Introduction: Lazer Security Alarm

Picture of Lazer Security Alarm

this is a lazer security device that'll alarm u when something comes in the contact of the lazer beam and will be very helpfull

Step 1: Materials and Tools

Picture of Materials and Tools

shouldering iron
shoulder wire
resistors 100ohms×2
transistors bc548 ×2
lazer diode
3v battery pack

Step 2: The Circit and Wiring

Picture of The Circit and Wiring

The above given circit is of the reciver the lazer beam will touch the ldr and if something will block the path of lazer beam the ldr will complete the circit thus activate the buzzer and led

Step 3: A Rough Demo

Picture of A Rough Demo

this is a rough demo of the wiring to be done on pcb

Step 4: The Final Asssembly

Picture of The Final Asssembly

in the final assembly choose a dark place to do it and pogition the laser to the ldr. u may add a relay to the circit and connect it to an appliance lice ur room light as u enter the room lights and fans would. turn on on thier own


shadowamit (author)2015-05-17

hay help me in wiring of second transistor base where to connect i connected wid led but nothing happen

p mishra (author)2014-06-26

and guys plz vote for me in contests

marcoboers (author)2014-06-26

In your wiring diagram the base of the second transistor, in series with led, isn't shown connected ;)

p mishra (author)marcoboers2014-06-26

hey thats not a problem yuo can correct it

p mishra (author)2014-06-25

hey guys plz comment on me so I could upload even more inventions

kag432 (author)p mishra2014-06-25

How hard was it to get the laser lined up? Most I've seen in the past just use infrared so it doesn't have to be exact. Also, how much did this end up costing?

p mishra (author)kag4322014-06-25

was easy just keep ur camera on and youll see where the lazer is

About This Instructable




Bio: I am 14 year old and a passionate technology enthusiast i want build my career as a software developer i love electronics,programming,android os ... More »
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