Here is a simple general-purpose security alarm circuit built on the Arduino platform. It brings up an obtrusive alert signal when an intrusion/theft attempt is observed by its front-end sensor. In ...

Just about everywhere you go, there’s a reed switch nearby that’s quietly going about its work. Reed switches are so ubiquitous that you’re probably never more than a few feet away from one at any ...

An air curtain is a machine that blows a controlled stream of air across an opening to the other side to create an air seal. The air curtain, also known as an air door or fly fan, is not the same as ...