The idea of storing energy from a spring in an intermediate electrical form was taken a stage further in Freeplay's clockwork torch.

ECONOMIST: MONITOR

This basic idea of storing energy from the spring in an intermediate electrical form was taken a stage further in Freeplay's clockwork torch, which was launched last year.

ECONOMIST: Clockwork technology

The spring is wound for half a minute, and then unwinds over six minutes, charging a battery in the process, and providing enough energy to run the radio for an hour. (This means the radio's spring-controller circuit is no longer necessary.) Thus, Freeplay has switched from making solely spring-powered devices to making battery-powered devices that are equipped with a clockwork mechanism for recharging and emergency use.

ECONOMIST: Clockwork technology