Eric Dollard

[dR-Green]

Has someone measured the complete frequency spectre with his Tesla coil?

From http://www.energeticforum.com/203695-post7.html

And http://www.energeticforum.com/204220-post12.html

[dR-Green]

When I measure the magnetic field on the secondary like this it rises from bottom till the top ring. Could you confirm this?

Is the secondary grounded? In 1/4 wave resonance the current and voltage distribution should be like this. Maximum potential at the top, and maximum current at the bottom.

[orgonaut314]

Another two pictures. This time a simulation of the Tesla coil as a network. Eric calls it the shunt concatenated network. You see the mutual capacitances on top and the mutual inductance as the first coils left. The rest is the transversal transmission line. Don't mind the resistors they are there for the simulator only.



The voltage seems stronger with 4 elements and the same 0,7V input. It has the same type of resonance as the longitudional network.



Looks like this one:


Has someone measured the complete frequency spectre with his Tesla coil? DrGreen?

[orgonaut314]

When I measure the magnetic field on the secondary like this it rises from bottom till the top ring. Could you confirm this?

[orgonaut314]

That is strange. In your case the magnetic field is lowest at the top of the secondary coil.

I restudied the longitudional simulation and it shows the current is most at the last coil. For details I had to multiply the coils current by 1/2 exept the last coil because the simulation did not allow two equal coils parallel. So you see in the picture a rising current from L2 till 2*L5. I zoomed in on the highest resonance.

[dR-Green]

I have one question. Did anyone measure the magnetic field on the secondary coil and was it maximum at the top? It should be if the longitudional network is right but I never measured. Thanks.

Ok done a measurement and indeed the magnetic field is stronger on the last loop of the coil

Design frequency = 3670 kc

New Extra Coil #3 + 20% 20 turn secondary









New Extra Coil #3 + 15% 17 turn secondary

Tuned secondary



Free secondary

[dR-Green]

Ok I am going for a little less rigorous earth. I have one copper tube in the ground now and I will add three more to start with in a sort of circle. Now I have to make a doghouse to cover the coil under it.

I'm aiming for transmission/reception for the CRI and other experiments, so I plan to use the biggest area I can get from the garden. This is not least due to doing experiments in the past and observing how the received power is directly affected by the depth of the receiver earth terminal.

[orgonaut314]

He I get it. This is in fact the analoque of the Tesla coil:


But if you simulate this one it behaves like the longitudional network.

The Alexanderson network is in fact a little different. I wonder why Eric stil thinks the Alexanderson antenna can replace a Tesla coils or is even better.

The Alexanderson has the shunt K in series with L.

[orgonaut314]

Looking up materials for constructing the earth terminal, it turns out that regular earth rods are not so good after all.

Rod length = 1.2 metres, diameter = 14mm
Length is not enough requiring at least double the number of rods + connectors
Cost for 34 rods for length (depth) of 2.4 metres + 17 connectors = £241.23

Copper pipe length = 3 metres, diameter = 15mm
Cost for 20 copper pipes = £122.40

Plus 3 pipes left over. Also iron and steel pipes and rods are more expensive so copper pipes is the way to go.

Ok I am going for a little less rigorous earth. I have one copper tube in the ground now and I will add three more to start with in a sort of circle. Now I have to make a doghouse to cover the coil under it.

[orgonaut314]

I have one question. Did anyone measure the magnetic field on the secondary coil and was it maximum at the top? It should be if the longitudional network is right but I never measured. Thanks.

Ok done a measurement and indeed the magnetic field is stronger on the last loop of the coil

[orgonaut314]

I don't think anyone claimed there would

Due to the complications with the tentative extra coil calculations Eric did advise to experiment with an extra coil driven by an LMD network instead of the secondary for the concatenated resonance.

Looks good that the frequencies can be accurately simulated. There are 5 inductors in your simulation though so maybe how the "element" is defined isn't perfect.

Yes you are correct. Eric always said the coils could be calculated it just took the solution of 4th order differential calculations an effort that was never finished.

In the Borderland video the network actually contained 4 elements. With 5 elements the frequencies are off. The internal resistance of the powersupply greatly influences the voltage so I guess the simulation is pretty good

I also found out that the voltage and the current are greatest at the last coil compared to the first coil just as Eric measured. The network is a very wild one. I'll post a simulation of the voltage and power (reactive power) from the last coil. Driven with 0,7V the vallues are nice but driven with 220V I got 1MegaWatt reactive power and peaks of 50kV!!!


Voltage final coil Vin=0,7V:


Reactive power final coil Vin=0,7V:


Vin=220V


Vin=220v Reactive power of 1MegaWatt!

[dR-Green]

Notes On Operation Earth Point

Looking up materials for constructing the earth terminal, it turns out that regular earth rods are not so good after all.

Rod length = 1.2 metres, diameter = 14mm
Length is not enough requiring at least double the number of rods + connectors
Cost for 34 rods for length (depth) of 2.4 metres + 17 connectors = £241.23

Copper pipe length = 3 metres, diameter = 15mm
Cost for 20 copper pipes = £122.40

Plus 3 pipes left over. Also iron and steel pipes and rods are more expensive so copper pipes is the way to go.

[dR-Green]

So the power from the coil will not be anything like over unity.

I don't think anyone claimed there would

Due to the complications with the tentative extra coil calculations Eric did advise to experiment with an extra coil driven by an LMD network instead of the secondary for the concatenated resonance.

Looks good that the frequencies can be accurately simulated. There are 5 inductors in your simulation though so maybe how the "element" is defined isn't perfect.

[orgonaut314]

Now since this is a coil element we could in principle simulate the coil



Tesla did not have Orcad LOL

[orgonaut314]

He guys I simulated the experiment Eric Dollard did with the longitudional network. Eric says he used 5 simple networks with 0,68uF and 40mH see 'Pt.3 - Algebra - Eric Dollard SFTS Powerpoint' close to the end of that doc.

When I use 4 networks my resonant frequencies are exactly right. I also simulate 0,7V input but my voltages are somewhat different. See for yourself.

It is just for fun and to illustrate that the voltages follow Kirchhofs laws and the magic is not in the vallues. I am pretty convinced that it is possible to simulate the CRI coils too with concatenated networks as Eric shows how to build them. It would take a lot to make a distributed line like the coil is but than the vallues of the voltages would probable match to the simulation.

Not usable to calculate coils I am afraid.