MYCHARGEMAN Forum

mustahil lg rsnye buat ms skrg ni...sy pun x pnh dgr atau tgok...

Saya kelihatan lebih berminat tentang ini:

 

Microwave method

Power transmission via radio waves can be made more directional, allowing longer distance power beaming, with shorter wavelengths of electromagnetic radiation, typically in the microwave range. A rectenna may be used to convert the microwave energy back into electricity. Rectenna conversion efficiencies exceeding 95% have been realized. Power beaming using microwaves has been proposed for the transmission of energy from orbiting solar power satellites to Earth and the beaming of power to spacecraft leaving orbit has been considered.^[2][31]

Power beaming by microwaves has the difficulty that for most space applications the required aperture sizes are very large due to diffraction limiting antenna directionality. For example, the 1978 NASA Study of solar power satellites required a 1-km diameter transmitting antenna, and a 10 km diameter receiving rectenna, for a microwave beam at 2.45 GHz^{[citation needed]}. These sizes can be somewhat decreased by using shorter wavelengths, although short wavelengths may have difficulties with atmospheric absorption and beam blockage by rain or water droplets. Because of the "thinned array curse," it is not possible to make a narrower beam by combining the beams of several smaller satellites.

For earthbound applications a large area 10 km diameter receiving array allows large total power levels to be used while operating at the low power density suggested for human electromagnetic exposure safety. A human safe power density of 1 mW/cm² distributed across a 10 km diameter area corresponds to 750 megawatts total power level. This is the power level found in many modern electric power plants.

Following World War II, which saw the development of high-power microwave emitters known as cavity magnetrons, the idea of using microwaves to transmit power was researched. By 1964 a miniature helicopter propelled by microwave power had been demonstrated.^[32]

Japanese researcher Hidetsugu Yagi also investigated wireless energy transmission using a directional array antenna that he designed. In February 1926, Yagi and Uda published their first paper on the tuned high-gain directional array now known as the Yagi antenna. While it did not prove to be particularly useful for power transmission, this beam antenna has been widely adopted throughout the broadcasting and wireless telecommunications industries due to its excellent performance characteristics.^[33]

Wireless high power transmission using microwaves is well proven. Experiments in the tens of kilowatts have been performed at Goldstone in California in 1975^[34][35][36] and more recently (1997) at Grand Bassin on Reunion Island.^[37] These methods achieve distances on the order of a kilometer.

 

Ada lagi soalan, adakah sebuah gelombang boleh ditukarkan menjadi tenaga? Kalau dikatakan gelombang yang boleh dihantar adalah 2.4GHz seperti diatas, jadi berapakah nilainya dalam tenaga (W/VA)?

iskandar wrote:

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aku tak paham.....................
lantak laa ko.

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Banyak jenis penghantaran tanpa wayar yang diterangkan dalam WIKIPEDIA, antaranya melalui Laser, Frekuensi dsb. Antara yang menariknya adalah melalui frekuensi, iaitu suatu yang tidak terlalu janggal bagi kita untuk tahu apakah itu frekuensi serta dalam masa yang sama dapat meneruskan pemahaman bagaimana frekuensi ditukar menjadi tenaga. Ayuh bincangkan bersama!

Kehebatan pengkaji dan penyelidik mencari asas penghantaran tidak mungkin tercapai jika guna kaedah yang sedia ada. Perlu keajaiban idea yang tak pernah terfikir. Macam thomas buat lampu dan Alexendar buat talipon

Secara teorinya, ianya adalah untuk menjadi begini:

 

Wireless light: Marin Soljacic (top) and colleagues used magnetic resonance coupling to power a 60-watt light bulb. Tuned to the same frequency, two 60-centimeter copper coils can transmit electricity over a distance of two meters, through the air and around an obstacle (bottom).
Credit: AMPS/MIT Libraries (top); Bryan Christie Design (bottom)

 

Tak ada yang mustahil di dunia ini. Selagi manusia sentiasa berfikir. Ayuh rungkaikan bersama!

Frekuensi mungkin boleh tetapi tidak praktikal untuk semua perkara.. sebab penghantaran tenaga melalui frekuensi ni adalah berbeza dengan penghantaran tenaga secara AC (penjanaan).. Kita lihat masalah2 berikut :-

1. bagaimana motor hendak diaruhkan ? frekuensi takde VA power..
2. kalaupun frekuensi bole carry real power (adakah cukup) & cekap untuk heating??
3. ratio tenaga frekuensi dengan AC mungkin 1 nisbah 100.. Kita perlukan 100 kali ganda kekuatan frekuensi untuk menghasilkan 1 watt tenaga AC yang sama..bila frekuensi terlalu tinggi, boleh menghasilkan radiasi yang melampau.. Bhy kanser plak jadinye..

Jadi frekuensi(gelombang) ni sesuai untuk membawa maklumat (signal) je.. (maklumat required less enegry).. untuk menggantikan AC sebagai tenaga ia perlu dikaji semula..