RE: Newby

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Michael Brooks" <mbrooks-at-perrytech.edu> 

Perry is in Yakima, WA - about 2 hours southeast of Seattle

Michael Brooks
Instructor
Perry Technical Institute
mbrooks-at-perrytech.edu
509 453 0374 xtn 234


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, July 28, 2004 6:05 AM
To: tesla-at-pupman-dot-com
Subject: Re: Newby

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>


Welcome to the group.

BTW, what city and state is Perry in?

Dr. Resonance


  > Original poster: "Michael Brooks" <mbrooks-at-perrytech.edu>
  >
  > Thank you for the input; I am very interested in creating a little
  > monster of my own.
  > As far as my background I teach Electrical Technologies at Perry
  > Technical Institue. We train students for their Journeymen Electrical
  > License. I don't have any engineering background per se (though I am
  > working on that)
  > Primarily I teach basic theory behind caps, inductors, 1 & 3 phase AC
  > generation, sine wave characteristics, transformer theory and
  > connections, 3 phase power and PF correction.
  > Some of what I have read on the list so far is well beyond the
capacity
  > of my noodle at this point but I am confidant I can figure it out in
  > time.
  > Again I appreciate the information and I will continue to learn and
most
  > probably patronize with many questions!
  >
  >
  > Michael Brooks
  > Instructor
  > Perry Technical Institute
  > mbrooks-at-perrytech.edu
  > 509 453 0374 xtn 234
  >
  >
  > -----Original Message-----
  > From: Tesla list [mailto:tesla-at-pupman-dot-com]
  > Sent: Tuesday, July 27, 2004 12:08 PM
  > To: tesla-at-pupman-dot-com
  > Subject: Re: Newby
  >
  > Original poster: "Paul Nicholson" <paul-at-abelian.demon.co.uk>
  >
  > Michael Brooks wrote:
  >
  >   > I have just recently signed up for the list
  >
  > Great!
  >
  > Your description of power factor correction of an inductive load
  > is essentially the same thing as occurs when a coil is tuned to
  > some required frequency by adding capacitance at the top.
  >
  > If you picture a source of AC driving into the *top* of the coil,
  > (with coil base grounded) the source will see a lossy inductive load.
  >
  > (At least it will if the drive frequency is below the lowest self-
  > resonance of the coil).
  >
  > Then adding shunt capacitance (by way of the self capacitance of
  > a toroid or sphere) to the top of the coil is having the same
  > effect as power factor correction.   The PF correcting caps are
  > forming a parallel resonant circuit with the load inductance.
  >
  > However, this doesn't reflect the way that toroid sizes are chosen
  > when coils are designed.  Instead coilers (should) choose the
  > toroid (or whatever topload shape is employed) size that best suits
  > the generation of streamers  - if that's the intended application.
  >
  > They fit this chosen topload to the coil and then look for the
  > frequency at which the power factor correction naturally occurs,
  > ie the resonant frequency of the coil/topload combination.  So it
  > is kind of like the PF correcting process in reverse - start with
  > the cap and find the frequency at which correction occurs!
  >
  >   > Is this similar of the same as the calcs you may be using to
  >   > get to reasonance?
  >
  > Yes, when you've finished calculating the PF correction cap, you
  > should find it resonates at the line frequency with the load
  > inductance, ie Xc has the same value as the Xl of the load when
  > calculated at 60Hz.  In general,
  >
  >     (Xl = 2 * pi * Freq * L) = (Xc = 1/(2 * pi * Freq * C))
  >
  > which leads to Freq = 1/(2*pi*sqrt(L*C)).
  >
  > Welcome to the list Michael - and as you're obviously involved in
  > elec eng you won't have any trouble figuring it all out.  All the
  > usual laws of physics apply (with the odd subtlety to make life
  > interesting) so your existing EE knowledge applies 100%.
  > --
  > Paul Nicholson
  > --
  >
  >
  >