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Old 03-30-2012, 08:15 PM
Nhopa Nhopa is offline
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Join Date: Nov 2011
Posts: 134
Congratulation dR-Green

Originally Posted by dR-Green View Post
I was doing some experiments the other night with a specific goal in mind, it all started relatively unrelated to this, but one thing led to another and I decided to try the crystal radio principle in the house, seeing as the big coil I'm using to receive the radio has 4x the wire length of my small coil. So the idea was to replicate the main objective but using my own power source to try and get a better idea of things. 52.65m transmitter and 13m receiver secondary wire lengths approx.

First before I forget, a normal crystal radio can be connected to the transmitter as a one wire receiver along with tuning, and it also receives without any wires as an "AV plug" type device with tuning which may be of interest to those interested in the SEC type devices. It needs the "ground" and "terminal capacitance" to work properly whether using direct connections or not, but it will easily light LEDs.

The normal receiver worked so I tried Eric's crystal circuit with the small spiral. For the original goal I didn't want a direct connection so here I was using a tinfoil ground plane on the coil output with various bits of metal close to it to receive the energy. That worked too, but it was better when the C0 shorted (or connected directly) across the receiver secondary. Next, the power circuit. Also worked, but it was better with C2 removed from the circuit.

But the point here was I was now thinking of it in terms of the radio instead of "energy transmission". That was an interesting revelation I decided to earth the transmitter by connecting it to the radiator, and use a metal receiving plate to see if I could get anything off the radiator with no physical connection. Lo and behold the LEDs lit on the receiver And to cut an even longer story short, I used a direct connection from the radiator to the receiver was able to tune it for best output. It will even light a 15w 240v incandescent bulb very dimly, but I was very excited by the fact it even lit at all from an earthed wire. So this might not exactly be the goal of this thread, but personally I thought it might be an useful way of having some "known" source of power to be able to test the theory and learn a bit about it.

Anyway this video shows the result so far, I suppose the main thing to note of relevance here being the effect of the terminal capacitance when its distance from the radiator is adjusted. The cardboard has tinfoil sandwiched inside it. Without adjusting the distance like that it would need pretty big terminal capacitance for the best output.

[edit] I forgot to mention, the primary is in series with the secondary for best output, and the fridge shelves are a part of the terminal capacitance.

Tesla "Wireless" Electrical Transmission Via Earthed Central Heating Pipes - YouTube
This is fantastic what you have accomplished. While theories are important it is a successful experiment what is the topping on the cake. Interesting to note that you have used the flat spiral coil form in your set-up. Tesla was very found of these type of coils and probably for a good reason. In the book "The Fantastic Inventions of Nikola Tesla" there is a picture of Tesla sitting front of a flat spiral coil over 2 meters in diameter and about 91 turns of wire. I would like to show the picture but I am not sure if it would not violate copy rights.
But going back to your experiment, it will give us, fellow experimenters, the needed assurance that Eric's 'crystal" radio works. It would help us a lot if you could make a sketch of your set-up to show how much does it deviate from the published circuit. Do you think that an improved grounding system would increase the performance? Did you get to the point where you started to "blow" the 1N34 diodes?