Open Source Project for Tesla/Jackson Wireless Transmission

[Farmhand]

Ok a little bit of research and I think I found out what I did wrong. This explains the extreme voltages I was seeing in the tank cap at some points and how I was able to get fluro's to light dimly with 50 Ma input.

Dual Resonant Solid State Tesla Coil - HvWiki

Quote from the wiki, i'll bold a bit of it.

A DRSSTC is different than the conventional SSTC due to the addition of a primary tank capacitor, hence, "Dual Resonant." When in a resonant state, the added capacitance in the primary circuit cancels the inductance leaving no reactive component. Primary current flow is now only limited by resistance in the capacitors (ESR) and resistance in the primary windings, which is usually on the order of a few hundred milliohms. In a SSTC, primary current is limited by the primary's inductance and streamer loading. This is the reason a SSTC can run CW or "continuous wave". So a key difference between SSTCs and DRSSTCs is that a DRSSTC usually operates in the transient state, while SSTCs can safely run in the steady state conditions. However, if you were to drive a DRSSTC at it's resonant frequency for too long, a steady state current of many times the safe limit might be possible. This could have the following adverse effects
IGBTs blow from overcurrent - this would happen almost instantanly (few mS) depending on the size of the IGBT.
Overvoltage of the primary capacitor - The extreme current flowing over the primary tank can create voltages tens of times more than the supply voltage. (use Ohm's law to figure out just how high)

I have to do some calculations and thinking about how to harness this problem child. There must be a way.

This is using the CEMF to add to the EMF. It should be able to be used in a fixed speed motor generator too. Like a Muller.


Cheers.

[Farmhand]

OK I've made some progress,I decided to go to a newer circuit the same and see what it could do. It is running at 20 Khz with a 13 us pulse width and consuming 220 Ma at 12.6 volts. I get a reading of 30 Ma powering the LED at the receiver.

Here is the circuit
http://wv0v9q.bay.livefilestore.com/...009.JPG?psid=1

Here is the pulses for the mosfet gate, 10v per div.
http://wv0v9q.bay.livefilestore.com/...001.JPG?psid=1

Here is the tank cap charge waveform. I had to set the scope to 100v per division to fit it on the screen.
http://wv0v9q.bay.livefilestore.com/...005.JPG?psid=1

This is the charging inductor waveform, 10v per div.
http://wv0v9q.bay.livefilestore.com/...006.JPG?psid=1

This is at the recovery diode which is not in use. 100v per div.
http://wv0v9q.bay.livefilestore.com/...007.JPG?psid=1

And this is a small fluro lit up and levitating at 45 degree's on the top of the transmitter.
http://wv0v9q.bay.livefilestore.com/...008.JPG?psid=1

Must be Antigravity? Nah it's just stuck in a hole.

Cheers

[7imix]

Great work, farmhand!

[cody]

Ill have to do some testing to confirm what is going on in your capacitor, as im not positive why your voltage is so high. Your dual res link is correct but it is referring to a series tank circuit. Series tanks are fed from AC signals though, look at thier circuits, they are push pull, basicly AC square wave. Thats what i was talking about earlier about getting a higher voltage on the primary by getting it in tune. For whatever reason the solid state tesla coilers thought it was some great idea to actually tune the primary, something tesla was doing a long time ago . You can feed parallel tanks with pulsed DC but they dont have the voltage multiplication they have current multiplication.

Have you tried separating you coils any further yet? Find an old extension cord or something and see if it will go 50 or 100 feet, it might surprise you.

[Farmhand]

Ill have to do some testing to confirm what is going on in your capacitor, as im not positive why your voltage is so high. Your dual res link is correct but it is referring to a series tank circuit. Series tanks are fed from AC signals though, look at thier circuits, they are push pull, basicly AC square wave. Thats what i was talking about earlier about getting a higher voltage on the primary by getting it in tune. For whatever reason the solid state tesla coilers thought it was some great idea to actually tune the primary, something tesla was doing a long time ago . You can feed parallel tanks with pulsed DC but they dont have the voltage multiplication they have current multiplication.

Have you tried separating you coils any further yet? Find an old extension cord or something and see if it will go 50 or 100 feet, it might surprise you.

