Translation guide
A closed circuit is a complete electrical path or a system where signals or fluids circulate without being open to the outside. In Japanese, the translation depends on whether you mean an electrical circuit, a TV system, or a fluid system.
A complete, unbroken electrical path through which current can flow.
A TV system where signals are not publicly distributed but monitored privately, often for security.
A system where a fluid or gas circulates without being exposed to the atmosphere.
Used for closed-loop systems in engineering, such as hydraulic or cooling systems.
When referring to security cameras, do not directly translate 'closed circuit' as 閉回路. Use 監視カメラ or 防犯カメラ instead. 閉回路 is only for electrical circuits.
Standard technical term for a closed electrical circuit.
When the switch is turned on, a closed circuit is formed.
More descriptive phrase meaning 'closed circuit', used in explanations.
A closed circuit is necessary for current to flow.
Loanword from English, used in some technical contexts but less common than 閉回路.
This device operates on a closed circuit.
Most common term for security cameras, literally 'surveillance camera'. Often used even when the full system is meant.
Closed-circuit cameras are installed in the store.
Literally 'crime prevention camera', often used interchangeably with 監視カメラ for security CCTV.
Check the closed-circuit camera footage.
Direct loanword for 'closed-circuit television', used in technical specifications but rarely in everyday speech.
This building has a closed-circuit television system installed.
This cooling system is a closed circuit.
Emphasizes that the circuit is sealed or airtight.
The refrigerant circulates in a closed circuit.