What is the role of a transformer in control circuits?

• A. Step voltage up or down, provide isolation between circuits, and impedance matching to protect components and optimize performance.
• B. Generate energy.
• C. Convert DC to AC.
• D. Store energy.

Answer: (C)

A transformer in control circuits is used to transfer AC power or signals between parts of a system while changing voltage levels and providing isolation. It works by mutual induction between the primary and secondary windings, which allows stepping voltage up or down and matching impedances between stages. This helps protect components, minimizes noise and loading effects, and ensures the controller or sensors see appropriate voltage levels. Transformers rely on changing magnetic flux, so they only operate with alternating current; they cannot convert DC to AC—that task is handled by an inverter. They also do not store energy; that function belongs to components like capacitors or inductors in storage or filtering roles.