Tesla's "COIL FOR ELECTRO-MAGNETS".

[Magluvin]

As soon as you start talking of "Ideal" components you stray away from physical reality.

Why not just say an inductor with three Henries and 100 Ohms resistance ? The ideal voltage is OK because that can be pretty much made to happen in reality if there is sufficient DC resistance.

The ideal situation is so far from reality it is funny.

MileHigh can you do the sums for us to show the difference between your "ideal inductor" situation and a similar situation using an inductor with the three Henries and also with 100 Ohms DC resistance ?

Then with AC excitation or pulsed DC excitation (Alternating polarity pulsed DC or unipolarity pulsed DC) and tuned to minimum reactance with the 100 Ohms DC resistance. We can deduce that if the effect of the self induction is cancelled and the coil only faces the DC resistance the delay for the maximum current is practically negated. That is what the patent is about and that is basically the claims of the patent. Is it not ?

Cheers

P.S. I've said it before and I'll say it again, I have great respect for the knowledge you higher educated guys bring to the table. I can see your point in your example, but can you see the point I'm trying to make ? The coil is like a flywheel yes, but a flywheel has windage and bearing drag, a coil has DC resistance, it cannot be avoided and should not.
The patent talks of the DC resistance, the goal is to pass currents with no other significant opposition than the DC resistance. Lets see you do that with a flywheel !

At times it seems you almost try to provoke people to try to say they know more than they do, so that you can make them look bad or silly. Not saying you are trying to do that just that it seems that way at times. I do see where you are coming from. To me it seems like a sport to you, I and the others here are not your playthings, just sayin, just in case.

By all means debate is good but as far as I am concerned the debate is over the patent is explained. Not trying to brag but for an uneducated man in this field I think I hit the nail on the head with the turn spacing (self capacitor plate spacing or insulation thickness) meaning the voltage applied has to be considered, and differing voltages will produce different resonant frequencies because of that. Do you agree that insulation thickness or distance between conductors means different voltages will secure differing levels of self capacitance in a given coil ?



...

"The patent talks of the DC resistance, the goal is to pass currents with no other significant opposition than the DC resistance. Lets see you do that with a flywheel !"

Exactly!      "the goal is to pass currents with no other significant opposition than the DC resistance."   That is what Im going after. Im not looking for AC cycle functions nor cycle resonance Like MH implies that I do.  I had that idea a while back, but Ive deduced it to working with a portion of one cycle. All I want when the reed or transistor turns on is for the coil to avoid the inductive climb of the field till peak. So instead of when the switch goes on, there is a climb to peak, limited by resistance, of which is always there , there will be quicker build of the field. Not saying that more input wont be required. But I do know the difference between a bullet thrown at something and a bullet shot at something. Add up all the energy that I used to throw it as hard as I can and compare it to the energy the target received and there will be 'big' losses. Then compare the energy put out by the gun and compare the target again. Much better efficiency. Impact. Bruce Lee 1 inch punch vs picking them up and throwing them as far. If some motors today are near 90% efficient by picking up the armature and throwing it with a load, what might we get with the repeated 1 inch punch?

Imagine Lasersabers motor running at say 5v 1ua as seen in the vids. Now if we stacked, just for example, 30,000 of these motors together. Would there be good output at 5v 30ma??? This is another thing Im keeping in mind along the way.

I should have this motor going tomorrow and start winding the bifi bobbins on sunday.

Mags

[MileHigh]

Jbignes5:

It is just a bloody coil in the sense that a regular coil has some associated minuscule capacitance and the Tesla patented coil has somewhat more associated minuscule capacitance.  Normally "more minuscule" is still "minuscule" in the overall scheme of things.  It's more a question of shades of grey than anything else.  I am perfectly fine if you want to call it a cap/coil, but be aware that the inductance might be 10,000 times or even a million times the capacitance when equating Henries to Farads.  You must examine the relative proportions and try to draw some conclusions from that information.

For example, take a resistor in a circuit.  There is always inductance associated with a resistor.  However, under "typical" operating conditions you can ignore it.  In the case of the Rosemary Ainslie circuit, the conditions are not "typical" because of the high-frequencies associated with the MOSFET switching and you can't ignore the inductance in this case.

The capacitance will have a role in the operation of the cap/coil but only under certain conditions.  You can expect typical series or parallel LC type effects to take place, which in an of themselves are not remarkable but certainly worth exploring.  I am not sure specifically what you mean by the "phase" relationship between two coils in series.  You have to keep in mind that the current will be the same in both coils in series but the voltage certainly doesn't have to be the same.  But good luck and have fun investigating it.

Your 15 MHz bandwidth scope has enough bandwidth to do all sorts of experiments for sure.  You talk about a Joule Thief, on a Lawrence Tseung thread I gave the full flywheel-based mechanical equivalent "circuit" for a Joule Thief to illustrate how it can't possibly be a source of over unity in case you are curious.

