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IR burglar

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*Maha*

New Member
hi every body

i'm a new member here

"IR Burglar alarm " is my new project and this is its circuit

9037-567377028.jpg



please someone tell me how to work every IC in this circiut. please describe this circuit for me .


thanx :)

 

kpatz

New Member
The 555 in the transmitter section generates pulses that cause the IR LED to "flash" at a certain frequency.

In the receiver section, the IR receiver picks up these pulses. The 4538 is a monostable, meaning it goes high for a period of time when it receives an input signal, then goes low when the signal is absent for that amount of time.

So, when the beam is unbroken, the pulses keep the 4538 "on", which disables the siren circuit (the 3561). When a "burglar" breaks the beam, the 4538 will stop receiving pulses, and time out, enabling the siren.

When the beam is unbroken again, the siren will stop.
 
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