A twofer is a cabling device used in
theatrical stage lighting
Stage lighting is the craft of lighting as it applies to the production of theater, dance, opera, and other performance arts. . It allows two
stage lighting instrument
Stage lighting instruments (lanterns, or luminaires in Europe) are used in stage lighting to illuminate theatrical productions, concerts, and other performances taking place in live performance venues. They are also used to light television st ...
s to be connected to one
circuit
Circuit may refer to:
Science and technology
Electrical engineering
* Electrical circuit, a complete electrical network with a closed-loop giving a return path for current
** Analog circuit, uses continuous signal levels
** Balanced circu ...
. It is wired in
parallel
Parallel is a geometric term of location which may refer to:
Computing
* Parallel algorithm
* Parallel computing
* Parallel metaheuristic
* Parallel (software), a UNIX utility for running programs in parallel
* Parallel Sysplex, a cluster of IBM ...
, such that
voltage is unchanged in the twofer, and
current is split and divided over two connectors. Twofers are used in conjunction with cables with the same types of connectors.
[theatrecrafts.com glossary](_blank)
/ref>
The name is a corruption of the phrase "Two For One".
UK terminology
The UK equivalent of the twofer is a Grelco. The name derives from the manufacturer of the original examples, but is now generally adopted for all examples regardless of manufacturer. It typically relates to a splitter for the UK 15 A power connections commonly used for stage lighting. It is usually an integral block rather than a plug with two cables leading to two sockets. Where a single plug goes to three or more sockets it is sometimes known as a Trelco.[http://www.shepperd.co.uk/glossary/pages/Lighting/Cables_and_Distro/ ]
Typically for most other power connector types used in theatre, the term ''(2-way) splitter'' is used.
Australian terminology
For several decades, much rock-and-roll and other lighting used "Par Cans", each containing a 120-volt PAR 64 lamp. As the mains supply is 240 volts these must be connected in series, via an adapter lead or box featuring two sockets.
Notes
Stage lighting
{{stagecraft-stub