DWELLING UNIT FIRE ALARMING DEVICE

• Main Author: ISHIKAWA KATSUKI
• Format: Patent
• Language: English
• Published: 05.08.1997
• Edition: 6
• Subjects: ALARM SYSTEMS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; ORDER TELEGRAPHS; PHYSICS; SIGNALLING; SIGNALLING OR CALLING SYSTEMS; TELEPHONIC COMMUNICATION

PROBLEM TO BE SOLVED: To surely issue a fire alarm, regardless of the ratio of a current in case of fire and the current in monitoring. SOLUTION: The device is provided with a receiver EQ1 connected through two wires L1 and L2 to fire sensors SE1 and SE2 and the receiver is provided with an interface IF1 capable of detecting the current i1 in case of disconnection, the current i2 in monitoring and the current i3 in case of fire, an audio equipment SP1 and an alarm display lamp LED1 for flickering alarm display. Then, for the interface, detection parts K1 and K2 composed of transistors Q1 and Q2 , Schottky diodes D1 and D2 connected between the base and collector of the transistor, base resistor R1 and R2 connected between the base and emitter of the transistor are cascade-connected in plural stages, the two wires are connected to the detection part of a first stage and detection signals f1 and f2 are taken out from the detection parts of the respective stages.