Alarm system

An automatic fire alarm system is designed to detect the unwanted presence of fire by monitoring environmental changes associated with combustion. In general, a fire alarm system is classified as either automatically actuated, manually actuated, or both. Automatic fire alarm systems can be used to notify people to evacuate in the event of a fire or other emergency, to summon emergency services, and to prepare the structure and associated systems to control the spread of fire and smoke. 

Fundamental configuration:

• Fire alarm control panel: This component, the hub of the system, monitors inputs and system integrity, controls outputs and relays information.
• Primary Power supply: Commonly the non-switched 120 or 240 Volt Alternating Current source supplied from a commercial power utility.
• Secondary (backup) Power supplies: This component, commonly consisting of sealed lead-acid storage batteries or other emergency sources including generators.
• Initiating Devices: This component acts as an input to the fire alarm control unit and are either manually or automatically actuated.
• Notification appliances: This component uses energy supplied from the fire alarm system or other stored energy source usually to evacuate. This is done by means of a flashing light, strobe light, electromechanical horn, speaker, or a combination of these devices.