What is a type A light bulb.

Lightbulb - what types are there?

Types of lamps

Basically, lamps can first of all be divided into "large" categories:

  • classic incandescent lamps (banned today)
  • Halogen lamps
  • Energy saving lamps
  • Led Lamps

Classic light bulb

This type of lamp, which has been used unchanged for over 100 years, has been banned in the EU since 2012. They are no longer available in stores. The reason for this is their inefficiency:

Classic light bulbs consume huge amounts of electricity, as they only convert around 5% of the energy they consume into light. The rest is lost as waste heat. Modern light sources require almost 80% less electricity to generate the same amount of light.

Halogen lamps

Halogen lamps are basically just light bulbs with a special protective gas filling. This protective gas filling (made of halogens such as bromine or iodine) makes it possible to heat up the filament more intensely and thus make it shine brighter. In operation, however, they are no more efficient than conventional light bulbs.

They are currently not banned, but in 2018 there will finally be a ban on high-voltage halogen lamps. They are then replaced by LED light sources.

Energy saving lamps

Energy-saving lamps are so-called compact fluorescent lamps - that is, they work in principle similar to a neon tube. They are still widespread, but they have some serious drawbacks that should not be overlooked.

Led Lamps

LEDs work with special diodes - so-called light emitting diodes (hence the name LED). Here, light is generated with a semiconductor that has an electron-rich and an electron-poor side. When a voltage is applied, the electrons migrate from one side to the other, and the energy released during the subsequent recombination process then becomes visible as light radiation.

Standardized socket types for light bulbs

Each light bulb must fit into a specific lamp socket (screw socket) or plug connection. Accordingly, there are certain standardized sizes that are identified with letter-number combinations.

With the screw mounts these are:

  • E14 (14 mm diameter at the bottom of the lamp)
  • B15 (15 mm diameter at the bottom of the lamp)
  • E27 (27 mm diameter at the bottom of the lamp)
  • B22 (22 mm diameter at the bottom of the lamp)
  • E40 (40 mm diameter at the bottom of the lamp)

With halogen lamps there are different plug connections, which can also look different. The number here indicates the distance between the two plugs.

  • GU10
  • G9 or GU9 (both names are common)
  • GU6.35 or GY6.35 (both names are common)
  • GU5.3
  • GU4 or G4 (both names are common)
When buying a light bulb, you can simply use the code of the socket as a guide. If you can no longer see it on the old lamp, all you have to do is measure it.