New Fire Alarm Circuit with TDA2002

New fire alarm circuit

This system prevents users from fire. It depends on the smoke, which consists of a fire.

When the smoke takes the bulb and LDR, the amount of light falling LDR decreases.

This causes the resistance LDR increases, and voltage transistor base pulled high which makes the provision of COB (chip on board) will be completed. Different ears available in the market to create different sounds.
COB select depends on the user. Signal generated by COB supplemented by audio amplifier.

Under this system, audio power amplifier is connected to some IC TDA 2002. Sensitivity of the system depends on the distance between the lamp and LDR, and create a pre-VR1. This may be a lamp and LDR at an appropriate distance, you can toggle between pre-VR1, to obtain optimal sensitivity.
ON / OFF switch is proposed to contain the system or outside.