Yes I hope you can explain it because I am at a loss. I thought it would be current multiplying too. I worked out that the diode I have on the board does not serve the function of a de-Q-ing diode because the energy transfers back to the 470uf cap on the board, So I added another one at the inductor input without the de-Q-ing diode the input is much less but the effectiveness is also less (so thanks for that ). I still have a lot of things to try one being to increase the capacitance of the topload by adding a aluminium tube attached to the top disc but hanging inside the PVC. Just to see what happens.

I also want to try some longer Coil"B's", but I will have to set up a winding apparatus, I think I damaged the joint in my left thumb winding the others by hand.

What I did notice with the tank cap and the recovery waveform is that the waveform is centered on the screen and i have to raise the position to get the bottom to line up with the centre line.

Do you have an estimate of the cap size I should be able to fill to double the supply with a single bang ? I notice as I adjust the PW the cap voltage changes dramatically. If I reduce the PW the voltage can get quite high at the cap but the setup will only just make a CFL glow with less than 120Ma and there are point's in the tuning where the transfer to the receiver drops dramatically and the LED go's out. The LED is brightest with the narrowest PW I can get, 13us with this 0.01uf timing cap, which is promising.

My Bob Boyce transformer will output 40 volts from the secondary and I am using it single phase (three primaries at once) with a 2us PW 2us dead time producing a varible pulse number - pulse train then a pause, here is the waveform.

At the recovery diode, there are about 18 pulses in the group and it is adjustable down to a few and by increasing the frequency the screen can be filled.
http://public.bay.livefilestore.com/...001.JPG?psid=1

At the secondary.
http://public.bay.livefilestore.com/...007.JPG?psid=1

So i am wondering if I can use the control circuit to drive the transmitter I can close the pulse train on itself with frequency increase.

This is the gating oscilator I designed, it can have multiple CD4047's and drive multiple fets.
http://public.bay.livefilestore.com/...tor.jpg?psid=1

I'll gather some wire and try a distance test. I think the effect should be reduced in the bunkhouse here because it is all metal exterior if I go outside it should be better. I'll try it with a ground wire outside then I'll try it with a ground stake, I have earth stakes around here for electric fence's there are two about 40 meters apart. But I will have to secure the billy goat first.

Anther thing I notice is that I can get voltge reading from all the open ended coils around it and on the bench If I add a FWBR to the coils and measure the DC.

I would also like to construct a pair of smaller coils to see if they will receive from the big one at all, better than just a coil lying on the bench.

I'll start with the centre tube mod.

Cheers

[Farmhand]

Thanks for the compliment 7imix, it's fun though, I wish I had more resources.

This cap charge waveform is interesting. I think it could be the Magnetic collapse from the primary itself rebounding in the resonant circuit while the fet is off.

The field in the primary collapses and go's back and forth 1 time then ends up back in the cap just as the magnetic field of the charging inductor discharges into the cap and so the cap is charged an extra bit. Maybe
http://wv0v9q.bay.livefilestore.com/...005.JPG?psid=1

Anyway I made some tube's to add to the toroids.
http://wv0v9q.bay.livefilestore.com/y1pdAjoNoyGR6f5G8wTRiuJKb2hfd3fIA88n2ZQJ4AQ2Z-0o4CUhp-LzOZFdheQH3aY9KDmhS5RkIcZt-HRgPStzCwQ2kot__8c/Tube's%20002.JPG?psid=1

This is how I got the holes for the rivets right when I attached them. Also you can see by my hand how much oxidisation came off them when I sanded them clean.
http://wv0v9q.bay.livefilestore.com/y1pNk56priXgcOeUOlwh_K-1VKV8J8RETqADibAD7M0XSWBJQn5gR8yFb-nBzTiED2wXkoKsNm2LNtkdoimX_O16np_f_KVUC82/Tube's%20001.JPG?psid=1

They seem to be an improvement.

I will have to test tomorrow morning when the chickens are still caged. They will surely destroy this frail device.

[Farmhand]

OK so now I think I've found how to get better effect again by connecting the negative of the Primary/Tank cap to the positive of the battery instead of the negative, doing that lowers current draw from 125 Ma to 105 Ma with no observable reduction in light/output.

