Trevor Baylis wanted to make a radio that ran without mains electricity or batteries.
In his workshop at home - the classic inventor's den - he set about experimenting. Armed with the knowledge that a current is produced if you turn an electric motor by hand, Trevor tried coupling a hand-drill to a motor and connecting the wires to a small radio. When he turned the handle for the drill, the radio worked!
But having to stand and turn the handle to make the radio play was tiring and time-consuming. Trevor realised that he needed to find a way to store the energy and tried adding a clockwork mechanism. In his new clockwork machine, the handle wound up a spring. As the spring unwound, it released energy to power the radio.
The first working prototype ran for 14 minutes after 2 minutes of winding. Trevor Baylis had invented the clockwork radio.