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An article in the May 1919 issue of the Electrical Experimenter, "The True Wireless," talks about a "rotating brush wireless detector" that Tesla used, and in the January 1919 issue there is a photo of a device identified as "Tesla's Static Eliminator." Do you have any knowledge of these devices?
The "rotating brush wireless detector" was one of a broad array of experimental single terminal vacuum tubes designed to be operated in conjunction with one of Tesla's high-voltage power supplies. The construction of the tube itself was very similar to the now popular "plasma globe" novelty item. In one form it consisted of a glass globe in the neck of which was sealed a glass tube. The end of the tube was blown out to form a small sphere positioned at the center of the larger globe. The connection to the power supply was made through a moderately rarified, highly conducting gas enclosed within the central tube. You can learn more about this specialized vacuum tube, the rotating brush phenomenon, and other types of single electrode tubes in Tesla's lecture "Experiments with Alternate Currents of High Potential and High Frequency" which appears in the book Inventions Researches and Writings of Nikola Tesla. The actual description, with illustrations, appears on pages 226-230.
Regarding Tesla's static eliminator, as you have discovered, there is relatively little info available about this dinner-plate size device. It was a variable coupling RF transformer consisting of two flat spiral or pancake coils. The uppermost coil could be raised on a vertical central column and locked in place above the lower coil at the desired separation. Tesla spoke about the static eliminator in a 1916 interview (see Nikola Tesla On His Work With Alternating Currents) saying,
By the way, both of the Electrical Experimenter articles can be found in the book Solutions to Tesla's Secrets.
If the static eliminator
received a patent, it must have been issued
by a country other than the United States. Nevertheless, it is not
included in the partial list of patents published in the CATALOGUE OF TESLA PATENTS,
Belgrade, 1987. Using data found in
this list and other sources [1,2,3], it is apparent there were at
patents issued to Tesla in 25 countries over the course of his lifetime.
This figure breaks down as follows:
Number of Patents Listed
|Actual Number Found|
|Great Britain||16||22 (+6)|
|New South Wales||2|
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