes both ends.
There are also low voltage LED spotlights and these normally have two small push fit prongs to make the connection required, but sometimes they can be screw fit. These are now widely used in many light fitting around the home because although they can be expensive they are extremely cost effective as they last a very long time.
So, bearing all this in mind it is best to make sure you know which type of bulb fitting your light takes before you set off for the shops as it can be very frustrating to get home with the wrong one.
If you have any manufacturers instructions on your appliance that should tell you what type of bulb you will need and always stick to recommended bulb wattage for safety reasons. The packaging of all light bulbs will carry an information label that provides you all the help you may need.