Re: Micro Tesla Coil design

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

Might still be a bit big to be considered a "microcoil".  I'm looking for a
transformer thats no bigger than a C-battery maybe.
Something like 2kV, 1mA max output or similar.
Secondary coil might only be 3/8"-1/2" in diameter.
Be very high frequency - that could pose problems in itself.

Dan


 > 4kv x 9ma that is only 36 Watts! I am using a Bosch ignition coil off a
13.8
 > Volt 3 Amp supply which can't be much different in power. Would this be OK
 > for a micro-coil?
 >
 > Jolyon.
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Thursday, December 19, 2002 3:18 AM
 > Subject: RE: Micro Tesla Coil design
 >
 >
 >  > Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>"
 > <Gary.Lau-at-hp-dot-com>
 >  >
 >  > Rolling your own HV transformer is certainly not my idea of fun.
Larger
 >  > bug zappers typically contain a 4kV/9mA or thereabouts current limited
 >  > transformer somewhat larger than your fist.  I should think that would
be
 > a
 >  > good fit for a palm-top coil.  They're pretty common at flea markets
 >  > (more-so in the summer), and ebay generally has many.
 >  >
 >  > One thing to watch though is some bug zapper transformers (BZT's??)
have a
 >  > potted secondary winding (a good thing), but within the potting is a
 >  > ceramic cap, in parallel with the secondary (bad), to zap the bugs that
 >  > much harder.  You may need to do some precision drilling to remove
that. I
 >  > haven't yet looked at how easy it is to remove the current limiting
 > shunts.
 >  >
 >  > Gary Lau
 >  > MA, USA
 >  >
 >  >   > Original poster: "Mccauley, Daniel H by way of Terry Fritz
 >  > <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>
 >  >   >
 >  >   >
 >  >   >
 >  >   > I'm soon to start designing a microcoil.  The goal of this project
is
 >  > build
 >  >   > a conventional tesla
 >  >   > coil as small as possible and still work.
 >  >   >
 >  >   > Has anyone had experience building one of these things? I know I
saw
 >  > someone
 >  >   > building a palm sized version
 >  >   > on the internet before, but have long ago lost that link.
 >  >   >
 >  >   > Some questions:
 >  >   >
 >  >   > 1.  I'm going to have to build a mini 60Hz step-up transformer from
 >  > scratch.
 >  >   > What should the minimum voltage
 >  >   > output on this be?  I was thinking of having at least a 1kV to 2kV
 > output
 >  > at
 >  >   > 60Hz.
 >  >   >
 >  >   > 2.  Ballasting:  Since this transformer will not have current
 > limiting,
 >  > what
 >  >   > type of ballasting could I get away
 >  >   > with.  I guess at this size (and at the sacrifice of a few volts) I
 > could
 >  >   > use a resistor or even wind a small
 >  >   > inductor on the primary side of the transformer.
 >  >   >
 >  >   > Dan
 >  >   >
 >  >   >
 >  >   >
 >  >
 >  >
 >  >
 >
 >
 >
 >
 >