Tesla's Magnifying Transmitter "Replications"

[Farmhand]

As far as the technical stuff go's.

I think if anyone is interested in the technical side of things with all the really complicated stuff then Eric Dollard's works and papers are the way to go.

Definately. And even I can take a lot of good info in from his papers and video's. Athough I think in picture's not numbers. Unfortunately for me. Sometimes I get things completely back to front.

[Farmhand]

Well this is interesting from 1894.



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Very telling page.

From here. Page 348.
The inventions, researches and writings of Nikola Tesla, with special reference to his work in polyphase currents and high potential lighting : Martin, Thomas Commerford, 1856-1924 : Free Download & Streaming : Internet Archive

[Kokomoj0]

I do agree with Meyl on some points, such as the transmitter and receiver terminals have alternating voltages 180 degrees out of phase. When one is high the other is low I think. But I can only say what I think going by my deductions. And from the Tesla info I've studied.


you can use that to tune your transmitter to your receiver.

put your scope on both one probe on each, (set the voltages approximately to the same value) and then hit the add button.

when the 2 waves turn into a flat line you are "perfecty" tuned.

[Farmhand]

Hey dr, I did some rough calculations and came up with about 132 pF or 2.2 nF for you're primary capacitors.

This is how I worked it. Using this calculator with only rough figure's, the wire lengths were still not right so some more playing with the numbers might help.

Spiral coil calculator
Flat Spiral Coil Calculator

LC frequency calculator.
L/C Resonance Calculator

These should get close to a good cap value.

From my deductions I estimate my own Toroid terminals to be about 5 or 6 pF. They are fairly big. So I used 4 for the calc.

I got 82 uH for a 23.5 turn secondary with a 60mm inner and 276 mm outer diameter, but that was 12.4 meters of wire.

So just for example going by these figure's with a 4 pF terminal capacitance the secondary would be resonant about 8.761 Mhz.

I got 2.6 uH for a 2 turn primary 280 inner 300mm outer diameter. But that is 1.8 meters of wire.

So to make the primary ring at 1/4 of that secondary frequency or 2.1 Mhz would require a 2.2 nF capacitor.

Or to make it ring at 8.7 Mhz it would need about 132 pF.

This above is just for example, if you use the actual dimensions of you're coil or measure inductance as well as determine the capacity of you're terminals you could better determine the primary capacitance required, but still to get optimum performance some tuning is needed for any coils I think as far as the primary to secondary frequencies are concerned.

I think with spark gaps most people adjust the primary capacitance and/or adjust the primary inductance by using taps on the primary.

Anyway dR I think you're frequency is about 8 Mhz. Or a bit more.

What is the primary capacitance you're using now ?

Cheers

I think that's about right for the example I hope someone will let me know if it's wrong.
.

[dR-Green]

Hi Farhmand. Those calculations don't sound too far off I don't think I forgot how to calculate capacitors in series, but I have 2x 680pF and 1x 500pF in series, so I'm guessing it would be somewhere around the number you said. It's better with lower capacitance.

And I forgot to answer the one question I replied to answer last night, I do have identical caps on the transmitter and receiver. But these are all the caps I have at the moment so there's no more I can do if I want to use the transmitter and receiver.

The primary length is 1.79 metres (I just measured it), secondary around 13.5 metres. I'll have to use some maths to calculate the exact secondary length.

Thanks for posting that info

[Farmhand]

Hi dR, I think the mistake I made, or one of them, was I used 4mm turn spacing, maybe I should have used 3.4 mm or something to get the wire lengths correct.

Anyway about 132 pF sounds good for a high frequency setup and the current draw in you have seems to me to be pretty good. So I think you almost nailed it.

2 x 680 pF and 1 x 500 pF.
That works out to about 200 pF which is course is probably very close to the right amount.

Good job.

[MonsieurM]

Farmhand, pretty waveform you got there...i would like to propose if you going to use an antenna a Caduceus coiled on a magnet maybe for sensitivity purpose) ...just a thought

[Farmhand]

Farmhand, pretty waveform you got there...i would like to propose if you going to use an antenna a Caduceus coiled on a magnet maybe for sensitivity purpose) ...just a thought

Yeah that waveform was just an effect of the scope and changing frequency I think.

Anyway I found this Caduceus type effect noted in this Book I'm studying.
On page 398 and the explanation of the experiments and observations carry on through page 399 and 400 I think.
The inventions, researches and writings of Nikola Tesla, with special reference to his work in polyphase currents and high potential lighting : Martin, Thomas Commerford, 1856-1924 : Free Download & Streaming : Internet Archive

I think a vacuum tube was used.


