Laser Light Security Alarm | Full DIY Electronics Project
EFY's Electronics Design Community - CIRCUIT: Intruder Detector Using Laser Torch http://electronicsforu.com/electronicsforu/circuitarchives/view_article.asp?sno=1258&article_type=1&id=1082&tt=unhot&b_type=new#.VBaCkWNIg2w Here is a simple, low-cost ...