I watched an episode of the Gadget Show which showed a small circuit which lit up the led and fed off the power from the microwaves coming in and out of a cell phone converting RF to Electric, I had a look for a circuit to do that but found nothing, is there some kind of secret underground world of EMF electronics going on?...

Thanks...

 

IF YOU HAVE SEEN THE GADGET THEN YOU MUST HAVE NOTICED THAT THERE IS A COIL LIKE ANTENNA AS A RECEIVER FOR THE CKT
IT RECEIVES RF/MV AND CONVERT IT TO THE ELECTRICAL SIGNAL
AS YOU KNOW THAT IS EMF THEN YOU MUST BE KNOWING THE PROPERTIES OF EMF
DO SOME THING GOOD DON'T JUST........

 

IF YOU HAVE SEEN THE GADGET THEN YOU MUST HAVE NOTICED THAT THERE IS A COIL LIKE ANTENNA AS A RECEIVER FOR THE CKT
IT RECEIVES RF/MV AND CONVERT IT TO THE ELECTRICAL SIGNAL
AS YOU KNOW THAT IS EMF THEN YOU MUST BE KNOWING THE PROPERTIES OF EMF
DO SOME THING GOOD DON'T JUST........

i agreed

 

If you live close enough to a high power line, picking up electricity through wireless means should be easy enough.

 

If you live close enough to a power line, you can even steal a little power, enough for a small light bulb. It is enough to get you into legal trouble, in the USA it is call "Theft of Service". I doubt they would notice an LED though.

 

ha ha ha aaaaaaaaaaa
good
do the us agencies have time to see the LED powered wireless le he he heeeeee

 

It's actually pretty easy to do. Wind a coil, a big one, and that should do it. If you want to enhance the effect add a capacitor, and try to make it resonant to whatever the line freq is in your area.

I'm describing this only for experiment. I'm not joking about it being illegal, many a farmer whose barn was next to high power lines and figured they would never notice that small light bulb found out it is not a joke. The power companies take losses seriously, partly because it could be a safety issue.

High tension lines throw out quite a field.

 

This reminds me a little of the television police in the UK. Someone in another thread mentioned that the government does not charge for listening to the radio, I think. This is not true in England.

 

Yeah, when my Dad was stationed at Lakenheath Air Force Base in the early 60's we had to pay for the privilege, but I got to see the premier of Dr Who! I was raised an Air Force brat.

We have a lot of UK members here. Maybe they could tell us the legalities of a crystal radio?

 

It's actually pretty easy to do. Wind a coil, a big one, and that should do it. If you want to enhance the effect add a capacitor, and try to make it resonant to whatever the line freq is in your area.

I'm describing this only for experiment. I'm not joking about it being illegal, many a farmer whose barn was next to high power lines and figured they would never notice that small light bulb found out it is not a joke. The power companies take losses seriously, partly because it could be a safety issue.

High tension lines throw out quite a field.

you are 100% right
we use to play with the coils in our school days
believe me it can dangerous to the life
you have to take preoccupations first
especially who don't know the statics & emf power's

 

Hello,

Phone maker Nokia seems to be busy with it.
http://beta.technologyreview.com/communications/22764/

The harvested power is not enough yet.

Greetings,
Bertus

 

You can buy these commercially from the phone gadget suppliers. I've even seen cellphone covers with little leds in that light up when the phone rings.

 

Nah they just detect the increase in microwaves coming out of the phone and flash on and off with their own power source, i'm talking about taking those microwaves and stealing their energy to charge the phone or light up an LED etc etc

 

Nah they just detect the increase in microwaves coming out of the phone and flash on and off with their own power source, i'm talking about taking those microwaves and stealing their energy to charge the phone or light up an LED etc etc

Works in theory but not very practical. RF radiation power decreases at the square root of the distance, so very little practical power is available for 'harvesting'.

Lefty

 

Actually they are powered by the phone's microwave energy with little antenna wires built in. It's enough power 2 inches from the phone antenna to light a few small leds.

Check the phone gadget suppliers.

 

Phone microwave energy to charge the battery?

Uhoh, another HHO scheme. Tapping into other source maybe.

Also a good way to have your signal abrubtly disconnect. That energy was meant to be used for something else.

 

Hi.
The harvesting of electromagnetic fields from power lines and broadcasting in general to produce 'some' energy to recharge a battery was a subject discussed in another forum years ago, and somehow the final thought seemed that tuning into resonance to the most powerful/nearby source of EMF would not be the optimal approach.

I remember little details, but went towards plain rectification at the end of a long wire, to capture all radiation at all frequencies. Any opinions on this?

Such long wire would not apply on a portable unit.

In this subject of picking the EMF from the air, I have a doubt on how to tap energy from resonating circuits:

A parallel resonant

A-------||---------G
A------coil--------G

A series resonant

A-------||-----coil-------G

being A an antenna and G ground,

Where/which/how is it more convenient to tap/insert rectification ? How would you do it ?

One resonant circuit will have low voltage and higher current; the other higher voltage at low current