字體：小 中 大 |
|
|
|
| 2017/11/09 16:43:58瀏覽192｜回應0｜推薦0 | |
| Power cables are a pain: ugly, inconvenient, always in a tangle, something to trip over and there are never enough sockets to plug them into. So imagine how convenient it would be if cat6 cables could be replaced by beamed power. This is not a dream; in fact a world without power cables might be just around the corner. For many years engineers have sought to replace power cables with beamed energy, though until recently the complications have been too difficult to crack; now recent breakthroughs have put these objectives back on track. Currently this is receiving some real backing from the likes of Intel and Sony, already there are televisions, mobile phones and laptops computers that can be powered without wires. Wireless power transmission is not new. In 1901 Tesla Tower was erected to do precisely that however the project was halted due to lack of sufficient funds. That was the end of the notion until, in the 1960s, it was shown that model aircraft could be powered by beaming microwaves at them. In the modern era, the reason for the resurgence of interest in power without cables is that data communications implemented using Bluetooth and WiFi have highlighted how convenient it would be if the 1/0 welding cables could also be replaced by wireless. Currently there are three ways to transmit power wirelessly. These are using radio waves, using lasers, and using magnetic induction. We will look at all three of them. Radio Waves: This technology builds on the same kind of technologies used in Bluetooth and WiFi to transmit power. One company has already demonstrated that this technology is capable of transmitting milliwatts of power over distances of 15 meters. They are now working on versions of this that can be used for recharging portable devices such as mobile phones and laptops. Lasers: Here infra red laser beams are beamed at photocells that convert the light into electrical energy. This has been used to power such items as loud speakers and lamps. At present the system car cables for battery is not very efficient, but work is underway to improve the current efficiency of around 15% to around 50% which would make it suitable for powering such items as laptops. There is very little falloff of laser power over distance, so considerable distances could separate the laser from what it was charging. Special devices could be used to cause the beam to track the device when it was moved and thus keep the beam focussed, though line of sight must be maintained. Magnetic Induction: Whilst the first two technologies are suitable for devices that use low amounts of power, magnetic induction can be used to transmit large amounts of power. This technology creates a magnetic field by passing a current through a coil. This magnetic field then induces a current in another coil placed in it. Although low power versions of this are commonplace (for instance electric shavers) the energy source and device have to be very close together as the efficiency reduces quickly with distance, though this can be improved by using tuned circuits, a technique known as resonant transfer. Using this it is possible to power a television half a meter away from the power 4 gauge battery wire source with a loss of only 30% of the transmitted energy. Sony has already demonstrated an entirely wireless powered television and Intel is also applying the technology to various consumer items. Last Word There remain a number of challenges before this technology becomes commonplace, including a number of health and safety issues. The implications of high power energy beams are not fully understood and it is possible that there are long term effects of being exposed to high energy magnetic fields; certainly there are potential dangers for people fitted with pacemakers. With so much emphasis on improving the efficiencies of electrical and electronic equipment, a technology that reduces efficiency would be likely to meet serious objections. However, these technologies are still under development and it is probable that the challenges will be met and the concerns diffused. http://www.centralplaincable.com/html/en/products/weldingcable/363.html |
|
| ( 創作｜散文 ) |
