Re: Charging inductors for resonant charging

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Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

Very, very clever... I like it!
One could make a very sophsticated system if one wanted, and you'd be
working at "reasonable" voltages
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, January 31, 2004 10:25 AM
Subject: Re: Charging inductors for resonant charging


 > Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net>
 >
 > Ed, Jim and all,
 >
 > Here's an idea I was kicking around with Ed Wingate a while back. You
could
 > simply use another distribution transformer and ballast as a HV charging
 > inductor. Use the HV winding in series as the charging inductor. Connect
 > the low voltage side of the DT to high current ballast (welder or
 > adjustable high current inductive ballast). The DT will multiply the LV
 > side ballast inductance by its turns ratio squared, easily making the HV
 > side look like a large, adjustable, HV inductor. And a properly sized DT
 > already has the necessary BIL and current rating required.
 >
 > By selecting the proper distribution transformer and ballast, you should
be
 > able to get almost infinite flexibility with without the need to resort to
 > a custom HV choke.
 >
 > Best regards,
 >
 > -- Bert --
 > --
 > --------------------------------------------------------------------
 > We specialize in UNIQUE items! Coins shrunk by Ultrastrong Fields,
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 >
 > Tesla list wrote:
 >
 > >Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 > >Tesla list wrote:
 > >  >
 > >  > Original poster: Jim Lux <jimlux-at-earthlink-dot-net>
 > >  >
 > >  > At 08:01 AM 1/29/2004 -0700, you wrote:
 > >  > >Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 > >  > >Tesla list wrote:
 > >  > > >
 > >  > > > Original poster: Jim Lux <jimlux-at-earthlink-dot-net>
 > >  > > >
 > >  > > > What sort of sources are there for a 5-15 Henry charging inductor
 > > for a
 > >  > > > resonant charging circuit? RMS current would be in the 1-2 Amp
range.
 > >  > > >
 > >  > > > Is this a "wind it on a MOT core" kind of thing?
 > >  > >
 > >  > >         I'm no a magnetics designer but that sounds like a HUGE
 > > device to me!
 > >  > >If the charging frequency was 120 Hz the reactance of the 5 henry
choke
 > >  > >would be about 3770 ohms and the voltage across it at 1 amp would
then
 > >  > >be 3770 volts.  If it is to pass 1 amp the wire size would probably
have
 > >  > >to be around #22 even for intermittent operation, and the resulting
wire
 > >  > >area would require a large core.  Real designers step forward?
 > >  >
 > >  > So then, what ARE people using for charging chokes in resonant
charging
 > >  > systems..
 > >     Large inductors; maybe someone here can help.  I have one or two
 > >charging chokes used for a 250 watt average power radar modulator and
 > >they're about as big as an MOT.  I don't remember the ratings but have
 > >saved them for many years with the idea of using them in a resonant
 > >charging circuit for a "DC TC".  I have a 7500 volt 60 Hz power
 > >transformer out of an old Navy radar and intended to rectify it and use
 > >resonant charging along with an RSG.  Like many other projects it has
 > >yet to get off the ground.
 > >     Maybe I've misinterpreted what you wrote.  I'm used to thinking in
 > >terms of average DC current, peak operating voltage, and frequency.  I
 > >just dug out "Volume 5" (Glascoe and Lebacqz) and in Figure 9-13, page
 > >375, they show samples of various DC charging inductors.  The biggest
 > >one in the picture is rated at 0.4 amps, 17 kV peak, and has an
 > >inductance of 19 henries; it weighs 71-1/2 pounds and is potted in a can
 > >which looks like about a 7" cube.  You seem to want something over twice
 > >as big.  There's a whole chapter of the book devoted to "charging
 > >circuits for line-type pulsers" of which I'd say a TC is a degenerate
 > >case.  There is some information on "THE DESIGN OF D-C CHARGING
 > >REACTORS".  Almost the first sentence reads "Reactor design is usually
 > >based on experience.  However, in the absence of suitable previous
 > >experiende the design process can be started mathematically."  Design
 > >equations and discussion follow, which don't look too horrid.  About
 > >four pages of stuff which I could copy and send you if you're
 > >interested.  I notice that the magnetic units are ampere turns/in (not
 > >so bad) and flux is expressed in "lines" (lines/square inch).  The work
 > >described was started about 1942, the same year I started in engineering
 > >school, and apparently the authors had studied the same system of units
 > >as some of my instructors.  We had so many different systems of units
 > >(english, cgs, MKS, MKS rationalized, etc.) thrown at us that I've been
 > >perpetually confused.
 > >     I suspect your reactor could be wound on the core of a transformer
 > >weighing of the order of 100 pounds or so, and if memory serves me right
 > >small pole pigs fit into that class.  Someone who owns some might
 > >correct me.  In the "good old days", here in the Los Angeles are it was
 > >possible to go to the Edison Company salvage yard in Alhambra and pick
 > >up small (unpotted) pole pigs for free.  2200 volt to 110 volt units
 > >were good for plate transformers for ham transmitters and I suspect
 > >there are some of them still around.
 > >Ed
 > >
 > >.
 >
 >
 >
 >
 >