Additional function-expandable fire detector

An additional function-expandable fire detector, comprising:

• a body (100);
• a contactless output circuit unit (200) that is installed in the body (100), that directly detects a fire, and that outputs an optical signal to an outside;
• and
• a stand-alone module (300) that is coupled to the body (100), that detects the optical signal of the contactless output circuit unit (200), and that provides notification of the fire;
• wherein the contactless output circuit unit (200) comprises:
• a power input unit (210) that receives power;
• a sensor unit (220) that detects a fire phenomenon by using the power of the power input unit (210);
• an operation monitoring unit (230) that monitors input power of the power input unit (210) and breakdown of the sensor unit (220);
• a fire determination unit (240) that determines whether a fire occurs by using a measured value of the sensor unit (220);
• a preliminary fire determination unit (250) that determines an occurrence of a preliminary fire by using the measured value of the sensor unit (220);
• a switching unit (260) that issues a fire alarm by short-circuiting the input power in response to a fire signal of the fire determination unit (240);
• an operating state LED unit (270) that outputs a first optical signal to the outside via a signal of the operation monitoring unit (230);
• an alarm issuance LED unit (280) that outputs a second optical signal to the outside according to an operation of the switching unit (260);
• and
• a preliminary alarm LED unit (290) that outputs a third optical signal to the outside via a signal of the preliminary fire determination unit (250).