Which component converts energy forms in the control system?

• A. Transducer
• B. Sensor
• C. Controller
• D. Transmitter

Answer: (A)

Converting energy from one form to another is what a transducer does in a control system. In practice, the process provides a physical quantity such as pressure, temperature, or displacement, which is a form of energy. The transducer takes that energy and converts it into an electrical signal (voltage or current) that the controller can read and work with. This energy-form conversion is essential for the loop to function because the controller makes decisions based on electrical signals representing the process state.

A sensor is a device that detects a physical property and may be part of a transducer, but the key action here is energy conversion. The controller handles processing and decision-making rather than converting energy forms. The transmitter moves the signal from one place to another, often without changing the energy form, so it doesn’t perform the energy conversion itself. Therefore, the component that converts energy forms is the transducer, such as a pressure transducer that turns pressure into an electrical signal for the control system.