Re: Concerning Peter's DC Drive

From: 	richard hull[SMTP:rhull-at-richmond.infi-dot-net]
Sent: 	Thursday, July 17, 1997 1:18 PM
To: 	Tesla List
Subject: 	Re: Concerning Peter's DC Drive

At 12:08 AM 7/17/97 -0500, you wrote:
>From: 	Larry Robertson[SMTP:LWRobertson-at-msn-dot-com]
>Sent: 	Wednesday, July 16, 1997 8:22 PM
>To: 	Tesla Builders
>Subject: 	Concerning Peter's DC Drive
>Hi Folks
>I also have been thinking for a while that a DC drive would
>be not only more efficient, but would also make the rotary gap
>completely uncritical as to speed, up to maximum power delivery.
>As I was contemplating on how to get the small resonance cap.
>recharged, I thought that we use a pulse discharge already,
>so why not pulse charge it as well. If the large cap is big
>enough compared to the small cap., having them in series from
>the point of view of the primary coil should not change the
>resonant frequency much. For instance, if the small cap is
>0.02 uf and the storage cap is 1 uf, when viewed in series
>the capacitance is 0.0196, not much of a difference.
>The diagram below might actually be legible if viewed with
>a monospaced font, such as "QuickType Mono" which I used to
>make it. 
>Think about a rotary gap consisting of two poles rotating,
>and four poles stationary. Two adjacent stationary poles are
>connected together, and go to the resonance cap. The other
>side of the resonance cap goes to one side of the primary
>coil, the other side of the primary goes to a common which
>I'll call ground. The two remaining stationary poles go to
>the HV end of the storage cap, and to ground, respectively.
>As the gap rotates, the resonance cap will be alternately
>charged from the storage cap, and shorted to ground. The
>primary coil will alternately see the small cap and large
>cap in series with it, then just the small cap in series,
>but with opposite polarity. 
>                                   Rotary
>                                      ------ 
>                                      v     |  Small
>     + ------ RFC---------o-------->     <--o-  CAP ----
>>From                      |           ^                 |
>Diode                   Large         |              Primary
>Bridge                   CAP          |                Coil
>                          |           |                 |
>     - -------RFC---------o-----------o-----------------
>I think a diode bridge would make most efficient use of the
>I've already built one diode, consisting of 35 1N5408  3 amp
>kV diodes in series, each one with a 1 meg. resistor and a
>0.001 uf cap across it for equalization. I put all these
>on a piece of plexi, and covered it in mineral oil in a
>Tupperware container.
>It takes the output from two 60 ma 15kv neons in parallel
>with no complaint, but I still need a storage cap. A
>suitable resistor between the diode bridge and the RFC's
>might also be a good idea.
>What do you think?

Tesla actually utilized this idea sometime prior to 1899 and actually gave a
diagram in the CSL for this arc charging of the resonant capacitor.  I do a
similar thing in my small magnifier #12 with hydrogen thyratron switching.
There is no idea in this area new under the sun, but new technology just
allows the old ideas to be done with a bit more efficiency.  With Tesla's
system of 1899, he gave the idea a C- grade after testing it out.

Richard Hull, TCBOR