[TCML] 5" Sparks - Approx 35 watts input power: Tesla was correct!
electrotherapy at hotmail.com
Wed Mar 12 14:16:36 MST 2008
This is definately an air-core resonant Tesla Coil...it is insulated in wax, technically, but is 100% a TESLA Coil and not an IGNITION or induction coil in any way. The only thing different is the shape, they are flat. The secondary coils contain 3600 turns of wire in the secondaries, and 24 3/4 turns of wire in the primaries. It seems like a peculiar ratio, but in reality was a classic form of Tesla Coilthroughout the teens and 20s. The resonant frequency is something like 40 kHz, I'll give the complete coil specs and let someone elsedo the math. [I'm lousy at formulas, just a crude machinist and not a mathemetician :)]. Maybe Bart can run it through JavaTC.
The windings of the secondary coils are multilayered in beeswax, identical concept to the Tesla table top models. The primary winding is also embedded in wax to prevent arcing to it from the centers of the secondary coils. I will add some photo links in an additional post.
The break rate for the coil is high, I am unsure yet exactly how high but I imagine around 150 - 300 BPS. Its a similar interrupter used for induction coils and the like, vibrating copper spring with some tungsten contacts. The kicking coil circuit is indentical to a normal Tesla coil circuit except there is no "primary" for the transformer. The electromagnet simply turns itself on and off, the self-induction during the "break" charges a cap and discharges it through the interrupter points to the Tesla Coil - just like charging a cap in parallel and discharging it in series with the primary of a Tesla Coil. The voltage is normally limited to under 1000 volts using this method, but it has the advantage of not consuming a lot of current. This was a typical design back in the days when house current could be AC or DC andthis circuit works well on either.
If you've seen the little Science First or Edmund's Scientific Tesla Coil it is the same principle, only using flat coils instead of a conical coil.
Gary, I haven't measured the actual current yet in a precise manner. This Violet Ray doesn't have a current rating on the name plate, but most of them are 15 - 50 watts, the majority (75%) being around 30 watts. I have some analogue meters I will have to try. On shorting the electromagnet, it draws about 50 watts. The real power consumed though is less, because the coil is only in the circuit part of the time, as the interrupter actually cuts the power from the mains.
The electromagnet I want to build will have a large core and a large number of windings. I know from past experimenting, that an oversized coil that doesn't consume a lot of power will produce a nice high voltage arc when you break the circuit. Tesla's coils had huge electromagnets which explain to some extent the success of his design - high voltage with little current consumed. Violet Rays weren't made for efficiency as much as convenience (and compactness for the quack trades), but the fact that all things considered 5" sparks were being generated with something conjured up out of old Tesla coil components using a relatively small amount of power. If more thought and engineering went into the peculiar design, Tesla's claims of efficiency don't seem too far off.
I have some original plans of several of the electromagnets that Tesla used. I received a photograph of a page of his notes "off record". I will build these and document them on the site and test them in the same circuit.This evening I'll try and put some concise photos of the whole setup I did last night, with closeup photos of the coils/components, etc.
> From: pterren at iinet.net.au> To: tesla at pupman.com> Subject: Re: [TCML] 5" Sparks - Approx 35 watts input power: Tesla was correct!> Date: Wed, 12 Mar 2008 20:47:59 +0900> CC: > > About 40 years ago I was driving twin antiparallel ignition coils from a 12V > 1A through a multivibrator to get perhaps 1 inch sparks. Ie 12 watts per > inch. You are getting 7 watts per inch. No problem with that. The break > rate will determine the power but not the spark length. Drop your break rate > down to 1Hz and your spark length stays the same but power drops to perhaps > only a few watts.> > I think people were thinking that you were talking about a "Tesla coil" ie > air cored resonant HV transformer. With a TC, "Break rates" and hence power > are likely to be perhaps 10 times higher higher than a multivibrator > (guessing here), hence power drawn will be 10 times greater. Spark length > tends to be more as a consequence of spark growth than voltage (hence you > see streamers with a TC but not your type of kicker setup).> I suspect "a few people considered this an unrealistic request" were > comparing apples and oranges.> Nice setup BTW.> http://tesladownunder.com/Tesla_spectroscopy1.JPG> > Peter> > > > ----- Original Message ----- > From: "Jeff Behary" <electrotherapy at hotmail.com>> > Hey All,> A while back I posted a request to try and replicate Tesla's table top > oscillator that he claimedgave 6" sparks with less than 35 watts of input > power. I think a few people considered this anunrealistic request.> > Jeff Behary> The Turn Of The Century Electrotherapy Museum> _______________________________________________> Tesla mailing list> Tesla at www.pupman.com> http://www.pupman.com/mailman/listinfo/tesla
Need to know the score, the latest news, or you need your Hotmail®-get your "fix".
More information about the Tesla