closed circuit

a circuit without interruption, providing a continuous path through which a current can flow.

Compare open circuit.

Origin of closed circuit

First recorded in 1820–30

closed-cir·cuit, adjective

There were no closed-circuit television cameras operating in the area near the blast.

Terror Strikes India |Sudip Mazumdar |September 7, 2011 |DAILY BEAST
Closed-circuit footage from a nearby shop shows at least three other security personnel simply standing by.

Punjab Governor Salmaan Taseer: Mourning Pakistan's Slain Leader |Fasih Ahmed |January 4, 2011 |DAILY BEAST
Is writing simply a borderless act or can we ascribe a closed-circuit origin to it?

Do National Writers Still Exist? |Colum McCann |November 28, 2010 |DAILY BEAST
The alarm switches are all connected in series in this case and in circuit with a closed-circuit battery and relay or drop.

The Boy Mechanic, Book 2 |Various

This is a highly efficient form of closed-circuit magnet, since the magnetic circuit is of low reluctance.

Cyclopedia of Telephony & Telegraphy Vol. 1 |Kempster Miller
Three days later Joseph Dixon slid a closed-circuit message plate across the desk to his boss.

The Variable Man |Philip K. Dick
But a play-back recorder named Al, and a picture-unscrambler named Gus were in closed-circuit relationship with Betsy.

The Machine That Saved The World |William Fitzgerald Jenkins
An ordinary telegraph relay may be used in connection with the closed-circuit alarm.

The Boy Mechanic, Book 2 |Various

closed circuit

a complete electrical circuit through which current can flow when a voltage is applied Compare open circuit

closed circuit

An electric circuit through which current can flow in an uninterrupted path. Compare open circuit.

A television system in which the signal is usually sent by cable to a limited number of receivers.