Is Wireless Power Transmission Feasible for Charging Mobile Phones?

[probableexist]

wireless power transmission: a new method

I was having an idea that if i can somehow reverse the operation of Voltage controlled oscillator i.e if i can make the circuit to input high frequency(e.g radio wave) and give output in proportional amplitude(or voltage) then if i can glow even a small bulb it would be a good final year project to work on and very excited about this idea.my questions are :is this possible? and is this new idea or already this has been invented(so that i don't violate any patent laws unknowingly)?.i need a expert opinion on this because i am seriously considering this as my final year project.Can any expert guide me on this e.g what books to study,what subjects to master,how to go about this project etc. provided this idea is possible. Thank you.

 

[fss]

Wireless power is a fairly active area of research.

http://www.wirelesspowerconsortium.com/

 

[probableexist]

my next question is: do i need take their permission from them to do it as my final year project?.Also i would like to tell that in my idea i am not using their principle of operation because they are using L-C circuits and rectifiers,diode etc.My idea is to use VCO in reverse operation in receiver end and normal operation in transmitter end.please advice me as i do not want to violate any intellectual property laws unknowingly.can any PF mentor advise me on this whether my idea is conceivable or not?.thanks.

 

[berkeman]

I was having an idea that if i can somehow reverse the operation of Voltage controlled oscillator i.e if i can make the circuit to input high frequency(e.g radio wave) and give output in proportional amplitude(or voltage) then if i can glow even a small bulb it would be a good final year project to work on and very excited about this idea.my questions are :is this possible? and is this new idea or already this has been invented(so that i don't violate any patent laws unknowingly)?.i need a expert opinion on this because i am seriously considering this as my final year project.Can any expert guide me on this e.g what books to study,what subjects to master,how to go about this project etc. provided this idea is possible. Thank you.

my next question is: do i need take their permission from them to do it as my final year project?.Also i would like to tell that in my idea i am not using their principle of operation because they are using L-C circuits and rectifiers,diode etc.My idea is to use VCO in reverse operation in receiver end and normal operation in transmitter end.please advice me as i do not want to violate any intellectual property laws unknowingly.can any PF mentor advise me on this whether my idea is conceivable or not?.thanks.

Transferring power from coil to coil is a standard technique, and you would not need permission to experiment with doing that. In the link above, there may be some patents covering the feedback communication technique (using impedance modulation), but it doesn't sound like that is part of your project, and even so, if you are just doing this as a school project, and not for sale, you would be able to experiment with that part of the circuit as well (but always give attribution in your project to where ideas came from).

I don't understand your references to VCO techniques in this context. Could you post a block diagram of your proposed system?

 

[vk6kro]

my next question is: do i need take their permission from them to do it as my final year project?.Also i would like to tell that in my idea i am not using their principle of operation because they are using L-C circuits and rectifiers,diode etc.My idea is to use VCO in reverse operation in receiver end and normal operation in transmitter end.please advice me as i do not want to violate any intellectual property laws unknowingly.can any PF mentor advise me on this whether my idea is conceivable or not?.thanks.

You may have a wrong idea about how a VCO works.

The circuit gets its power from a battery or power supply. The control voltage varies the capacitance of the varactor (varicap) diodes which are across the tuned circuit of the oscillator. This causes the frequency of the oscillator to change.

The oscillator does not get its power from the control voltage and the diodes used are a type that is inefficient as a rectifier at the oscillation frequency, so little rectification takes place.

 

[probableexist]

ok, can i make the VCO circuit work the other way round i.e input is some high frequency signal and output is some voltage proportional to the input frequency and this is some stupid question i not able to upload the block diagram of my idea,i made it in paint and not able upload it.Mr vk6kro how did you upload this circuit diagram along with your reply and by the way thank you Mr Berkeman and Mr vk6kro for your replies.

 

[Fish4Fun]

probableexist,

here is the function you are talking about:

http://focus.ti.com/lit/ds/sbvs015/sbvs015.pdf

But, I get the impression you are attempting to get POWER from RF signals. Any POWER in the circuit is supplied by the power source driving the circuit, not coming from the signal source.

