Excerpts from an February 8, 1996 article in the New York Times, titled A Crank- Up Radio Helps Africa Tune In describes the popularity of crank-up electronic devices being sold in 3rd world countries and even in Japan. BayGen Power, located in South Africa, manufacture the devices which to date in clude radios and flashlights.
For about six weeks now, a small factory in [Milnerton, South Africa], just north of Cape Town has been cranking out radios with cranks. Give the handle a few aerobic turns and the Freeplay radio holds forth for half an hour. ... It weighs six pounds, it's built like an overstuffed lunch box, and it has a tinny speaker. But its wholesale price is only $40 and it gets AM, FM and shortwave.
The technology can save poor people a fortune. In a radio played 5 to 10 hours a day, a Freeplay will save $500 to $1,000 in battery costs over its three-year lifespan, said Siyanga Maluma, who runs the marketing operation. There is a market out there. "Ghana wants 30,000," said Christopher Staines, an executive of BayGen Power, the manufacturer. ... "And can you believe it?" Mr. Maluma said. "We've just shipped some to Japan." Their next product, due out next year, is a wind-up flashlight.
The patent is the work of Trevor Bayliss, a British scientist who in 1990 was listening to a BBC program on AIDS in Africa that mentioned the difficulty of sending the safe-sex message because many villages could not afford batteries. He went to his workship, built a prototype, and then could not market it. "For two years," Mr. Staines said, "the big companies like Philips and Marconi said, 'That's all very nice, Trevor, but who needs it? And besides, you're a bit of a crank yourself.' Then Trevor persuaded the BBC to do a story about him."
There are actually 13 patents covering the mainspring and gears that drive a little dynamo. The spring does not in any way resemble a Swiss watch's. Unwound, it is 30 feet long and designed for rewinding auto seat belts. A double-spool mechanism keeps its tension constant.