Smoke alarm detectors

Is a simple fire alarm circuit based on detection of fire LDR and lamp of a few. Uses a very simple detect smoke in the air approach. Works produced by the smoke during fire.The remote sensing circuit alarm produces an audible alarm if fire exits with smoke.

This is not an ideal approach probably because the brightness of false alarms, the cause intéressante.Juste atmosphere but experience includes all the lights, in the experimentieren.Und please count on you as a substitute for a real alarm fire - device.

If there is smoke-free on LDR LDR.The resistance bulb low fall and ECA therein (see lamp) .the therefore transistors and nothing makes geschieht.Wenn thing enough smoke, light falling on LDR to conceal the RDA increases resistance and do voltage through it.Now transistor is to be moved ON.This empowered the IC1 and will strengthen gives 5V.This powers of IC (IC2) to play music by Music.this UM66 generator by IC3 (TDA 2002) drive speakers.

D1 and D2 diode in combination fall 1.4 V nominal voltage (Fujifilm) UM66 .um 66 type can support more than 4V.

Customize note:

• The speaker can be a speaker for acute 8th.
• R4 POT can be used to adjust the sensitivity of the alarm.
• TOPS R3 can be used for a different from the alarm volume.
• (General purpose NPN transistor BC548 BC148, 2N222) can be used for the first quarter.
• The circuit can be provided on a 9 v battery or a DC power supply 9.
• To enjoy a brilliant with a resistance of 1 k series to use LED bulb.

Source: smoke alarm detectors

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