The bifilar pancake coil at its resonant frequency

[TinselKoala]

The original question was, which current direction generates the collapsing magnetic field of coil. This direction is the opposite to the current, which created this magnetic field.

Are you sure you don't mean "the collapsing magnetic field generates which current direction"? Regardless of your scrambled verbiage (I realize English isn't your first language) .... now you may please explain why and how the LED flashes in my video demonstration.

What's that I hear? Sound of crickets chirping....

http://www.youtube.com/watch?v=X66foYixu9Y

[TinselKoala]

WireLESS power transmission, no capacitive coupling involved:

http://www.youtube.com/watch?v=gi-hl2W86yk

Note bulb can be  _brighter_  when powered wirelessly than when connected directly to the battery powering the wireless transmitter.

[NRamaswami]

I have to beg to disagree based on my observations.

I agree that light can be made to be brighter wirelessly than when connected to the grid. That part is correct by observations.

However I have checked with a 40 watts tube light and it glows only up to the part where my hand catches it near the receiver coil. The feet wearing rubber slippers are on an insulated copper plate connected to earth. As I moved the hand further tube glows till hand is touching the light.

However if I just place the tube light between the two aerials one of them is transmitter and other receiver the Whole tube glows. In your video posted you use a tiny lamp and so you are not able to observe it but capacitance is through your body.

This is not really important. The real thing is how do we find out resonance or calculate it. If we can create something that is resonant with cosmic rays then we have electricity to be generated any where and everywhere at any time.

Your ring is very low power for you need to go very close to it to make wireless transmission to happen.
That can be very easily improved.

Regards

Ramaswami

WireLESS power transmission, no capacitive coupling involved:

http://www.youtube.com/watch?v=gi-hl2W86yk

Note bulb can be  _brighter_  when powered wirelessly than when connected directly to the battery powering the wireless transmitter.

[nelsonrochaa]

Sure I would be happy to explain this to you again.  Typically high-frequency voltage travels down the single wire.  However, with no current flow you cannot transfer any AC power into the load.  So the question is how do you get current to flow when there is no apparent current loop in the circuit?  As we know, for current to flow, there must be a loop.

We also know that there exists so-called "stray" (a.k.a. parasitic) capacitance everywhere.  A capacitor is just two conducting plates separated by a distance.  Let's look at a trivial example.  Suppose you are outside in your back yard.  Let's say there is an insulating plastic lawn chair that you are sitting in and your feet are not touching the ground.  We know that the ground is conductive and there is always some moisture in the ground that helps it become more conductive.  We also know the human body is basically salty water, and so the human body is conductive.

Therefore, when you sit on an insulating plastic chair in your back yard with your feet not touching the ground we can say that there is a measurable capacitance between your body and the ground.  It may be very small, perhaps 100 pF, but it is there and it is measurable.  In reality, there is stray or parasitic capacitance everywhere.

It is this stray capacitance that allows AC current to conduct in a current loop that allows for so-called "single wire power transmission."

Here is a typical circuit current loop:

<earth ground> ---> <stray capacitor #1> ---> <high frequency AC signal generator> ---> <load> ---> <stray capacitor #2> ---> <back to earth ground>

When you do a "single wire power transmission" experiment there are typically two "invisible" stray capacitors that allow AC current to flow.  Therefore the load sees both voltage and current and therefore AC power gets transferred into the load.  Small neon lights and LEDs require very little power to light up and that's why you often see them lit in experiments like this.

This is a fairly straightforward concept that should be understood by people interested in experimenting with electronics.

I'm impressed with such detail of explanation !
Thanks,  I will apply that to my future work . I'm feel fascinating, and for sure is a  straightforward concept that i need learn .
Thanks MH for your contribution


Nelson Rocha

[TinselKoala]

I have to beg to disagree based on my observations.

You may disagree, but your observations apparently are not of my system, and your preconceptions are causing you to draw incorrect conclusions.

I agree that light can be made to be brighter wirelessly than when connected to the grid. That part is correct by observations.

The system I demonstrated in that video is not connected to the grid in any way. It is simply powered by a single 12 volt SLA battery of 7 A-H capacity.
The bulb is a standard automotive dome light bulb.

However I have checked with a 40 watts tube light and it glows only up to the part where my hand catches it near the receiver coil. The feet wearing rubber slippers are on an insulated copper plate connected to earth. As I moved the hand further tube glows till hand is touching the light.

However if I just place the tube light between the two aerials one of them is transmitter and other receiver the Whole tube glows. In your video posted you use a tiny lamp and so you are not able to observe it but capacitance is through your body.

The bulb I used is an incandescent bulb, not a "tube light" or fluorescent light. The system is an electromagnetically coupled system, does not depend on the electric field and there is no capacitance involved in the power transmission itself. It works regardless of whether my hand is involved or not. In the case of the video demonstration above I simply held the receiver and bulb in my hand for convenience so that it would be easy and unambiguous to tell that I made no "tricks" just connected the bulb directly to the battery, and then to the wireless receiver without making any changes.

This is not really important.

On the contrary. It is very important that experiments and demonstrations be correctly interpreted. Perhaps it is my fault for not including a voiceover explanation in that video.

The real thing is how do we find out resonance or calculate it. If we can create something that is resonant with cosmic rays then we have electricity to be generated any where and everywhere at any time.

The demonstrated system is doubly resonant. The transmitter uses a self-resonating circuit that automatically attains resonance in the L-C output circuit and maintains it. The receiver uses another LC circuit (made of only one capacitor and the "antenna loop") tuned to the correct frequency of the transmitter. We "find out" resonance by using test equipment such as oscilloscopes, and we "calculate" resonance based on component values and a few well-known and well-studied mathematical equations. But you know this already.

The power density of cosmic rays at the Earth's surface is actually quite small, thank goodness. The atmosphere and the Earth's magnetic field protect us from most of the power streaming at us from space, which is a good thing because otherwise life would have a hard time existing here on Earth.

Your ring is very low power for you need to go very close to it to make wireless transmission to happen.
That can be very easily improved.

That much, at least, you have correct. I am demonstrating a low power system in the close quarters of my bedroom laboratory, using a small 12 volt battery as the power source.

Regards

Ramaswami