Stefan's Tesla-Pages



For obvious reasons, this page is always
If there should be a bad link or if you know any other good Tesla-related links, send me an email (address is in the footer)!

Table of contents:

  Current projects I'm working on
  Further projects for the future

current projects I'm working on:
  • my website ;-)
  • build a housing for the AC-flyback
  • wattmeter
  • still searching for a wide place to fire all my bigger and bigger systems....
  • improving the Jacobs Ladder
  • display the electrodes of the violet wands => update the related web page, build an electrified demo inside my glass case for an old violet wand and some unique electrodes
  • make some measurements with the neon sign transformers

  • make some measurements with the inductive ballasts
  • make a silent (BIG DC filter caps) tube type TC using my beautyfull old Telefunken RS282 tube from WWII, I want to power my big 2000W-lightbulb with it as a plasma globe
  • build a housing for the DC-flyback
  • building the really heavy parts for my BIGcoil BlueThunder  (controll board, xfmr housing, primary, secondary, rotary gap...)

further projects for the future:

  • 4"-system / BlueThunder (10"):
  • make a motorized tuning coil for "online-tuning" of the primary
  • measure the small pigs
  • power-testing of big pigs

  • power-testing of small pigs

  • make solid mounts for the big toroids for my 4"/BIGcoil-secondaries

  • building an MMC for my 4"-coil
  • reduce the primary of the 4"-system (cut off the outer turns) or build a new one out of copper strap
  • make a better isolated support for the strike-rail of the 4"-system
  • vacuum gap for the 4"coils and blue thunder (BIG 35mm dia copper tubing, vacuum cleaner motor)
  • wind the BlueThunder-secondary (this will be the BIG TC, a man must build once in his life, read more about this here)
  • new BIG filterboard for my 4"/BlueThunder-systems (up to 1.25A@8kV capable of being driven up to 18kV which requires 3x16A/230V, that will be the limit for some years :-) )


  • organizing the GTL-Teslathons together with some other nice guys from the Orga-team
  • making a BPS-meter for static gaps with fiber optic (thank you Otto for the circuit plan and Toni for the fiber!)
  • Terry's TC-tuner
  • experimentation with different kinds of static spark gaps

  • build a measuring spark gap out of 2 of the old lamp spheres from the old living room
  • build a sphere terminal for Vitamini or 2"-system (1 lamp sphere from the old living room)
  • use lamp sphere from Peter for a ground terminal (strike point)

  • DC-charging through resistor => low BPS = single shot mode to get a voltage estimation from spark gap tables for single shots of pulses

  • micro-TC in plastic suitcase

  • Cascade (perhaps with sphere terminal)

  • single-shot-experiments (with HV/DC-source) to examine the dependence of spark geometry on the frequency of different TCs without being affected by the BPS and quenching behaviour (I'll use the same spark gap for all tests)

  • high power tube type TC with up to 3 tubes (GU81M) in parallel to achieve >2kW
  • take some measurements on my neons and the pigs
  • build a small Marx generator
  • build the coin shrinker / can crusher:
    measure all the caps
    - design power supply
    - design gap (relais + static gap)
    - arrange all items 
  • build a jacobs ladder with 50Hz sound resonance (electrodes inside transparent lambda/4-tube for a loud humming)

  • and a lot more....

My history in coiling:
2"-coil highschool project up to 1kW input power (but only a 2nF cap...) 0.13m 1986
2"-coil first really good coil 540W (635W) 0.36m (0.44m) 3'1997
4"-coil medium coil 2600W (only 30% of optimum capacitance) 1.43m (my current record) 8'1997
4"-coil medium coil 635W (matched = optimum capacitance) 0.7m 8'1997
1"-coil Vitamini 180W (only 50% of optimum capacitance) 0.115m 7'1998
two 1"-coils Vitamini (twin-configuration) 180W (only 50% of optimum capacitance) 0.115m 11'98
two 1"-coils Vitamini (twin-configuration) 180W (matched, MMC) >0.2m (getting even more
with a wider gap setting)
TTTC1 (2"-coil) tube: RS282 100-300W (silent sparks for plasma globes etc.) 0.05-0.33m Feb.'99-...
10"-coil BlueThunder 5kW (perhaps even up to 8kW possible) ~3m? still in the planning stage, nearly all parts collected
2"-coil improvements MMC, new HV-filter etc. ? 2000-2005
old secondaries some more tube coils:
GU81M (811/833)
150-1500W (silent sparks for plasma globes etc.) 0.05-0.5m somewhere in
the future