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[dragon]

Farmhand wrote:"It was Tesla who said the capacitor in the primary circuit magnifies the current and therefore the current in the terminal. I believe him and I think it is necessary to transmit power. It's necessary for the system to be able to be able to build such a high potential and maintain it, while transmitting. "

What happens when you take a capacitor of say .005uf charged to say 5000 volts and discharge it into a primary coil of say 4 uh? 90% of the discharge is converted to current in an instant. If we take the formula V(C/L)^.5 we can find the approximate discharge current...

5000*(.005/4)^.5 = 176 amps or more closer to 150 or a little less when its done, leaving a voltage circulating of around 500 volts in the primary. How much of that current is transferred to the secondary?

You can generate a megawatt pulse quite easily with very little energy using the capacitive discharge methods described by Tesla. "The condenser is a magnificent device"

[mikrovolt]

Freqency multipliers together with coupling space charge (gaps) in resonance
can capture time space energy.

Concider way back, the spark gap as a frequency multiplier.
Frequency multiplier - Wikipedia, the free encyclopedia

there are simpler ways
Simple "Small Signal" Harmonic Generator with wide range output power setting

If you find where Tesla said something in this regard it would be interesting.

[Farmhand]

Farmhand wrote:"It was Tesla who said the capacitor in the primary circuit magnifies the current and therefore the current in the terminal. I believe him and I think it is necessary to transmit power. It's necessary for the system to be able to be able to build such a high potential and maintain it, while transmitting. "

What happens when you take a capacitor of say .005uf charged to say 5000 volts and discharge it into a primary coil of say 4 uh? 90% of the discharge is converted to current in an instant. If we take the formula V(C/L)^.5 we can find the approximate discharge current...

5000*(.005/4)^.5 = 176 amps or more closer to 150 or a little less when its done, leaving a voltage circulating of around 500 volts in the primary. How much of that current is transferred to the secondary?

You can generate a megawatt pulse quite easily with very little energy using the capacitive discharge methods described by Tesla. "The condenser is a magnificent device"

Hi Dragon,

Yes I see, I believe that is true. I would like to calculate the current and voltage in my circuit but I get confused by the numbers and I don't know what the symbols all represent.

At the moment I have about 6.6 nF primary capacitor with a 10 turn primary coil @ 0.018 mH with 0.2 Ohms resistance. I'm using a 12 volt battery to power the circuit. But the charging inductor has minimal inductance and is before the capacitor. So

Can anyone tell me my primary current and voltage ?

Secondary has a lot of turns, but I'm mainly interested to understand the primary circuit current.

As far as I can tell I am pulsing the primary circuit at about 460 - 480 Khz depending. I can adjust the primary capacitance down 1.3 nF, inserting a core in the charging inductor increases its inductance but I don't use anyway it because it's not necessary as yet.

Thanks

P.S. I think understanding the current and energy in the primary circuit will help to know what can be expected from the receiver output coil, as it is identical.

..

[Farmhand]

Freqency multipliers together with coupling space charge (gaps) in resonance
can capture time space energy.

Concider way back, the spark gap as a frequency multiplier.
Frequency multiplier - Wikipedia, the free encyclopedia

If you find where Tesla said something in this regard it would be interesting.

Hi mikrovolt,
I wouldn't doubt that either, I think there could be several different ways to accomplish it to a degree, probably some much easier ways these days.

I'll keep my eye open for references to that kind of thing by Tesla. dRGreen mentioned something about "odd" number multiple harmonics or something and I remember reading it in a patent too, one of them.

[dragon]

Hi Dragon,

Yes I see, I believe that is true. I would like to calculate the current and voltage in my circuit but I get confused by the numbers and I don't know what the symbols all represent.

At the moment I have about 6.6 nF primary capacitor with a 10 turn primary coil @ 0.018 mH with 0.2 Ohms resistance. I'm using a 12 volt battery to power the circuit. But the charging inductor has minimal inductance and is before the capacitor. So

Can anyone tell me my primary current and voltage ?

Secondary has a lot of turns, but I'm mainly interested to understand the primary circuit current.

As far as I can tell I am pulsing the primary circuit at about 460 - 480 Khz depending. I can adjust the primary capacitance down 1.3 nF, inserting a core in the charging inductor increases its inductance but I don't use anyway it because it's not necessary as yet.

Thanks

P.S. I think understanding the current and energy in the primary circuit will help to know what can be expected from the receiver output coil, as it is identical.

..

According to the formula 12*(.0066uf/18uh)^.5 = .229 amps or 229ma into the coil. Voltage is the key for high current discharges.

24V*(.0066/18)^.5 = .459, 48V = .919, 1000V = 19A 5000V = 95A and so on using your current coil and cap arrangement. The key to a massive discharge is an extremely low inductance with as high of capacitance as your resonance will allow. By reducing the turns of the primary and increasing the capacitance, matching the secondary's resonance the amperage would increase considerably. It appears that your finding resonance at around 461khz according to your values so if you replaced the cap with a .029uf and dropped the inductance down to 4uh you would have the same frequency needed to bring the secondary into resonance and the amperage in the primary would jump to 1.02 amps.

