What does a square with a darkened upper triangle represent?

A square with a darkened upper triangle typically denotes a DC relay in electrical schematics. This graphical representation is standardized in many electrical diagrams to provide clarity on the device's function and power source.

In a position to differentiate devices on a schematic, other symbols may represent components like AC relays, timers, or latching devices. For instance, an AC relay would usually have distinct characteristics that differentiate it visually from a DC relay, such as a different symbol or marking to indicate it operates on alternating current. A timer and latching device also possess unique symbols that indicate their specific functions, which do not resemble the darkened upper triangle of a DC relay.

Understanding these symbols is crucial in electrical engineering and mechanics; they help identify the type of relay and its operational parameters quickly. Hence, recognizing a darkened upper triangle specifically as a signal for a DC relay enhances one's ability to interpret and work with electrical diagrams efficiently.