Touch the sensor of the alarm with your finger and it starts beeping, goes on for some time and then stops. Touching it again, and it goes again! This little and flexible circuit consists of a touch ...

This circuit uses a thin piezoelectric sensor to sense the vibrations generated by knocking on a surface; eg, a door or table. Basically, it amplifies and processes the signal from the sensor and ...

Ring's $199 Z-Wave-enabled Alarm Security Kit is so simple you might overlook it at first. The system includes a base station, a keypad, a door/window sensor, a motion sensor and a Z-Wave range ...