What type of circuit energizes signaling equipment?

The type of circuit that energizes signaling equipment is a signal circuit. Signal circuits are specifically designed to transmit information, typically in the form of signals, to operate signaling devices such as lights, bells, or alarms. This aligns with the primary function of a signal circuit, which is to convey information rather than to provide power or control functions.

In contrast, power circuits are used to supply electrical energy to devices for their operation, which is not the focus of signaling equipment. Control circuits are often involved in the operation of devices by regulating their functions or operations but do not primarily carry out the signaling aspect. Alarm circuits are more focused on warning systems, and while they might utilize signals, their primary purpose is to indicate a hazard or alert users to a condition that requires attention.

Therefore, the definition and purpose of a signal circuit directly correspond with the function of energizing signaling equipment, making it the most accurate choice in this context.