Origin of closed circuit
Examples from the Web for closed circuit
There were no closed-circuit television cameras operating in the area near the blast.
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?
The alarm switches are all connected in series in this case and in circuit with a closed-circuit battery and relay or drop.
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.