Re: deceptive transformer

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 4 Apr 2004, at 17:41, Tesla list wrote:

 > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
 >
 > I seem to remember 90 hz being popular for AC b4 tesla invented his
 > motors, which needed the slower 60 hz. As for ferrite pigs...ever seen
 > a Balun? Its a transformer that works at HV HF to convert a balanced
 > line to an unbalanced line or vice a versa. Ferrite cores.
 >
 > ---Eric

AFAIK 50/60Hz was chosen mainly for good transmission efficiency.
Less skin effect at 60Hz means one can beneficially use larger x-
sectional area conductors. Other factors may have included the
reduction in transmission line effects since the grid transports
power over rather large distances. Another possible benefit is that
of reduced parasitic energy coupling into structures near powerlines.
Tradeoffs for lower frequency running include tansformer core size
having to increase exponentially as the frequency comes down.

      Tesla's motors were by no means restricted to operating at 60Hz.
I don't think baluns have much relevance to this discussion.

Malcolm

 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Sunday, April 04, 2004 12:57 PM
 > Subject: Re: deceptive transformer
 >
 >
 >  > Original poster: "Virtualgod" <mike.marcum-at-zoomtown-dot-com>
 >  >
 >  > Yup, makes them alot lighter with a higher operating freq. I'm
 >  surprised > they don't redesign the whole power grid for khz
 >  operation instead of 60hz > since that sems to be the trend (ferrite
 >  pigs anyone) ;)?. > > ----- Original Message ----- > From: "Tesla
 >  list" <tesla-at-pupman-dot-com> > To: <tesla-at-pupman-dot-com> > Sent: Saturday,
 >  April 03, 2004 8:04 PM > Subject: Re: deceptive transformer > > >  >
 >  Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com> >  > >  >
 >  No, please dont say it's so! They even put switching psu's in MO's
 >  now? > Are >  > the magnetrons designed for the HF also? >  > >  >
 >  ---Eric >  > ----- Original Message ----- >  > From: "Tesla list"
 >  <tesla-at-pupman-dot-com> >  > To: <tesla-at-pupman-dot-com> >  > Sent: Saturday,
 >  April 03, 2004 3:19 PM >  > Subject: Re: deceptive transformer >  > >
 >   > >  >  > Original poster: "Virtualgod" <mike.marcum-at-zoomtown-dot-com> >
 >   >  > >  >  > That's not gonna help the price either with mots going
 >  extinct.
 > Anyone
 >  > try
 >  >  >  > making a dc resonant coil with one of those inverter supplies
 >  yet?
 > Freq
 >  > is
 >  >  >  > probably way too high to make the usual ac coil practical (no
 >  50,000 > bps >  >  > caps to be found). >  >  > ----- Original
 >  Message ----- >  >  > From: "Tesla list" <tesla-at-pupman-dot-com> >  >  >
 >  To: <tesla-at-pupman-dot-com> >  >  > Sent: Saturday, April 03, 2004 12:11
 >  PM >  >  > Subject: Re: deceptive transformer >  >  > >  >  > >  >  >
 >   > Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> >  >  >  > >  >
 >  >  > Also, trash picking or consumer electronics dismantling  as well
 > as
 >  >  >  > storing,
 >  >  >  >  > packing, and shipping, takes time.  One does pay for
 >  convenience > and/or >  >  >  > time. >  >  >  > >  >  >  > Actually,
 >  though, the intriguing thing about the newer microwaves
 > is
 >  >  > the
 >  >  >  >  > inverter power supply!
 >  >  >  >  >
 >  >  >  >  > ----- Original Message -----
 >  >  >  >  > From: "Tesla list" <tesla-at-pupman-dot-com>
 >  >  >  >  > To: <tesla-at-pupman-dot-com>
 >  >  >  >  > Sent: Wednesday, March 31, 2004 4:40 PM
 >  >  >  >  > Subject: RE: deceptive transformer
 >  >  >  >  >
 >  >  >  >  >
 >  >  >  >  >  > Original poster: "Steve Conner"
 >  <steve.conner-at-optosci-dot-com> >  >  >  >  > >  >  >  >  >  >66$ for a
 >  mot is cheap.  New MOTs are 80-100$ AFAIK >  >  >  >  > >  >  >  >  >
 >  Last time I looked, it was possible to buy a brand new
 > microwave
 >  >  > oven
 >  >  >  > for
 >  >  >  >  > 35
 >  >  >  >  >  > UK Pounds. That's about $52. In fact it's probably
 >  less, since >  > consumer >  >  >  >  > electronics are often "dollar
 >  for pound." >  >  >  >  > >  >  >  >  > Still, I don't blame (much)
 >  the seller for trying to make a
 > buck,
 >  > I
 >  >  >  > blame
 >  >  >  >  >  > the poor gimp who paid $66 for a transformer he could
 >  have
 > bought
 >  >  > brand
 >  >  >  >  > new
 >  >  >  >  >  > for $52, or trash-picked for free. Caveat emptor etc.
 >  It's not >  > really >  >  > any >  >  >  >  > worse than paying $100
 >  for a pair of sneakers that cost $5 to >  >  > manufacture >  >  >  >
 >  in >  >  >  >  > Thailand... >  >  >  >  > >  >  >  >  > Steve C. >
 >  >  >  >  > >  >
 >
 >
 >