Other related data:

[links] (links to Tesla coil and high voltage related sites):
In this section of my pages, I try to honour most of the other coilers on the net, who helped me getting to this level of coiling by providing their excellent information. If some phrases and procedures described on my pages sound familiar to you, this is because I've stolen them from other pages or mails on various Tesla or high voltage related email lists. In all cases, this is only done because I couldn't say some things better in my words than yours. So please forgive me if I violated your copyright, it is only done for clearness. I tried to name all the original authors, but can't remember all. So if you should find something you have the copyright on, please drop me an email!

The Official Tesla Coil Screen Saver Contest:
From August 20, 1998, till October 14, 1998, Jerry Gore (Tesla Coil Madness) performed the official Tesla coil sceen saver contest. You can now download the winning images (combined inside the TCSS) from the screen saver page of Tesla Coil Madness.
PS: to get an idea of what you 'll find inside the TCSS, look at my title pic or my two other winning pics (pic2, pic3) :-)
PPS: good images need excellent bandwith - TCSS is 7MB...

Web Ring, Mailing Lists, Archives:

Some of the people (in alphabetical order) who greatly helped me getting to my current level of knowledge by discussing all the stuff excellently on the various mailing lists:

Literature and programs:

Some of the sites with links back to my site (can't name them all because I don't know all of them!):

FWM-statistics (February and March 1998):
Alone in the first two months I had the FWM-statistics running (February and March 1998), I had visitors from the following countries:
Austria (at), Australia (au), Brazil (br), Canada (ca), Switzerland (ch), Cyprus (cy), Rep. Czechoslovakia (cz), Germany (de), Danmark (dk), Finland (fi), France (fr), Greece (gr), Hungaria (hr), Malaysia (my), Netherlands (ne),  Norway (no), New Zealand (nz), Poland (pl), Portugal (pt), Sweden (se), Turkey (tr), Taiwan (tw), (ua), United Kingdom (uk), USA (us/edu/com/gov/mil) and South Africa (za).

A high number of the first 690 visitors came from highschools or other R&D-departments:

German highschools:
FH Aalen, RWTH-Aachen, FU Berlin, TU Berlin, Ruhr-Uni Bochum, Uni Duesseldorf, Uni Erlangen, Uni Halle, Uni Hamburg , TU Harburg, Uni Heidelberg, TU Ilmenau, Uni Leipzig, Uni Marburg, LRZ Muenchen (TUM), Uni Muenster, Uni Saarbruecken, Uni Stuttgart, Uni Tuebingen, Uni Ulm.
International education:
Adelaide (au), Berkeley, Caltech, Chalmers (se), Colorado, Goteborg (se), TU Graz (at), KTH, Uni Linz (at), Missouri, Ohio State, Oklahoma State, Pennsylvania, Stanford (SLAC), ETH Zuerich (ch). 
well-known companies:
Boeing, DASA, IBM, KfA Juelich, NASA, Siemens
and not to forget:
US Military, US Governement.

71% of the visitors used Netscape, 16% Microsofts Internet Explorer (I skipped other browsers as their number was to small).

eXTReMe Tracker (1)
I now have a new statistics running, the 'eXTReMe Tracker'. Much more information and more reliable. By clicking on the symbol on my TOC page, you can have a look at the complete data, it is public. Up to Dec. '98, Netscape had lost some percent and is now used by 55%, Microsofts Internet Explorer is used by 37% of my visitors ('other' browsers: 7%).

