Which symbol is used to represent a relay in TPC schematics?

The symbol that represents a relay in TPC schematics is indeed a rectangle with contacts indicated. This representation effectively captures the essential components of a relay, which includes the relay coil and its associated contacts. The rectangular shape typically symbolizes the relay itself, while the additional lines showing contacts demonstrate how the relay interacts with the circuit, indicating whether the contacts are open or closed based on the relay's energized state. This clear visual representation helps anyone reading the schematic to easily identify the function of the relay and its role within the electrical system.

In contrast, other symbols do not specifically represent a relay. A rectangle with a diagonal line might denote a different type of component, potentially a fuse or a circuit breaker. A circle with a square inside could symbolize generic electrical components but lacks the specificity needed for relays. An oval with a spring symbol may be used to depict other types of devices or mechanisms, but does not accurately reflect the function or structure of a relay. Thus, the rectangle with contacts is the most appropriate representation in this context.