快猫短视频

IT SOUNDS like a step backwards, a return to the sepia-tinted days of the
Model T Ford and the crank-handle gramophone. But clockwork is making a
comeback. Everybody knows about wind-up radios and torches, but they鈥檙e just the
start. A wind-up charger for mobile phones should be on the market by the end of
the year. If that takes off you could soon be cranking your Discman, MP3 player,
pager, laptop computer鈥攐r any other battery-powered device you care to
mention.

Wind-up electricity has obvious advantages. It鈥檚 free, if you don鈥檛 count the
cost of the energy your arm burns as it cranks the handle. And it鈥檚 always
there. You鈥檒l never need to buy another battery or curse yourself for forgetting
to charge up your phone or laptop. More importantly, wind-up electronics has the
power to transform lives. Two billion people in the developing world have no
mains electricity and cannot afford batteries. Wind-up power can give them
access to modern information technology. And according to the UN, that
technology helps banish poverty
(快猫短视频, 14 July, p 17).

The wind-up revolution began ten years ago when British inventor Trevor
Baylis saw a BBC television documentary about AIDS in rural Africa. He realised
that a radio that didn鈥檛 need mains electricity or batteries would help battle
the ignorance that hastened the spread of the disease. So off he went to tinker
in his shed. He emerged with a clockwork radio that played for 14 minutes after
30 seconds of winding. It was a beautifully simple, fail-safe idea. Turning the
hand crank coiled a thick steel spring from one spool to another. As the spring
slowly unwound, a system of gears drove a generator that produced electricity to
power the radio. All it took was a little elbow grease.

Baylis鈥檚 invention was aimed at Africa but it became a surprise hit in the
developed world. Despite being written off as a gimmick, wind-up radios acquired
a sort of 鈥渓o-fi鈥� cool. Freeplay Energy, the company that bought Baylis鈥檚 idea
and turned it into a commercial product, played up to the image by making the
cases out of transparent plastic so you could see the innards clunking around.
People found the radios useful for camping and gardening. They put them in their
bathrooms and sheds. Since 1996, Freeplay has sold more than a million wind-up
radios to Western consumers. European and Japanese electronics giants quickly
jumped on the bandwagon. Sony, Philips and Aiwa now sell wind-up radios.

Clockwork torches soon followed, and Freeplay started talking about other
wind-up gadgets, including CD players, mobile phones and laptop computers. But
they never emerged.

The problem is you only get out of a wind-up device what you put in. Crank
one of the radios for a minute or so and you鈥檙e rewarded with 30 minutes of
play. Well worth the effort, but bear in mind that radios don鈥檛 consume much power.
The more power-hungry the contraption, the less operating time you get for your effort.
A 1-minute wind on a torch gives you just 6 minutes of light鈥攁nd torches are
hardly energy guzzlers. Freeplay uses light-emitting diodes that consume just 24
milliwatts.

For anything much bigger, this makes wind-up technology impractical. An
average laptop, for example, consumes about 35 watts. For an hour鈥檚 computing
time you鈥檇 need to crank in at least 126,000 joules. That鈥檚 roughly equivalent
to 3 vigorous minutes on an exercise bike鈥攁ssuming an impossible 100 per
cent efficient energy conversion. And nobody wants a bicycle-powered computer.
Mobile phones consume about 2 watts when they鈥檙e beaming information to a base
station. Less demanding, but you鈥檒l still have to put in a lot of physical grind
for a decent conversation.

However, this problem is slowly going away. Manufacturers of mobile phones
and laptops, well aware that battery life is the biggest bugbear for consumers,
are making their devices ever more efficient. The target in computing is to
reduce power consumption by a factor of 10 (快猫短视频, 3 March, p
32). Once that happens your 3-minute workout drops to 20 seconds or so. In other
words, mainstream consumer electronics are entering the purview of wind-up
power.

By the end of this year you should be able to buy the first 鈥渘ext generation鈥�
wind-up product鈥攁 hand-cranked charger for mobile phones. Developed by
Freeplay and marketed by Motorola, the unit works with any mobile phone
currently on the market. Winding the palm-sized generator for 30 seconds gives
you 6 minutes of talk time or 2 hours on standby. Not a lot, but enough for
emergency back-up.

