The base of the
lamp
serves a number of purposes. Different shaped bases are suited to the housings of the various luminaires. The base, through which the electric current flows to the filament, contains a thermal alloy fuse which automatically stops the operation of the
lamp
when the
temperature
rises above normal operating temperature. This could be the result for instance of a damaged
lamp
housing or of a luminaire operating the
lamp
at inappropriately high voltage. Lamp bases used in the theatre lamps are designated by codes.