Here are the new waveforms which now fit on the screen.

Cap charge 10 v pd
http://v4j0ja.bay.livefilestore.com/y1p_It3f2U5cPNdpNBkBsfz_swVtvpW9Y1xX4bMhKgrBWGTfJe kLNV4IXOLP1vocFgejOR0dICPNpHyiEKT9xJzCllJfcVbvEvO/MT%20Wave's%20005.JPG?psid=1

Cap charge 100v pd
http://v4j0ja.bay.livefilestore.com/y1pNMkkOdeAP-9BxzL81Y8LU0vVIE2BOot4L8VTHg2IioQenV2twnreymh58sTG oXpCtZe7c5JPWOwk3F9RD8GeZx3yhEWEBpwB/MT%20Wave's%20004.JPG?psid=1

The charging inductor waveform then becomes this, which is downright pretty.
http://v4j0ja.bay.livefilestore.com/y1p8gPIdUfzH9sFLdA3o5Ofew2CC-NJaZl0mfgEld4hUQOp_Nf3mL5dQXDuURnu0vXZASm55pN-vbVpfSLzCF3CRa8rKEQvXeyK/MT%20Wave's%20006.JPG?psid=1

And this is the recovery waveform still not in use.
http://public.bay.livefilestore.com/y1pS1ua41_5gZfe4GN1WSQCXrrznkTRNRGxKNda0DUuXgk8t_0 LFl1JS6ia4SL9YM4nrKSGcldkpFh9OrzdprOPsw/MT%20Wave's%20008.JPG?psid=1

Not sure what to make of it all yet.

Cheers

P.S. I think I can sneak the primary circuit into resonance now with no ill affect, that should at least allow me operation at the maximum input voltage and least current.

[Farmhand]

This is what happens when I increase the PW a bit.
http://v4j0ja.bay.livefilestore.com/...004.JPG?psid=1

The cap get's a large leading edge.
And this is the hanging probe 350mm from the toroid.
http://v4j0ja.bay.livefilestore.com/...005.JPG?psid=1

Then if I increase the frequency a bit this is the hanging probe's form.
http://v4j0ja.bay.livefilestore.com/...009.JPG?psid=1

Then if I go a bit more of either this happens.
http://v4j0ja.bay.livefilestore.com/...006.JPG?psid=1

The protection neon fire's, indicating over 76 volts at the mosfet drain.
http://v4j0ja.bay.livefilestore.com/...010.JPG?psid=1

Then if I back it all off it looks like this on the hanging probe.
http://v4j0ja.bay.livefilestore.com/...011.JPG?psid=1

So that's telling me I need an IRF720 Mosfet or twenty. To have some real fun.

The inductor the cap and the Mosfet all get hot. Wow !

Cheers

[cody]

What is the mosfet you are using now?

[Farmhand]

What is the mosfet you are using now?

I'm using an IRF540 now, I just ordered some IRF740's and IRF840's, just in case.

I think i've done it. I changed out the oscillator timing capacitor from 0.01uf to 0.0026 uf, so now I can get from about 1us to 14 us pulse width and over 150Khz at minimum pulse width.

I can join up the wave and hey presto ! This is a hanging probe 300mm or 12inch's from the toroid.
http://v4j0ja.bay.livefilestore.com/...008.JPG?psid=1

I can do this with the minumum PW and up untill the voltage of the wave become's too much for the Mosfet. It can happen with 130 Ma and less. Or more.

By reducing the PW so much I have managed to get the Primary/Tank cap voltage level under control and can raise the cap voltage and therefore the output voltage at the receiver by increasing the pulse width to the next node where the wave is bigger than the last node. When adjusting the PW the output "drops out" then comes back up when the next node is reached with incresed voltage, just gotta find the right one.

Here is the tank cap waveform with a very narrow Pulse.
http://v4j0ja.bay.livefilestore.com/...009.JPG?psid=1

The light on the transmitter is brighter now when i put it there.
http://v4j0ja.bay.livefilestore.com/...005.JPG?psid=1

Looks good .