The phone charger鈥檚 wind-up mechanism has been upgraded to make it lighter,
smaller and more convenient than Baylis鈥檚 original spring-driven unit, which
stored energy in mechanical form and converted it to electricity on the fly. In
place of the steel spring the Motorola charger has a dynamo, a current converter
and a rechargeable lithium-ion battery. The dynamo converts your elbow grease
into an alternating current, the AC-to-DC converter turns that to direct
current, and this is stored in the battery for later use. That means you can
charge up at your convenience rather than just before you want to use it. Recent
models of the Freeplay radios and torches use a similar system, as do the Aiwa,
Sony and Philips radios.

The charger has some obvious drawbacks. You鈥檒l have to leave your mobile
plugged into the unit鈥攊t doesn鈥檛 charge the battery inside the phone. You
can鈥檛 crank very quickly because the lithium-ion battery only recharges at a
leisurely pace. The optimum input power is 8 to 10 watts, which is frustratingly
sedate. Freeplay says the chargers will retail for up to 拢45. That鈥檚 a lot
more than battery-powered emergency chargers, but with no outlay on batteries
they eventually pay for themselves.

Another British inventor is pushing wind-ups even harder. Howard Atkin, head
of Atkin Design and Development in Harrogate, North Yorkshire, has prototype
wind-up units designed to power anything from electric razors to laptops. His
systems also use a hand-cranked generator, but instead of a rechargeable battery
they have an energy storage device called a supercapacitor. Atkin claims his
set-up is more efficient than Freeplay鈥檚. To prove it he bought a radio from his
local shop and modified it to draw power from one of his packs. It played for 90
minutes on a 1-minute wind.

Battery beater

Supercapacitors鈥攁lso called ultracapacitors鈥攁re a cross between a
regular capacitor and a rechargeable battery. Like normal capacitors they store
electrical charge. But their capacity is a billion times higher. That鈥檚 because
the electrodes are made from carbon powder, giving them a huge surface area to
store charge.

One big plus for wind-up applications is that supercapacitors can absorb
large amounts of charge in seconds. That means you can crank away as vigorously
as you like. Supercapacitors can also be charged and discharged many more times
than a rechargeable battery. They cost about the same and they鈥檙e more
efficient, releasing 92 per cent of the energy you put in a compared with 85 per
cent for a nickel metal hydride battery. The downside is that supercapacitors
discharge quickly, so they are good for pulses of power but not a steady stream.
Atkin, however, is planning to use a new type that discharges gradually.

Just about any gadget that currently uses a battery can be wound up instead,
says Atkin. He aims to have radios and torches on the market by this time next
year. After that will come all sorts of devices with built-in crank handles:
mobile phones, personal stereos, pagers and GPS receivers.

So what about wind-up computers? In 1997, in front of the Conference of
Commonwealth Education Ministers in Botswana, Baylis attached one of his spring
generators to a small portable computer called the Apple Newton eMate 300. From
1 minute of winding he generated 14 minutes of computing power. The eMate has
since been phased out but it was designed for low power consumption, which
suggests a bright future. And the market is there: how many times has your
laptop battery fizzled out after two hours even though you charged it up all
night?

Once wind-up gadgets make it onto the market their success is in the hands of
consumers. But one day soon, people cranking furiously at their MP3 players
might be a common sight.

That鈥檚 all well and good for Western gadget-buyers. But what of Baylis鈥檚
vision for the developing world? At first glance it seems the next generation of
wind-ups have been designed exclusively with rich consumers in mind. Sony,
Philips and Aiwa don鈥檛 sell their radios in developing countries and have no
plans to do so. The Motorola phone charger will be launched in Europe and North
America. And Atkin鈥檚 target will be the kind of electrical boutique where he
bought his prototype radio, not the street vendors of downtown Lagos.