Over all, I had about 13 visitors per day (Jan. - Dec. 1998).

eXTReMe Tracker (2)
Up to March'99, 27% of my visitors came from Europe, 19% were form german speaking countries. With other words, 81% of my visitors don't speak german. That's the reason, my site is held mostly in english (I guess that most of the german speaking visitors understand english, too).

Netscape has lost one more percent and is now used by 54%, Microsofts Internet Explorer is used by 38% of my visitors.

eXTReMe Tracker (3)
At 27.10.00, I found out that the eXTReMe counter was resetted 188 days before (why the hell did they do this???) and has tracked 6184 visitors since then. This works out to 32hits/day during the last months.

I now (27.10.00) have 22416 visitors according to the S&P-counter.


Here are some fragments (anonymized to protect the privacy of the writers) of the feedback I got (no, I haven't gotten any negative feedback):

R. P. (Fri, 30 Jan 1998): Hello there. I just thought I would send you some email to tell you that you have a great page... I love the picture of you UNDERNEATH your machine on the index page.

D. C. (Mon, 09 Feb 1998): Hi! I've just found your page via the webring and I have to congratulate you! I think you've done a brilliant job, and it is in my opinion one of the best pages on this subject on the web, I shall certainly return to see it often. It has given me a lot to think about, but I will email you again soon, once I've had a good think.

S. P. (Tue, 10 Mar 1998): Your page on capacitors has convinced me to attempt to construct my own. Again, Thank you for your efforts in maintaining such well laid out website.

M. G. (Fri, 03 Apr 98): ... I started coiling this year, but I am not very successfull with my first system. I came accross your fantastic pages. It seems you are willing to share your knowledge... Thanks for the good work. I often read about the static gap, but could not get an idea on how to build it until I saw it on your page. The most useful site for me.

R. C. (Mon, 25 May 1998): Congratulations on your VERY informative web page. I do not have any electrical background but I found your site to be very helpful in understanding things a little better.... All the best in your projects - I'm curious about your luck with a small system - Who knows perhaps I'll build one!

S. B. (Wed, 27 May 1998): ...Zu deiner Homepage: Gratuliere, macht Spaß, deine Ausführungen zu lesen... Auf jedenfall ist es schön zu wissen, daß es doch auch einige Gleichgesinnte hier gibt.

A. S. (Sun, 31 May 1998): I am very impressed by your web site....

J. K. (Wed, 10 Jun 1998): FANTASTIC Tesla page....lots of good info on one page... As I'm sure you can relate to I am constatntly having to bounce between TESLA web sites to get info,tips,formulas...etc. Looks like you have combined all the info I will need all on one page.Good luck on your next coil.... and again GREAT JOB!

R. C. (Thu, 11 Jun .1998): ... You have a great web page. I wish it was around 2 years ago when I was building a coil then! Would have save a lot of searching in books etc. for formula. Anyway - I think my lack of info at the time was good because it only led to a better understanding of coils through having to research.

M. L. (Thu, 30 Jul. 1998): Nice well constructed site....

M. O. (Fri, 7 Aug. 1998): Best collection of info on the net. Thanks for your efforts!

R. B. (Fr. 28.Aug.1998): Sehr interessant und sehr ausführlich.

C. H. (Thu, 06. Oct. 1998): Your web page is really cool! Especially all the maths and useful stuff. I hate pages that only have photos. Keep up the good work!

J.L. (Mon.,12. Oct.98): Been looking for info on tesla coil basics for awhile. You have one of the best sites I have ever seen on Tesla Coils. Just wanted to say thanks for putting together such a good site. <SNIP> ... when I get a chance I try to increase my knowledge base of tesla coils. That is why your site was so exciting. A lot of info in one place.

