Human Powered Devices

Some human powered things

Pictured is a collection of human powered devices. A push along lawnmower, a bicycle (with dynamo front light), a wind-up alarm clock, a wind up pocket watch, a wind up radio and a wind up torch.

In the alarm clock and the pocket watch energy is stored in a spring which, as it unwinds, powers the mechanism.
In the wind up radio energy is also stored in a spring which then drives a dynamo to power the radio.
In the wind up torch energy is stored in a rechargable battery which is charged by a dynamo when the handle is turned.

Usefulness = (Functionality x Availability) – Burden