The clockwork radio

27th February 1998 at 00:00
Take a strip of spring steel, wind it tightly into a coil and it will try to unwind. Harness the unwinding force, by connecting the spring to rotating gears, and you have a "spring engine''. The alternative name is "clockwork motor'' because this is how many clocks were driven before electricity came along.

However, a radio needs electricity, and so cannot be driven directly by clockwork. Trevor Baylis used a spring engine to drive a tiny electrical generator, the whole power pack being built into an ordinary sized portable radio. This is why the Baylis radio needs no batteries nor any outside power source, and is what makes it attractive in places like rural Ghana, where a few hours worth of batteries costs pound;10, an amount which is beyond most families.

A development project or agency can put Freeplay radios into a village for about pound;30 each.

Log-in as an existing print or digital subscriber

Forgotten your subscriber ID?


To access this content and the full TES archive, subscribe now.

View subscriber offers


Get TES online and delivered to your door – for less than the price of a coffee

Save 33% off the cover price with this great subscription offer. Every copy delivered to your door by first-class post, plus full access to TES online and the TES app for just £1.90 per week.
Subscribers also enjoy a range of fantastic offers and benefits worth over £270:

  • Discounts off TES Institute courses
  • Access over 200,000 articles in the TES online archive
  • Free Tastecard membership worth £79.99
  • Discounts with Zipcar,, Virgin Wines and other partners
Order your low-cost subscription today