In a control system, what does a 'manually-operated circuit' typically require?

A manually-operated circuit fundamentally relies on human intervention to initiate or manage its operation. This means that an operator must physically manipulate controls, switches, or levers to activate the circuit, distinguishing it from automatic systems that operate independently based on sensors or pre-programmed settings.

In contrast, automatic sensors, continuous power supplies, and digital programming typically support automated control systems where machines and systems self-regulate without direct human effort. The dependence on manual input underscores the essential role of the operator in controlling the circuit's functions, thereby emphasizing the interactive nature of such systems.