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Sep. 2nd, 2009
Wireless electricity
Sep. 2nd, 2009 10:31 amA while ago I blogged about some old research into a self-charging battery, using the energy of wireless signals; the technology was never adopted for larger devices, presumably because there isn't sufficient energy in wireless transmissions to charge (say) a laptop battery. However, this technology is being considered for small devices (like alarm sensors) in the home - essentially doing away with the need for a battery.
Now there is an emergence of capacitive and electro-magnetic transmission techniques. The idea is that you'd put your laptop, iPod, or other device on a special mat. The mat generates a field which is then used by the device to recharge it's internal battery. And some companies are developing techology to 'broadcast' electricity within the home, so lamps would need to be near a transmitter, but would not require a cord or connection to a socket.
So true wireless transmission can be used over long distances, but provides very little power; and conduction devices can create large amounts of power, but require a 'transmitter' of some kind to be close to the device being powered.
Now a team at MIT have an idea to combine both approaches, using magnetically coupled resonance. This transmits not a radio wave, but a magnetic field tuned to a specific frequency that can be recognized by the device needing power. Multiple devices in a room would receive power from a single transmitter; they wouldn't need to be in direct contact with the transmission device.
No-one has yet evaluated the health risks associated with transmitting high levels of power using a magnetic field; hopefully they'll do some biological studies before introducing this in consumer products!
Now there is an emergence of capacitive and electro-magnetic transmission techniques. The idea is that you'd put your laptop, iPod, or other device on a special mat. The mat generates a field which is then used by the device to recharge it's internal battery. And some companies are developing techology to 'broadcast' electricity within the home, so lamps would need to be near a transmitter, but would not require a cord or connection to a socket.
So true wireless transmission can be used over long distances, but provides very little power; and conduction devices can create large amounts of power, but require a 'transmitter' of some kind to be close to the device being powered.
Now a team at MIT have an idea to combine both approaches, using magnetically coupled resonance. This transmits not a radio wave, but a magnetic field tuned to a specific frequency that can be recognized by the device needing power. Multiple devices in a room would receive power from a single transmitter; they wouldn't need to be in direct contact with the transmission device.
No-one has yet evaluated the health risks associated with transmitting high levels of power using a magnetic field; hopefully they'll do some biological studies before introducing this in consumer products!
Blogs I am reading...
Sep. 2nd, 2009 12:04 pmA British comedian, Dave Goreman, has started a cycle ride to the four corners of Britain. For those who are geographically challenged, I should point out that Britain isn't actually square. It looks more like the bit of the 1000 piece jigsaw that turns out to be missing from the box. Anyway, what he's really doing is cycling to the x-most points in Britain - Southern-most, Eastern-most etc. He started from the Southern-most point - Lizard Point in Cornwall. The trip will take him through 1500 miles of UK countryside.
His blog of the trip is here: http://gormano.blogspot.com/
His blog of the trip is here: http://gormano.blogspot.com/