Closed circuit can refer to:
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Closed-circuit television
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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
A public address system (or PA system) is an electronic system comprising m ...
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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 substantially unused oxygen content, and unused inert content when present, of each breath. Oxygen is ...
– breathing sets
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''Closed Circuit'' (1978 film), a 1978 Italian film
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''Closed Circuit'' (2013 film), a 2013 British thriller film
*An
electric circuit
An electrical network is an interconnection of electrical components (e.g., batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e.g., voltage sources, ...
is a "closed circuit" if it contains a complete path between the positive and negative terminals of its power source
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''Closed Circuit'' (album), a 2001 album by New Zealand composer Peter Jefferies
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