Lamp
A lamp is the component of a headlight, work light, tail light or warning light that produces light. Depending on the technology, the light source may be a separate component that can be replaced, or it may be permanently integrated into the luminaire.
The term is often used generally to refer to various electrical light sources. These include, for example, incandescent and halogen lamps, gas-discharge lamps and LEDs. Technically, however, these light sources differ fundamentally in the way they convert electrical energy into light.
Types of light sources
In a halogen lamp, an electric current heats a tungsten filament to such a high temperature that it emits light. It therefore belongs to the category of incandescent lamps.
Gas-discharge lamps, on the other hand, produce light through an electrical discharge in a gas or gas mixture. A well-known example from vehicle lighting is the xenon lamp.
In an LED, light is generated within a semiconductor. LEDs can be used both as individual, replaceable light sources and as permanently integrated components of a light or luminaire.
The technology used alone does not determine how much usable light a complete light produces or how this light is distributed. In addition to the light source, the optical system, the control system and thermal management, amongst other factors, are crucial in this regard.
Replaceable and integrated light sources
In many traditional vehicle lights, the lamp can be replaced independently of the light itself. The bulb is fitted into a dedicated socket and replaced in the event of a fault.
In modern LED lights, this separation often no longer exists. The LEDs may be permanently mounted on a circuit board and form part of a complete light module. The optics, electronics and heat dissipation are tailored to the LEDs used. In the event of a failure, therefore, a single LED cannot necessarily be replaced as a separate light source.
In addition, there are replaceable LED light sources, for example for certain vehicle lights. Whether such an LED light source may be fitted in place of an originally intended halogen bulb does not depend solely on whether it fits mechanically and electrically into the existing light. For use on public roads, the applicable approval conditions must be observed.
Base and socket
In the case of replaceable lamp, the base provides the mechanical and electrical connection to the light. The shape, dimensions and electrical contacts of the base vary depending on the type of light source.
The base of the lamp is inserted into the corresponding socket. Whilst the base is therefore an integral part of the lamp, the socket refers to the receptacle on the light. Both must fit together mechanically and electrically.