OFK. (Sun.,24.Oct.98): war auf deiner Site: Suuuuuuuuuuuuuuuper ... (naechste mail 3h (!) spaeter:) ... mein Drucker rattert immer noch.

C. D. (Sat.07.Nov.98): Well done Stefan! Yours is without doubt the best TC site I have visited. In particular your details about the filter circuit was very useful to me...............I have wasted two NSTs so far, but number three is still holding up!!! Keep up the good work, Regards C. D.

T.B. (Sun.15.Nov.98): Overall, this has to be the best Tesla site so far (haven't gotten to them all). Seeing so much info accompanied by formulas, graphs and pictures sure does help. I'll have to capture it later so I can read it offline.

P.S. (Mon. 23.Nov. 98): Many thanks for your tesla coil page, it contained more information than all the other TC pages that I could find put together... Thank you for an inspiring page

J.C. (Wed.02.Dec.98): I must say your Tesla Coil page is one of the best I have seen... EVER! Well your page really is nice, very well organized.

A.H. (Wed.24.Feb.99): I've never seen such 'striking' photographs. Thanks for such great pictures. I had a great time looking at them.

F.S. (Fri.26.Feb.99): This is one of the best sites I have found, and greatly enjoy your scientific approach to your work, as opposed to some sites that seem to convey only empirical ideas for their builds. Keep up the good work!!! ... Great site !!!

M.S. (Tue.2.Mar.99): Hi! I just stumbled onto your page trying to get closer contact to Nicolai Tesla. It's really impressive compared to other ones I've seen, congratulations.

E.H. (Wed.7.Apr.99): Erst ein mal vielen Dank für die umfangreichen Infos, die ich auf Deiner Seite bekommen habe. Die Seite ist eine der besten, die ich auf meiner langen Suche gefunden habe (Ohne Schmarn !!)

C.D. (Mon.19.Apr.99): Hallo, Deine HP ist echt Super !

M.K.(Fr.25.Jun.99): Deine Seiten sind 1a ... !

G.H.(15.Aug.99): Congratulation for your website

M.S.(19.Aug.99): Hallo, nur mal 'ne kurze Mail als feedback. Ich finde die Seiten sehr gut gestaltet und vor allem die Bilder sind gut.

R.H.(5.Sept.99): ...das ist eine der besten Seiten, die mir zu diesem Thema untergekommen sind.

Elektor 9'99, S.67 (internationales Electronik- und Computermagazin): ... Aus der langen Liste (der Tesla-Trafo-sites im Internet) haben wir uns einige interessante Sites angesehen, die mehr als das übliche zu dem Thema bringen. Auf Stefans Tesla-Seiten wird der Aufbau eines Tesla-Trafos ausführlich beschrieben, außerdem findet man viele Diagramme, Tabellen und Formeln.

J. B.(9.Sept.99): Eine prima Website hast Du da zusammengebaut!

J. F.(23.Oct.99): JF Great website, very elaborate.


I stopped adding further feedback-mails at the end of Oct.'99 because I think there are enough of them posted here now  ;-)


By searching for my surname in the internet, I found some funny descriptions (at least funny for me as I haven't heard about the meaning of my surname in the american and english language before). Seems as there is more than one reason I have this surname (nomen est omen) :-) The main sources are the Jargon dictionary (at and a page from the University of Vaasa, Finland. Here is a summary of the textes:

/klooj/ [from the German `klug', clever; poss. related to Polish `klucza', a trick or hook] 1. /n./ A Rube Goldberg (or Heath Robinson) device, whether in hardware or software. (A long-ago "Datamation" article by Jackson Granholme said: "An ill-assorted collection of poorly matching parts, forming a distressing whole.") 2. /n./ A clever programming trick intended to solve a particular nasty case in an expedient, if not clear, manner. Often used to repair bugs. Often involves ad-hockery and verges on being a crock. In fact, the TMRC Dictionary defined `kludge' as "a crock that works". 3. /n./ Something that works for the wrong reason. 4. /vt./ To insert a kluge into a program. "I've kluged this routine to get around that weird bug, but there's probably a better way." 5. [WPI] /n./ A feature that is implemented in a rude manner.

