All this talk about 555 timers is causing projects to pop out of the woodwork like this one that reverse engineers a shopping cart security mechanism. The wheel seen above listens for a ...

At Radford Racing School, these special casters are like training wheels for mastering car control. When crossing the gates ...

Shopping carts are surprisingly expensive ... If you left the track, a rod passing through the wheel locked it. A third magnet would disarm the brake when you entered the store again.