You discuss putting a coil in oil or another medium to increase the capacitance and increase the breakdown strength of the dielectric.  Both statements are true.  However, preliminary analysis suggests increased capacitance is going to reduce your maximum voltage output.  Do you follow the rationale for that preliminary conclusion?  It's still possible that your stronger dielectric will "win out" and be more significant than the potential voltage snubbing effects of the increased capacitance, I don't know and it sounds like an interesting investigation.  You have to keep in mind that the current flow through the coil and the switching off speed will always be the two dominant variables that affect the output voltage.

See, now when you talk about coils being "polarized" you get into territory that can lead into heated debate.  In my entire life I have never heard of polarized coils.  So that might be your terminology.  Let's leave it at that for now.  I don't want to prejudge you or upset your test plans.  However, if a day comes where you do experiments and make clips where you discuss polarized coils, and I look at the clip and see you are completely off base, then I will tell you what I see and why I think you are off base.  Is that fair enough?

I just read further and you make reference to north and south faces of pancake coils.  So perhaps I misunderstood you and by "polarized" you just mean the field generated by the coil.  If that's the case ignore what I state above.

There should be no issues characterizing the output of a coil.  You can think of the discharge of the energy stored in a coil through a load resistor being kind of like a firecracker going off.  With a very high-value load resistance you get a very fast and energetic high-voltage "firecracker explosion" energy discharge.   With a very low-value load resistance you get a very slow burn low-voltage "firecracker explosion" that's very "mellow."  With a zero ohm load resistance and an ideal inductor the "firecracker" simply doesn't explode and retains its energy.

Please tell me Jbignes5 seriously, the business about the value value of the load resistance and the discharge speed and corresponding voltage - were you aware of that or had you ever heard of it?  I am really curious and I am asking you to be honest with me.

The crab pulsar video is very cool, I saw it several years ago and I read that it took a few years to "film."

Anyway, if you make a video with coils. there is a decent chance that I will be able to tell you exactly what is going on.  The real thing, and all that I ask is that you work to try to understand "my point of view."  I hope that's fair for you.

MileHigh

[MileHigh]

Magluvin:

Apology accepted.  I have never made a custom passive crossover for a speaker system.  But like any curious teenager I opened up various speakers and examined the crossovers and had somewhat of an inkling of what was going on.  Coils block high frequencies and let low frequencies pass and for caps it's vice-versa, one of the first things you learn when you read about audio.  During the disco era I worked for a sound and lighting company.  There were active crossover rack-mount modules that were programmable with plug-in cards.  They may have been made by JBL.  The cards had something like six sets of caps and resistors/inductors and I got the impression that the audio signal was run through six consecutive high pass filters that all did the same thing so that you ended up with a very sharp roll-off in the crossover, almost like a "step" functon.  If I am right I am still wondering how cycling the same analog audio signal through six consecutive filter stages did not cause any S/N issues.

I suspect the term "back EMF" comes from most people seeing a negative voltage spike on their scope when they first start experimenting.  If you switch your ground and signal scope leads around then you see that the negative spike all of a sudden becomes a positive spike.  As you know the coil is trying to keep the current flowing in the same direction, a kind of "let's keep going forward" EMF.

Too hard to make more than a few basic comments about the diode.  If you reverse the diode, you get the "fast firecracker explosion" effect.  The coil discharge will be short and fast and plow straight though the reversed diode and there is a good chance you will destroy the diode if there is enough energy available.

MileHigh

[MileHigh]

Farmhand and Magluvin:

Here is the real answer for the real-world inductor with internal resistance:

http://zone.ni.com/devzone/cda/ph/p/id/217

I tried to find a "friendly" link.  What you might notice is that at time t =0, the circuit acts _exactly_ like an ideal inductor.  As time goes on the resistive effects start to come into play and the current reaches an asymptote.

What's wrong with asking yourselves, "what would happen if there is no resistance" so that you can understand the pure effects of inductance without the complication and distraction of the resistance coming into play?  It's just being a Luddite to reject valid concepts that try to isolate the inductor from extraneous effects.  The goal is to try to understand how the inductor works, gain that insight, and then other aspects can fall into place.  It's anti-science and anti-learning to reject these ideas.

I can't think of a decent example but let's use audio.  When you listen to an old-fashioned LP record you insist on listening to a record with dirt and dust in the grooves and a scratch or two because that's the "real world."  You refuse to listen to a virgin dist-free record because that's not "real."  It's a sucky example but I think it makes the point a bit.

But then you have no problem with dealing with a pure voltage source with zero internal resistance because that's easy to relate to and you can understand that.  By the same token you are comfortable with a normal voltage source with some internal resistance.

How often do you guys worry about the series resistance in capacitors?  Not too often.  So you don't care about ignoring the resistance in capacitors, you are quite pleased to treat your capacitors as ideal capacitors most of the time and ignore the resistance.  But then the s*it hits the fan when someone dares suggest that you look at coils without resistance.

