HI! Welcome to electrical projects channel In this video I’ll make simple ” Tripwire ” security alarm system using a transistor. For this device I use IRF540N MOSFET, but you can use different transistor Also we’ll need 47 kilo ohm resistor and active buzzer Here is the schematic: so let’s build this device Now we can connect this device to power source and check it. Device works ok. Now you can pull thin cupper wire and connect to this device and guard your territory If someone tears the wire you will know it You can connect even 1000 meters of cupper wire and this device should work ok This device has very low power consumption, so you can use a buttery for powering this device. If you don’t have a buzzer you can make your own sound indication device using a loudspeaker. Video you can find here: (link) Also you can use a relay instead of transistor, video you can watch here: (link) Thanks for watching!