[Farmhand]

Hi Cody, This is one of the waveforms I get with this little scope by hanging the probe about 10 -12 inch's from the receiver toroid. THe transmitter one is similar but bigger and the spiky bit's are inverted to the receiver waveform.

The numbers don't mean much on the screen because of how it isn't connected.
http://v4j0ja.bay.livefilestore.com/...009.JPG?psid=1

I also noticed that by changing the time scale on the little scope I get to see a few different waveforms and different frequencies it can pick up most of the different wacveforms on the circuit.

And I also noticed that when tuned like this the inductor waveform go's to almost a flat line and instead of being hot it is cool to touch, the scope tells me there is just a smooth 12 volts DC flowing through the inductor.

Using only 160 to 220 Ma at 12.8 volts the transmitter can light a two foot 18 watt fluro in my hand quite brightly while the receiver lights 1 x 5mm white led with 47 ohm resistor and 4 x 3mm coloured ones with a 10 ohm resistor.

I think I have managed to get the primary circuit into resonance at I think 268.5 Khz and the secondary went into resonance with it kinda. I am getting all kinds of frequency readings but the gate says 268 Khz and the tank cap very similar.

Where should i measure it ? At the mosfet gate I guess.

I havn't done a transmission test over any distance yet because I want to be able to video it if it works and I wanted to get it working best as I can before i try.

Cheers

[Farmhand]

OK here's the circuit I am using. And I think the frequency I posted above is wrong I think it is actually half the 268 Khz I posted so more like 133 Khz.
http://v4j0ja.bay.livefilestore.com/...uit.jpg?psid=1

And I made a couple of 8 inch toroids from 2 inch flexable (slotted) drainage pipe.
http://v4j0ja.bay.livefilestore.com/...002.JPG?psid=1

I just ordered 320 meters of 0.5mm wire for another Coil not sure yet how I will make it yet.

Cheers

[Farmhand]

Hi all, I can now light a CFL from the receiver but only partly so far it does come on by itself though when connected.

This is using less than 200 Ma input to the transmitter to get this happening at the receiver about 4.5 meters away.
http://public.bay.livefilestore.com/...001.JPG?psid=1

The black wire on the ground is the ground wire, it is the only wire connected to the receiver.
http://v4j0ja.bay.livefilestore.com/...006.JPG?psid=1

I was messing about with different ways of using the output from the receiver when I blew my last 5mm white LED with a small neon triggered SCR cap discharger, so I decided I should discharge the cap through a Tesla coil primary (of course) to see if I could amplify the 70 volts charging the cap. And I seem to have done that.

This surprised me a little bit I must say.

So the next thing is to refine this receiver circuit to maximise the lighting of the CFL. Then I will have acheived something if I can do it at a greater distance. Outside I have insulated electric fence wire's I can de-energise and use for the ground wire or I can try the ground stakes. But considering I am only using about 200 Ma I think a actual ground connection may not work, more power would be needed for that I think, but who knows maybe not.

I'll make a sketch of the arrangement shortly.

Cheers

OK here is the receiver circuit I used, I will try to improve it when I've thought about it a bit.
http://public.bay.livefilestore.com/...003.JPG?psid=1

[Farmhand]

I couldn't resist these pics are the best lighting I've had so far. It's a 550mm tube 18 watts.

http://v4j0ja.bay.livefilestore.com/...002.JPG?psid=1

http://v4j0ja.bay.livefilestore.com/...005.JPG?psid=1

[7imix]

Nikola Tesla on his work with ... - Google Books

I found out that google books lets one preview the first 60 pages or so of "tesla on his work with alternating currents". If one clicks the "contents" button and clicks the figure on page 10, it shows various very interesting arraggements. I finally figured out that the coil with the funny squiggly line is a variable inductor.

Variable inductors and capacitors are going to be key for tuning. Unfortunately there are not good off the shelf parts available of the specs required.

Thanks for the idea of using a neon triggered scr to fire the cap into a tesla coil. I'm going to try that. I only wish there were an easy way to quench the discharge faster than the default scr behavior which waits for current to drop to zero. I have thought about using another free running oscillator circuit to turn on and off some heavy duty mosfets or even relays.