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.
Standard technical term for a closed electrical circuit.
スイッチを入れると閉回路が形成される。
When the switch is turned on, a closed circuit is formed.
More descriptive phrase meaning 'closed circuit', used in explanations.
電流が流れるには閉じた回路が必要です。
A closed circuit is necessary for current to flow.
Loanword from English, used in some technical contexts but less common than 閉回路.
この装置はクローズド回路で動作する。
This device operates on a closed circuit.
A TV system where signals are not publicly distributed but monitored privately, often for security.
Most common term for security cameras, literally 'surveillance camera'. Often used even when the full system is meant.
店内には監視カメラが設置されている。
Closed-circuit cameras are installed in the store.
Direct loanword for 'closed-circuit television', used in technical specifications but rarely in everyday speech.
このビルにはクローズドサーキットテレビが導入されている。
This building has a closed-circuit television system installed.
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.
この冷却システムは閉鎖回路になっている。
This cooling system is a closed circuit.
Emphasizes that the circuit is sealed or airtight.
密閉回路で冷媒が循環する。
The refrigerant circulates in a closed circuit.
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.
Literally 'crime prevention camera', often used interchangeably with 監視カメラ for security CCTV.
防犯カメラの映像を確認する。
Check the closed-circuit camera footage.