A broken CD or DVD or other type of optical disc is a serious problem and one that will likely lead to loss of information stored on this media. A broken optical disc refers to a disc that has split into two or more pieces or perhaps a disc simply missing one piece.
A motion detector is a device that detects moving objects, particularly people. A motion detector is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area.
Many of us are familiar with motion sensors, as they have become a common part of most home security systems. These sensors are much like the motion detectors that open the doors to the grocery store or cause the sinks and toilets in the airport to activate without touch. We see motion-sensing devices everywhere. But how do they work? There are two basic types of motion detecting systems. There are those with active sensors and those with passive sensors. Active sensors send out ultrasonic sound waves and passive sensors detect infrared energy.