The drawback to using a transistor is you have to drive the circuit at the frequency desired. A spark gap will allow it to occur naturally.

The amperage transfer into the secondary would be based on the loose coupling % and the wire size on the secondary. Note that most of tesla's high power projects consisted of very large wire. He noted in one of his papers that if he brought a piece of tin foil in close proximity of the primary coil it would explode or disintegrate. I'm assuming this was caused by inductive heating on a massive scale.

Fun stuff indeed.

[Farmhand]

According to the formula 12*(.0066uf/18uh)^.5 = .229 amps or 229ma into the coil. Voltage is the key for high current discharges.

24V*(.0066/18)^.5 = .459, 48V = .919, 1000V = 19A 5000V = 95A and so on using your current coil and cap arrangement. The key to a massive discharge is an extremely low inductance with as high of capacitance as your resonance will allow. By reducing the turns of the primary and increasing the capacitance, matching the secondary's resonance the amperage would increase considerably. It appears that your finding resonance at around 461khz according to your values so if you replaced the cap with a .029uf and dropped the inductance down to 4uh you would have the same frequency needed to bring the secondary into resonance and the amperage in the primary would jump to 1.02 amps.

The drawback to using a transistor is you have to drive the circuit at the frequency desired. A spark gap will allow it to occur naturally.

The amperage transfer into the secondary would be based on the loose coupling % and the wire size on the secondary. Note that most of tesla's high power projects consisted of very large wire. He noted in one of his papers that if he brought a piece of tin foil in close proximity of the primary coil it would explode or disintegrate. I'm assuming this was caused by inductive heating on a massive scale.

Fun stuff indeed.

Ok thanks a heap. Pathetic numbers I know. But I'm just experimenting.
If I reduce the inductance too much the solid state switches don't seem to
like it much. I've got better fets now though.

I did run this setup with a 4 turn primary and I think 0.1 uf or 0.2 uf
not sure now, it did work pretty good but the current and voltage was a bit
much. But I am going to increase the voltage soon with a doubler. Maybe a
few less turns on the primary after I get to the voltage I want to use.

I can make the analogue current meter read 800 Ma now fairly easy, does
that calculation also include current flowing from the source ? Or just the
primary cap discharge ?

Because it occurs to me if the cap discharge through the primary is quicker
than the PW duration time then current will flow from the source battery also,
as in the cap has discharged but the fet is still on.

I see, that info is usefull, this would indicate the correct PW to use
is small not 50/50, and the best practice would be to use a de-Q-ing diode as
well as going for the least turns and most capacitance as possible without
burning up the switches, for more current for the voltage used. And of course
Thicker wire for less resistance.

As close as coupling as the voltage will allow for Solid state I think.
Any thoughts on that point ?

What about sidacs in place of spark gaps for medium voltage setups ?

Couple of idea's. Just idea's.


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Cheers

[Farmhand]

According to the formula 12*(.0066uf/18uh)^.5 = .229 amps or 229ma into the coil. Voltage is the key for high current discharges.

24V*(.0066/18)^.5 = .459, 48V = .919, 1000V = 19A 5000V = 95A and so on using your current coil and cap arrangement. The key to a massive discharge is an extremely low inductance with as high of capacitance as your resonance will allow. By reducing the turns of the primary and increasing the capacitance, matching the secondary's resonance the amperage would increase considerably. It appears that your finding resonance at around 461khz according to your values so if you replaced the cap with a .029uf and dropped the inductance down to 4uh you would have the same frequency needed to bring the secondary into resonance and the amperage in the primary would jump to 1.02 amps.

The drawback to using a transistor is you have to drive the circuit at the frequency desired. A spark gap will allow it to occur naturally.

The amperage transfer into the secondary would be based on the loose coupling % and the wire size on the secondary. Note that most of tesla's high power projects consisted of very large wire. He noted in one of his papers that if he brought a piece of tin foil in close proximity of the primary coil it would explode or disintegrate. I'm assuming this was caused by inductive heating on a massive scale.

Fun stuff indeed.

That little bit of info you gave me by doing the calculation is very useful, it tells me I should have a larger charging inductance and a larger primary capacitance and fewer primary coil turns. But how big the charging inductance can be ?

Ok what I'm wondering is --- Does the charging inductor on the primary resonant charging circuit factor into the calculation for resonant frequency ?

Because the primary cap discharges into the primary coil only.

I guess I can check that to see if it changes it, when I put it back together.

I'll put it back together and check what gives with De-Q-ing diode. I'll use a schottky.

Ta