Fire alarm circuit
Description.
Here is a simple fire alarm circuit based on a LDR and lamp pair for sensing the fire.The alarm works by sensing the smoke produced during fire.The circuit produces an audible alarm when the fire breaks out with smoke.
When there is no smoke the light from the bulb will be directly falling on the LDR.The LDR resistance will be low and so the voltage across it (below .6V).The transistor will be OFF and nothing happens.When there is sufficient smoke to mask the light from falling on LDR, the LDR resistance increases and so do the voltage across it.Now the transistor will switch to ON.This gives power to the IC1 and it outputs 5V.This powers the tone generator IC UM66 (IC2) to play a music.This music will be amplified by IC3 (TDA 2002) to drive the speaker.
The diode D1 and D2 in combination drops 1.4 V to give the rated voltage (3.5V ) to UM66 .UM 66 cannot withstand more than 4V.
Circuit diagram with Parts list.
Notes.
- The speaker can be a 8Ω tweeter.
- POT R4 can be used to adjust the sensitivity of the alarm.
- POT R3 can be used for varying the volume of the alarm.
- Any general purpose NPN transistor(like BC548,BC148,2N222) can be used for Q1.
- The circuit can be powered from a 9V battery or a 9V DC power supply.
- Instead of bulb you can use a bright LED with a 1K resistor series to it.
is there any new upgraded circiut on fire alarm circuit
Hello I am an Electrcal /Electronics Eengineering Student, Ineed some Projets espeially Automatics, sensing & control circuits please. P.O.Box 7136 Bompai, Kano Nigeria.
i am an electrical/electronic student,and i am very good at reading circuit and constuction,please i want you to send the fire alarm circuit and its working principle,so i can construct one.thanks.hoping to recieve it in my mail provided to you.
Any replace ment for UM66 and TDA2002?
hi there! i want 2 build a magnetically levitation train. can u send me more details about the construction. i want 2 use solenoid and permanent bar magnets. hoping 2 recieve it in my mail provided 2 u. thanx
i am an electrical/electronic student,and i am very good at reading circuit and constuction,please i want you to send the fire alarm circuit that made by micro .
what should be the value of the ldr?? or its range??
any general purpose LDR will do
Nice easy fire alarm circuit and its operation is simple.I like the circuit and expect i do it.
Plz i want to build a 2000Watts inverter pls send me the circuit diagram and the rating of the components required to my email address.which is geracotin2000@yahoo.co.uk. thanks.
i am working on it
Can we use a resistor insted of pot?
thanks sir i want’s that it’s my requared for my project.
Sagar
Yes you can if you so desired. It would be a bit pointless though as the purpose of using a pot and not resistor is so that you can adjust the signal.
Dear Sir/Madam
I am an electronic student and i would like you to send me some information on how to design a smoke alarm sensor.
Very Important ( Please do not publish my email)
Thanks
Kev
can u please provide me with the circuit diag. of the detector which includes diff another alarms along with the fire alarm….plz mail me…
[...] Source: Smoke Detector for Fire Alarm [...]
Dear Sir/Madam
I am an electronic student and i would like you to send me some information on how to design a smoke alarm sensor.
Very Important ( Please do not publish my email)
Thanks
hi, am a student and i want to do this project so plz i want all the details about this project
thants
sir/ madam,
I would like to know abt the names & authors of any text book that contains all electric/electronic circuit concepts.
V.Chandran
hey i implement this circuit today but i was failed to do it properly..!there was a little beep in the beggning but then it stopped.can any body send me schematic diagram of this Circuit?
You need to calibrate this circuit before using. Adjust the POT and try again.
hi,i m verry happy for your support provided ,so ,i’ll like to get all notes concerning fire alarm circuit ,in oder to improve my reseach .thank u