In regards to your Tesla car article at http://www.fourwinds10.com/siterun_data/science_technology/new_technologies_and_inventions/news.php?q=1244824985

find enclosed a zip of various information I've saved on this topic over the years.

While I'm happy to accept that the fundamental story of Tesla's electric car is true, and Tesla really did achieve a tap of some limitless source of power, unfortunately there's effectively zero useful information on how he did it. In the public domain anyway. Who knows what was in the many cases of Tesla's writings from his later years, that have been taken away by 'men in black' in various incidents.

We are left with stories such as his nephiew's tale - and it's many retellings and elaborations by others. Here are a few comments of mine on these stories.

* The two diagrams in your current article date, as they say, from 1993. However they have had their original attribution erased. See the file TESLAFE2.HTM in my attachment, and the images TESLAFE1.GIF, TESLAFE2.GIF, which I'd saved in 2000. Same diagrams, but with the original "KeelyNet BBS" with postal and phone numbers. They were produced by Jerry W. Decker of KeelyNet, to go with his commentary in TESLAFE2.HTM

We don't know who erased that attribution, however we do know 'Andy Janson' didn't create the images. Note that this is not admitted. Someone somewhere in the chain is not being honest.

* As for Jerry W. Decker's commentary and diagrams, there are several important details.

Firstly, keep in mind he's totally making this up, which he admits. He is guessing, based on the very few details from the original story. Of which there are multiple versions, conflicting in many of the critical details. So now we must consider the quality of Mr Decker's technical guessing skills. Some observations:

 - He includes two 'diodes' in his diagram. This is a serious flaw, since in Tesla's time there was no such thing. Semiconductors weren't invented for decades after, and then it was decades more before semiconductor rectifiers (diodes) could handle much in the way of current. In Tesla's time rectification could only be done with vacuum valves (which is where the word 'diode' - 'two elements', cathode and plate comes from.) There were also very bulky and lossy copper oxide plate rectifiers - but I'm not sure if they weren't invented till later as well. In either case, valves or plate rectifiers, neither one at that time could handle much in the way of current.

 - Mr Decker states: "We have no specifications for the AC motor that Tesla used in the auto, so we have no idea if it was single or polyphase." This is true - I can't find in any of the versions of the tale, any mention of a very critical detail. Were there two cables to the motor, or three? If two, it was a single phase motoer, that had to either have a commutator (but one account says it was brushless), or a shaded-pole induction motor - but those are really quite inefficient and unsuitable for high power, or a two phase motor with very bulky phase shifting capacitors - most unlikely given the absense of any mention of huge capacitors next to the motor, and that I don't think such capacitors could be made at that date anyway.

Given that Tesla's greatest _adopted_ invention was three phase power (and motors), and these are very efficient, it's most likely this motor was three phase. But that requires three wires minimum (Delta-wound), or four (Y-wound.)  So on this one we just don't know.

The saddest thing about Mr Decker's text though, is this: "In the case of a single phase motor, it only requires a single winding which projects a magnetic field that rotates according to the increase or decrease of the alternating current. A polyphase (poly = two or more) motor uses multiple windings which are fed by phased input currents that alternate in such a manner as to reinforce each other. In the case of a 3 phase motor, the currents are phased 120 degrees apart. This gives much greater torque to the motor but requires 3 times the current because it uses 3 times the input energy."

A paragraph in which Mr Decker reveals he knows nothing about AC power engineering, by making one utterly false statement, and at least two serious misconceptions. Three-phase motors do NOT require "3 times the input energy." Actually they are _more_ efficient than single phase AC motors. Summing the power of the three input phases gives a total less than the power on the one input of an equivalently loaded single phase motor. The rest of his description is flakey too. "in such a manner as to reinforce each other" is just plain wrong. No, they simply result in an overall field within the stator that rotates. The field from any individual phase winding is no more or less 'strong' than it would be without the other phases. "... a magnetic field that rotates according to the increase or decrease of the alternating current" is simply garbage. 'Single phase' AC motors must always have at least two 'windings' angled apart to produce the essential rotating magnetic field. Just in s!

 ome, t

he second phase is derived via a phase-shifting capacitor, while in 'shaded pole' motors it's derived in the motors magnetic poles by placing a heavy copper 'shorted turn' winding around an offset pole of the magnet yoke. This retards the magnetic field in that pole, hence producing rotation relative to the unretarded pole.

Anyway, it doesn't really matter. Mr Decker made clear at the outset that he's merely speculating. From the points above and other details of his article, I conclude his speculation is worthless, and adds nothing but more confusion to the story of Tesla's electric car. That can't be helped. What I do have a problem with, is where Decker's ideas resurface without the original provisos, and start to blend into the original legend. For instance your article states the diagrams "purport to be similar to the circuits that Nikola Tesla is said to have used." No they don't, and that's very important to keep in mind.

Regarding the vacuum tubes said to have been used - there are two versions:

"12 Vacuum Tubes (70L7-GT rectifier beam power tubes)"

"contained 12 vacuum tubes, of which three were of the 70-L-7 type"

So were they all 70L7, or just three of them? Who knows?

Here's some information on that tube type. Not that it helps particularly.

http://www.tubebbs.com/tubedata/sheets/093/7/70L7GT.pdf

http://www.radiomuseum.org/tubes/tube_70l7.html

The electric car events happened in 1931. It's perhaps significant that in Tesla's prolific output of around 300 patents, the last known one was issued Jan 1928. (See http://en.wikipedia.org/wiki/List_of_Tesla_patents and http://en.wikipedia.org/wiki/Nikola_Tesla )

Tesla lived 1856 to 1943. In http://en.wikipedia.org/wiki/Wardenclyffe_Tower you can see that in the period from 1895 to 1905 Tesla suffered traumatic setbacks. A fire destroyed his laboratory, most equipment and notes. Then his Wardenclyffe Tower project was terminated, and eventually destroyed. My guess is that during this period the financiers were realising that Tesla's inventions threatened the 'order' of the world (ie their control of it) and were starting to take steps to rein him in. He was never again able to establish a stable, well funded laboratory environment. Hence the 'on the fly' nature of his construction of the 'box' for the electric car, and his extreme secrecy about how it worked. It would also explain his choice of a small, fairly obscure car manufacturing company to fit the motor. Not to mention their rapidly ceasing to exist soon after, once news of his efforts started to spread among 'interested' parties. Wardenclyffe all over again.

In any case, the dates suggest a story. Sometime around 1928, Tesla had a really good idea. Developing it took up all his time, sufficiently to put an end to his usual steady output of assorted patents. This idea was something he knew he had to keep quiet about, given what happened at Wardenclyffe. He found a car company he felt he could trust, and by 1931 was ready for a practical test. Unfortunately, word did get out, and from that time on he was under serious attack, with all attempts to commercialise his latest invention blocked. By this time he'd be a terribly embittered man. He never applied for another patent, and spent his remaining years living in hotels, moving on when unable to pay the bills. Perhaps he described his 'free electric power' invention in his later notes and diaries. Perhaps he was so embittered by his treatment that he didn't. The only people who know, are the 'men in black' who took away all his known writings shortly after his death, and to this da!

 y mana

ge to 'vanish' any other lost Tesla notebooks that turn up.

Regards,

TH