Use for the Tesla Switch

[ehsanco1062]

I see what your saying. Ya you have look at the direction and set your appropriately. Those diodes are to allow the computer to share a common ground with the transistors, while at the same time keep them Isolated.

Look at the diode drawing on them for the direction of the diode.
Same thing in the bridge rectifier if you build it.

Matt

[ehsanco1062]

And just start out with your batteries full. No worries.

Matt

Thank you Matt you are the man

Thanks
Ehsan

[citfta]

Ehsan,

Always follow the symbol on the diode. Do not worry about which way to turn it. Just turn it so that the diode symbol matches the way the diode symbol is shown on the drawing. And connect the bridge the same way. Match the symbols to the drawing.

Carroll

[ehsanco1062]

Ehsan,

Always follow the symbol on the diode. Do not worry about which way to turn it. Just turn it so that the diode symbol matches the way the diode symbol is shown on the drawing. And connect the bridge the same way. Match the symbols to the drawing.

Carroll

Thanks Carroll
Ehsan

[Turion]

For those of you who are interested in building one in the near future, here is the larger transformer Matt listed for us, disassembled and ready to be wrapped with wire. Sitting on top of it is one of the smaller transformers from Radio Shack that was on the list, already rewound and ready to go.

Matt, after having disassembled four of these now, and ONLY having put three of them back together, I have a real appreciation for what you're saying when you say you have built over twenty of these. I don't know whether to stand up and cheer, or call for the little men in white coats to take you away! My hat is certainly off to you. And I can only imagine what a giant pain in the butt an even bigger one will be. It's times like these I wish my kids were still young enough to be used as slave labor!

Anyway, got a couple leads on wire locally I need to go check out and if they don't pan out I will get mine ordered today. Could it be I'm putting off winding this thing as long as possible? Possibly!

David

[Matthew Jones]

I can do the big one in about an hour.

LOL

Once they have been taken apart it gets easier. You just pull out the bolts, slip out the small plates on the top and bottom. Pull a few "E" plates then put 2 bolts back in one side hold on and shake.

And it falls apart.

Putting back together is not that easy. The best thing to do is be drunk to the point you forgot how long you've stood there and done that.

Matt

[Turion]

Including the winding, that's gotta be at least a four six pack job!

[ren]

Here is a photo of my first Tesla Switch build.

I am using Arduino and HFS 30v 100A SSR's.

The re-assembled MOT has a MOT primary on the top and bottom @ 4 ohms, 150 millihenries, the middle MOT primary is from another model and thus reads slightly higher in resistance and inductance. So not ideal, but not too bad for not having to wind a thing. It will do for a first build. I already shorted the setup through the transformer manually and it fills a cap up nicely off the secondary.

Should have it up and running shortly.

Regards

[Sobakin]

The re-assembled MOT has a MOT primary on the top and bottom @ 4 ohms, 150 millihenries, the middle MOT primary is from another model and thus reads slightly higher in resistance and inductance. So not ideal, but not too bad for not having to wind a thing.

ren,
original MOT primary is for 110V or 220V input, so it have too many windings (even if this MOT designed to work in saturated mode) and, as You measured, too high resistance.
Why don't You rewind it with thicker wire (or several same wire but in parallel) - it'll be much more efficient.

About my experiments - now I've orderde 17AWG wire for winding transformer that can run at 50Hz, as both my transformers (small and bigger) wound for not less than 200Hz, and I have no more wire that thick enough.
At frequencies 200+ Hz there was no effect of switching, working time was worse than direct parallel battery connection to load independent of which batteries I use - small 1.3A-h SLA or bigger 4A-h flooded lead-acid

[Sobakin]

Here is formula for calculating optimal winding count for primary depending on section of transformer core and desired frequency of operation:

w = U * 2500 / (Sc * f * Bm),

where
U - input voltage (12V),
f = desired AC frequency (Hz),
Bm - induction of core material, for iron it's about 1 .. 1.2 Tl
Sc - area of section is a multiply of thicknesses of central part of transformer core (in which windings is), in cantimeters.

So we need two primaries each of w turns, and secondary w * 1.25 as say Matt, but if your system has less losses (by using MOSFETs instead of BJT or SSR and Shottky diodes in rectifier) it can be less coefficient, maybe 1.1 - 1.15, otherwise output voltage might be too high.
By knowing turns count, we may calculate wire width, thicker is better, but our winding must fit in transformer and we in our calculations may reserve about 30-35% for not ideal winding, better to have free space than not fit of all windings.