Nowadays this term is often encountered in the variant spelling `kludge'. Reports from old farts are consistent that `kluge' was the original spelling, reported around computers as far back as the mid-1950s and, at that time, used exclusively of *hardware* kluges. In 1947, the "New York Folklore Quarterly" reported a classic shaggy-dog story `Murgatroyd the Kluge Maker' then current in the Armed Forces, in which a `kluge' was a complex and puzzling artifact with a trivial function. Other sources report that `kluge' was common Navy slang in the WWII era for any piece of electronics that worked well on shore but consistently failed at sea.

However, there is reason to believe this slang use may be a decade older. Several respondents have connected it to the brand name of a device called a "Kluge paper feeder" dating back at least to 1935, an adjunct to mechanical printing presses. Legend has it that the Kluge feeder was designed before small, cheap electric motors and control electronics; it relied on a fiendishly complex assortment of cams, belts, and linkages to both power and synchronize all its operations from one motive driveshaft. It was accordingly tempermental, subject to frequent breakdowns, and devilishly difficult to repair --- but oh, so clever! One traditional folk etymology of `kluge' makes it the name of a design engineer; in fact, `Kluge' is a surname in German, and the designer of the Kluge feeder may well have been the man behind this myth. There is in fact a Brandtjen & Kluge Inc., an old family business that manufactures printing equipment -- interestingly, their name is pronounced /kloo'gee/! Henry Brandtjen, president of the firm, told me (ESR, 1994) that his company was co-founded by his father and an engineer named Kluge /kloo'gee/, who built and co-designed the original Kluge automatic feeder in 1919. Mr. Brandtjen claims, however, that this was a *simple* device (with only four cams); he says he has no idea how the myth of its complexity took hold.

TMRC and the MIT hacker culture of the early '60s seems to have developed in a milieu that remembered and still used some WWII military slang (see also foobar). It seems likely that `kluge' came to MIT via alumni of the many military electronics projects that had been located in Cambridge (many in MIT's venerable Building 20, in which TMRC is also located) during the war.

The variant `kludge' was apparently popularized by the Datamation article mentioned above; it was titled "How to Design a Kludge" (February 1962, pp. 30, 31). This spelling was probably imported from Great Britain, where kludge has an independent history (though this fact was largely unknown to hackers on either side of the Atlantic before a mid-1993 debate in the Usenet group alt.folklore.computers over the First and Second Edition versions of this entry; everybody used to think kludge was just a mutation of kluge). It now appears that the British, having forgotten the etymology of their own `kludge' when `kluge' crossed the Atlantic, repaid the U.S. by lobbing the `kludge' orthography in the other direction and confusing their American cousins' spelling!

The result of this history is a tangle. Many younger U.S. hackers pronounce the word as /klooj/ but spell it, incorrectly for its meaning and pronunciation, as `kludge'. (Phonetically, consider huge, refuge, centrifuge, and deluge as opposed to sludge, judge, budge, and fudge. Whatever its failings in other areas, English spelling is perfectly consistent about this distinction.) British hackers mostly learned /kluhj/ orally, use it in a restricted negative sense and are at least consistent. European hackers have mostly learned the word from written American sources and tend to pronounce it /kluhj/ but use the wider American meaning!

Some observers consider this mess appropriate in view of the word's meaning.

By the way, I never met a native english speaking person (except the bilingual ones :-) ), who pronounced my surname the right way. So I will give some advice here: the 'u' is spoken /oo/, the 'ge' like it is in the word 'finger' (Klu-Ge). The german root of 'Kluge' is the word 'klug'. Its meaning is 'clever, smart, intelligent, clear-sighted'. Much friendlier meaning here in Germany than in other parts of the world :-)