Product Description

Most smoke detecting circuits available commercially, make use of expensive smoke sensors which require complicated interfacing circuitry around them. However, the Smoke Alarm implemented here is capable of detecting smoke consistently and employs a simple phototransistor optical interrupter switch as the smoke sensor. This smoke-detecting circuit utilizes the simple fact that in case smoke is present, the optical signal transmitted from the infrared emitting diode to the photo-transistor (both part of the photo interrupter module) will be interrupted. Once such a situation is encountered, an alarm sound is generated by the loudspeaker till the time smoke clears. Number of ICs used: 1.