Fish

 

[probableexist]

Thank you, the power source for the circuit is different and derived from Battery separately i am only want to transmit electrical power from one point to the another and not using the control voltage as the power source for the circuit

 

[Fish4Fun]

As a side note, there are some existing circuits that are actually powered by RF, primarily some "smart-cards" are powered by RF, but this technology requires careful power management. Typically RF is rectified and used to charge a capacitor. The uController then performs some predefined number of operations before returning to low-power mode while the capacitor is re-charged. Here is an article on applying battery source power management to an RF powered device:

http://www.google.com/url?sa=t&sour...sg=AFQjCNE4IZZ5u2xuEece40RM0mAwrPGtIQ&cad=rja

The industry in general is not very forthcoming with the technology involved in powering RF smart cards. Likely two reasons: 1) Smart card technology in general is vulnerable to attack, and keeping specifications to the vaguest possible level is the norm, 2) The RF power supply is typically part of a much larger integrated circuit / system, and it is not readily migrated to any other application.

Just thought I would add this note about an existing RF power supply.

Fish

 

[probableexist]

Thanks a lot for the materials Mr Fish4Fun i will study this first and related references and reply later ok bye.

 

[probableexist]

also please stay in contact as i might not get time to study this for this month as my semester exams are going on throughout this month and will end not before the first week of January.tomorrow i am having my exam wish me luck and again thank very much for all this materials and i am not feeling like to give exam tomorrow i am very excited about this idea.I am doing undergrad EE.thank you again!bye

 

[probableexist]

sorry,one last thing please keep advising on this thread as i will daily come online to look for new advise and new materials please do not stop writing your valuable suggestions on this thread PLEASE!

 

[probableexist]

Mr Vk6kro can i use voltage to frequency converter in transmitter part and frequency to voltage converter in receiver end this two ICs are provided by Texas instruments and by this can i transmit enough power to charge mobile phones wirelessly?
if not how can i increase the power transmitted so that i can charge mobile phones?.thank you

 

[vk6kro]

ok, can i make the VCO circuit work the other way round i.e input is some high frequency signal and output is some voltage proportional to the input frequency and this is some stupid question i not able to upload the block diagram of my idea,i made it in paint and not able upload it.Mr vk6kro how did you upload this circuit diagram along with your reply and by the way thank you Mr Berkeman and Mr vk6kro for your replies.

[PLAIN]http://dl.dropbox.com/u/4222062/PLL2.png

You can put the VCO in a phase locked loop.
In this you compare the VCO frequency with an input frequency in a phase detector which will then send a control voltage to control the VCO to pull it onto the same frequency as the input frequency.

The control voltage needed to do this depends on the input frequency. This can be used to demodulate FM signals.

The 74HC4046 chip has a very nice phase detector in it that can be used to do this.

Note that the VCO can only be controlled over a fairly small range of frequencies by varying the voltage on the control line, so the phase locked loop has only a small range of frequences that it will work for.

[PLAIN]http://dl.dropbox.com/u/4222062/header.PNG

Inserting pictures.
You can attach a picture you have drawn using the paper clip thing at the top of the edit screen.
If you have a web address for the picture, you can insert it into text using the "insert image" tool at the top of the edit screen.
If you have a picture on Internet that you want to insert into text, this is mode is much more effective than attaching pictures. Attaching pictures gives you a small image that the reader has to click on and readers usually don't bother to do this.

 

[vk6kro]

Mr Vk6kro can i use voltage to frequency converter in transmitter part and frequency to voltage converter in receiver end this two ICs are provided by Texas instruments and by this can i transmit enough power to charge mobile phones wirelessly?
if not how can i increase the power transmitted so that i can charge mobile phones?.thank you

You can transmit information about the voltage like that, but you can't transmit the voltage itself.
You might like to know the voltage your solar panels are generating, so you could transmit this information over a radio link (if you can do this legally). But you can't transmit the actual voltage.

No, it is not reasonable to charge your mobile phone from radio transmissions.