It would be a tragedy if the wind-up revolution bypassed the developing
world. 鈥淥ne of the greatest barriers to alleviation of poverty is information,鈥�
says Kristine Pearson, executive director of the Freeplay Foundation, a
development trust founded by Freeplay in 1998. 鈥淏ut the biggest limitation is
power; it鈥檚 about a regular electricity supply.鈥�

Kate Raworth, co-author of this year鈥檚 UN Human Development Report, agrees.
She says the principal need is for wireless communications such as mobile
phones. 鈥淎ccess to communications can have far-reaching effects on people鈥檚
lives,鈥� she says. 鈥淎nd wind-up technology offers the possibility of moving
forward without having to supply electricity to rural areas.鈥�

To get some idea of the technology鈥檚 potential, consider what the original
Freeplay radio has done for rural Africa. In 1997, the African Centre of
Meteorological Applications for Development began broadcasting weather forecasts
to farmers in its native Niger. With the help of Freeplay radios it now reaches
49 countries. And after last year鈥檚 floods the Freeplay Foundation distributed
more than 7000 radios to destitute people in Mozambique. A daily programme
called Ndhambi broadcast information on health, hygiene, sanitation, locating
land mines and contacting lost family members.

Mobile phones also change lives, as the 鈥渧illage phone鈥� initiative in
Bangladesh has shown. Members of the Grameen Bank, which operates a bit like a
credit union, can take out loans to rent a mobile, which then becomes the
payphone for their village. When villagers use the phone, they pay the operator,
who can then pay back the loan and start making a profit. Muhammad Yunus,
managing director of Grameen, says that the scheme is having a real impact on
poverty. People use the phone to buy and sell goods and keep track of market
prices. And the villagers can keep in touch with relatives working in the Gulf
and Singapore.

But electricity is a problem. Many of the 30,000 subscribers in rural
Bangladesh are in the paradoxical situation of having network coverage but no
mains electricity. The situation worsens the further you move out from Dhaka.
It鈥檚 a common problem all over the developing world. At the moment, Yunus says,
villagers use solar panels to power the phone batteries, but these are
expensive, intermittent and fragile. Imagine the impact a wind-up charger would
have.

Yet Grameen has no plans to use wind-up electronics. And how could it, when
the charger costs 拢45? 鈥淚t is too expensive for a true developing country
market, we know that,鈥� admits John Hutchinson, Freeplay鈥檚 technical director. He
says the company is working on a cheap alternative, although it will take time
to get the price down and the distribution network in place. The main problem is
the cost of the components. Rechargeable lithium-ion batteries are expensive,
and the 鈥渉andshake鈥� between the phone and the charger鈥攖he signals they
send to recognise one another so they can exchange information鈥攔equires
sophisticated microelectronics. Freeplay engineers are trying to halve the cost
by cutting corners in the generator. 鈥淚n the developing market, you鈥檙e not
trying to sell it on efficiency,鈥� says Hutchinson. 鈥淧eople are prepared to put
in more effort.鈥�

Ultimately, the aid and donor communities want to get computers with Internet
access into the developing world. 鈥淥ur big turn-on, eventually, is that the
third or fourth generation of the Internet will be wireless. That鈥檚 where we
want to be,鈥� says Hutchinson. And he says the best way to power those computers
is with wind-up generators. 鈥淚 don鈥檛 know how to do it yet, but I think it鈥檚 the
next thing.鈥�

The real problem is that there is no money to be made in developing
countries, and hence no market for wind-up electronics. In Africa, Freeplay
radios sell for 拢26 to 拢36, depending on the model and the size of
the order. This is about half the retail price in Europe, but still beyond the
means of poverty-stricken people. Freeplay has sold 170,000 radios in developing
countries, but almost all have been paid for by aid organisations or government
grants.

Freeplay thinks the phone charger will be distributed by mobile phone
companies, whose expansion plans are frustrated by the lack of mains electricity
in parts of the developing world. But perhaps the best hope is that the new
generation of wind-up devices catch on in Europe and North America. After all,
without those million or so customers in the developed world, Freeplay would not
have been able to improve its technology or distribute radios to needy people in
Africa. The same scenario could play out with the newer technologies. So if you
want a wind-up revolution, go and buy the first wind-up device you see. The
gadget will pay for itself anyway, and you could be helping make life in the
developing world run more smoothly than clockwork.