This smoke detector is designed using 555 timer circuit and some common electronic components. The photo interrupter module is used as the smoke detector, while timer 555 is wired in astable configuration as an AF oscillator for sounding alarm via a loudspeaker.
This 555timer clap switch circuit electronic project is designed using some common electronic parts . This 555 timer clap switch circuit electronic project operates from a distance of up to 10 meters from the microphone . Signal from microphone is amplified by transistors T1, T2 and T3. Diode D1 detects clap signals and the resulting positive voltage is applied to the base of the transistor T4 .
This door open alarm electronic project is designed using an linear hall effect device and a 555 timer circuit. This door open alarm alarm electronic project is based on the TL3103 linear hall effect device used for detecting the angle of rotation. The TL3103s are centered in the gap of a U-shaped permanent magnet.