Closed circuit can refer to:
*
Closed-circuit television
Closed-circuit television (CCTV), also known as video surveillance, is the use of closed-circuit television cameras to transmit a signal to a specific place on a limited set of monitors. It differs from broadcast television in that the signa ...
*
Closed-circuit radio
A closed-circuit radio is a radio that emits over a very small range, typically a college campus. This system can be achieved from two ways:
*By tying into the PA System
*By using existing power lines, telephones lines, pipes, etc. to transmit a c ...
*Closed circuit breathing apparatus, commonly known as
rebreather
A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's exhaled breath to permit the rebreathing (recycling) of the substantial unused oxygen content, and unused inert content when present, of each breath. Oxygen is a ...
s for portable units, and as component parts of
life-support system
A life-support system is the combination of equipment that allows survival in an environment or situation that would not support that life in its absence. It is generally applied to systems supporting human life in situations where the outside ...
s for more complex equipment.
*
''Closed Circuit'' (1978 film), a 1978 Italian film
*
''Closed Circuit'' (2013 film), a 2013 British thriller film
*An
electric circuit
An electrical network is an interconnection of electrical components (e.g., battery (electricity), batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e. ...
is a "closed circuit" if it contains a complete path between the positive and negative terminals of its power source
*
''Closed Circuit'' (album), a 2001 album by New Zealand composer Peter Jefferies
* ''
The Closed Circuit'', a 2013 Polish action film directed by Ryszard Bugajski
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