Going back to the real example, if you aren't familiar with the exponential function with the natural base of "e" as shown in the equations in the link, you should look it up if you want to advance your knowledge.  "e" = 2.7182818, Googling it would be a start.  The whole natural world (including electronics) revolves around this function.  The first derivative of e^x = e^x.  That means the nth derivative of e^x = e^x and the nth integral of e^x = e^x.  A capacitor discharges at a rate that is proportional to the current voltage in the capacitor.  So that means that a capacitor never fully discharges in the ideal sense, it just keeps on slowing down forever.  Same thing for an inductor, in theory it never fully discharges either.  It's all tied into e^x and the concept exists pretty much everywhere.

What is the ideal zero-resistance for the inductor example really showing you?  Well, you know when you push on the flywheel it's storing the energy from each push.  That's integration.  So the ideal inductor is performing the act of integration when you excite it with a constant DC voltage, or an AC voltage.  It integrates the voltage over time and the result of the integration is the energy storage in the inductor and the corresponding current flow.  So what you are really supposed to be thinking about when you consider an ideal inductor is the fact that it is an integrator of voltage.  By the same token a capacitor is an integrator of current.  Just like a flywheel is integrating and storing energy when you apply torque to it.

So all of these endless experiments about pulsing real-world coils with resistance all of a sudden don't seem so fantastical.  Every time you hit the coil with a short high-voltage pulse the coil just integrates on that pulse.  You are giving the coil a nudge and it slowly starts to roll, and current starts to fliow.  When I look at a scope shot of a coil being pulsed I can see the integration taking place on the screen.  But perhaps more importantly, I don't even need to see scope shot, I _know_ that the coil is going to integrate on the voltage pulses.  I can just look at the schematic.  There are no "fantastical effects" it's all pretty boring in a sense.  Coils and capacitors can perform both integration and derivation depending on what you are doing.  When in doubt, think of the flywheel.

Different voltages will not produce different resonant frequencies, period, and I am too tired to argue it.  Chew on what I said above for the hell of it.

I went off into the wild blue yonder in this posting but what the hell.

MileHigh

[MileHigh]

"The patent talks of the DC resistance, the goal is to pass currents with no other significant opposition than the DC resistance. Lets see you do that with a flywheel !"

I can do it with my eyes closed.

So you have a horizontal flywheel on a vertical shaft and the shaft is affixed to to a nice solid marble table.  Let's say the flywheel is made of granite and roughly the dimensions of a small tire, say 15 inches in diameter.

So you can spin the flywheel and watch it integrate your finger pushes.

Now, you take something that looks like a big watch spring and you mount it under the flywheel and connect one end of the spring to the table and the other end of the spring to the bottom of the flywheel.

Well, lo and behold, you have something that looks like a big watch spring movement.  Let's say that it resonates at about one cycle per second.

Sitting at the table with your beers and your spring + flywheel, you start make it oscillate just with a few fingers.  Slowly the amplitude of the resonance increases, and since the bearings are so good, the flywheel will happily resonate for five minutes or more before it stops.  (We know in the ideal case it will never actually stop.)

So, the boys have their beers and fiddle with the flywheel with their fingers.  Then Farmhand puts his finger on the oscillating flywheel and says, "Look Ma, just one finger!"   Farmhand doesn't do any real work with his finger, it just follows the oscillating flywheel at the resonant frequency.  With really good bearings and a really good spring with almost no hysteresis, he will barely have to expend any energy at all.  He could keep the flywheel oscillating all day just with his pinky if he wanted to.

What was that question?

"The patent talks of the DC resistance, the goal is to pass currents with no other significant opposition than the DC resistance. Lets see you do that with a flywheel !"

Note the instantaneous angular velocity of the flywheel corresponds to the current.

Meanwhile, Magluvin is now stymied about his "get out of jail free" card because he starts his experiment staring at a non-moving flywheel-spring combination.  The flywheel is not just going to magically start oscillating so that he can get his "free ride" to get his "instant current flow."  You have to put ENERGY into the flywheel-spring combination to get it to start resonating.  Note, in Magluvin's example he wants to get the flywheel to start turning without a spring.  He doesn't want the flywheel to resonate.  But in either case, spring or no spring, you start off with a stone cold dead flywheel that is not moving.  The only way to get it to start spinning or start resonating is to push on it and expend energy.  Intuitively, everybody knows that the flywheel is going resist any sudden movement.

So Magluvin just wants to get the flywheel instantly spinning - ain't gunna happen.  He is making the mistake of equating getting the flywheel spinning with no spring, to the case of the flywheel resonating with a spring where you have already put the energy into the system before the "start" of the experiment.

Note the spring only "appears out of nowhere" when you push the flywheel back and forth at a very high frequency (the self-resonance effects of the coil).  So we are talking apples and oranges like I have already stated.

MileHigh