This timer was designed mainly to switch off a portable radio after some time: in this way, one can fall asleep on the sand or on a hammock, resting assured that the receiver will switch off ...

This timer was designed for people wanting to get tanned but at the same time wishing to avoid an excessive exposure to sunlight. A Rotary Switch sets the timer according to six classified Photo-types ...

Electronic devices are built from many different parts. Understanding how these components work together is key to understanding electronics. Circuit diagrams use symbols to represent each component, ...