[Matthew Jones]

Does that math incorporate the magnetic field derived from a potential based system? How does 1 half of a dipole energize wire? In the same fashion as regular AC current?
Probably would be best just to leave those numbers alone for now, and just see what happens from there. But it might be better to sit around and wonder why things don't work.... I am sure those numbers won't tell ya. I'll tell ya right now it must be murder to know better.

Thats a nice build Ren.

One suggestion make sure you put some some big high voltage diodes across those relay's even if they are already incorporated into the relay. Those relays don't take to any transient behavior.

I can't wait to hear the results. Take your time and make sure you get it in tune before you start to measure.

Cheers Brother
Matt

[ren]

Does that math incorporate the magnetic field derived from a potential based system? How does 1 half of a dipole energize wire? In the same fashion as regular AC current?
Probably would be best just to leave those numbers alone for now, and just see what happens from there. But it might be better to sit around and wonder why things don't work.... I am sure those numbers won't tell ya. I'll tell ya right now it must be murder to know better.

Thats a nice build Ren.

One suggestion make sure you put some some big high voltage diodes across those relay's even if they are already incorporated into the relay. Those relays don't take to any transient behavior.

I can't wait to hear the results. Take your time and make sure you get it in tune before you start to measure.

Cheers Brother
Matt

Thanks Matt,

I originally wondered why you chose to place the switches like that, I thought that maybe you placed them where you did in an attempt to isolate the switches somewhat from the inductors. But, as we know, that spike will find his way around your circuit till he pops something.

So 1n5408 (?) will do, in reverse over the +/- terminals, or do you need something higher in current or speed?

Cheers

Ren

[Sobakin]

Does that math incorporate the magnetic field derived from a potential based system?

Matt, I posted this simple math, which is from classic transformer theory, since didn't find here any another, I though we need some point to start from.
I think that too much of wire is not good, if You're not agree - please say why and provide your variants, even if it not scientific.
I want You to write a bit more, I feel You have what to say, or are You just waiting for something?
Can You descript your working transformers more detailed - core size (section area), count of windings and working frequencies?
Maybe I put attention not to major things, but it's becauce I don't know which of things is really significant for high effecience.
I spend time generally not in typing posts but really try different combintions of transformers, batteries, loads, switches, frequencies, duty cycles etc, but still didn't try frequencies lower than 150 Hz with your scheme, as don't have yet a transformer capable to run at such low frequencies, I read what yours run well at 50-60Hz.
I've read in Panacea's report that You have good results with 6-switch TS's even with mechanical system (did You hav same results with 6-switch solid-state?), but my results still not good

[Matthew Jones]

Thanks Matt,

I originally wondered why you chose to place the switches like that, I thought that maybe you placed them where you did in an attempt to isolate the switches somewhat from the inductors. But, as we know, that spike will find his way around your circuit till he pops something.
So 1n5408 (?) will do, in reverse over the +/- terminals, or do you need something higher in current or speed?
Cheers
Ren

Ya that will do. Its just "Incase" thing. Like I said the Hong fa's are very temperamental. They won't put up with much. You might run that thing 100 times then POW, no switch. I have used them alot.

Matt, I posted this simple math, which is from classic transformer theory, since didn't find here any another, I though we need some point to start from.
I think that too much of wire is not good, if You're not agree - please say why and provide your variants, even if it not scientific.
I want You to write a bit more, I feel You have what to say, or are You just waiting for something?
Can You descript your working transformers more detailed - core size (section area), count of windings and working frequencies?
Maybe I put attention not to major things, but it's becauce I don't know which of things is really significant for high effecience.
I spend time generally not in typing posts but really try different combintions of transformers, batteries, loads, switches, frequencies, duty cycles etc, but still didn't try frequencies lower than 150 Hz with your scheme, as don't have yet a transformer capable to run at such low frequencies, I read what yours run well at 50-60Hz.
I've read in Panacea's report that You have good results with 6-switch TS's even with mechanical system (did You hav same results with 6-switch solid-state?), but my results still not good

I gave you recipe. I told you what to look for. I told you the speeds. Other peoples are working. So far yours hasn't and now you want to give advice.
Based on past experience that behavior is very suspect to me. I am hoping you are not that way but I would really appreciate you more if had you tried first what I told you to use and not what you felt was better.
"Iron just wont run at these frequencies" Was along the lines of what you said.
So I do not understand why now you want help and explanation. Isolate your problem and then I can help you.

Matt

[dnewkirk]

DEN's Small TS data.pdf