Little Laser Trip Wire circuit ... beam sender circuit and the laser beam receiver circuit. The receiver circuit includes an electromagnetic relay to assist the switching process of external electric ...

[Gordon] sent us a tip about this simple laser trip wire system ... such as a system to disarm the trip wire, and a robust light detection circuit. This time around there’s more happening ...

This door alarm is based on the interruption of Laser beam. A low cost Laser pointer is used ... Dog repellent The electronic dog repellent circuit diagram below is a high output ultrasonic ...

As a preview of his latest book, Arduino Project Handbook: 25 Practical Projects to Get You Started, Mark Geddes takes us through the project to create a simple laser trip wire alarm. You've probably ...