Laser Trip Wire Security System | Simple DIY Project

How to make a simple laser security alarm system, step by step video. You can see the circuit of this project at 00:54
What components you will need:
1. two MOSFET transistors 2N7000
2. an active 12V buzzer (or 5V active buzzer)
3. a light dependent resistor LDR07
4. a button.
5. an LED.
6. 1K Ohms resistor.
7. 470 Ohms resistor.
8. wires.
9. a 5V DC power supply.

Although I use a 12V active buzzer, it works perfectly with 5V as well.
You can use a 5V active buzzer without any problems, it would be even better.

IMPORTANT: Don't use a power supply with higher than 5V output !!!

If you have any questions ask in the comments below.

[anthonydonnelly]

Very Interesting. Might use this. Thanks

[militarypowerbestcountrys]

It is really amazing I love that sir. I wanna ask you some thing si ok with that

[MDJahangirAlam-pdwo]

its good...but i need dc 12or 24v even ac 220 v

[iamarendra]

I did it but its not working and the reset button is not working

[FredBombardier]

Really good project. If I don't want to turn off laser pointer with the reset button but only want to turn the buzzer off (and LED) with reset button, can I just solder the reset button else where in the circuit? I think maybe on both sides of the buzzer so the LED and buzzer will be off with the reset. Maybe it's more complicated but your help will be appreciated

[keithwatkins]

I tried this but when I test with the laser beam on to the LDR it works when you break the beam your one switches the laser off my one stays on it does not break the circuit could it be my switch I think yours is a press button please advise me

[joemata]

I also am having trouble the indicator light stays on also the lazer but nothing happens when 8 break the light connection to the sensor . Any ideas??

[sampatchoudhary]

it worked really well for the first time but now the buzzer and led stays on when i point the laser on ldr and release the button please help

[sophiadavis]

do you sell these online?. it would be easier for me to buy this from you..

[mikelee]

The burglar will trip over the wires and become tangled up in the wires. Needs to be wireless in real world application

[MainIrishAnglingTv]

Great video, but can I run the laser and the circuit from different power supplies, I want to put the laser on the other side of a room, thank you

[Rahulroy-zucg]

sir, i had made this project and it is working great .But, can you give me a circuit diagram other than (00:54) in google or give me a ppt based on this project if you can, it will help me a lot .

hello, how your " light dependent resistor LDR07" work? is it out put analog signal ?
i build something like your but it dont work! i think my problem is the light resistor.

[rippalmer]

Can you use a BC557 or BC547 instead of 2N7000?

[trulyprescilla]

would it be fine if I replaced the 2N7000 with a different transistor? if so which one should I use considering that I used all the exact materials listed.

[AbdullahKhan-ymmd]

Sir please make this video again its to fast and explain it clearly

[YashPatil-sysk]

Please give me any idea or option to make the surface of ldr big and more sensitive. It takes too much time to adjust the laser on the ldr.

[jaivarma]

Hey man great video but my model seems to be having a problem. I have done everything accordong to the circuit except that since i couldnt find 2n7000 mosfet i used an IRFZ44N mosfet . From a previous comment i modified the circuit by adding a 51k resistor parallel to the LDR and added a 2.7 k ohm instead of the 1 k ohm resisitor. But the laser does not stay on but turns off when i stop pressing the button and after that the buzzer and light turn on on themselves . Please help me if you can . Thank you

[nimalyughan]

Does the circuit components get damaged if 9v battery is used??

[don-alpatchino]

Sir, I tried your method, but when I turn the laser another time the buzzer turn off. where is the problem ?