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Re: Baby Tesla
>Thanks you for the relpy of my letter. If you could, would you be able to
>send me a text drawn circuit diagram, with the components and values.
Martin my circuit is fairly experimental - lots of inefficencies, and bugs!
And its expensive.
A bit complicated for a text diagram - (SAE?)
Essentially it is a CA1524 PWM controller chip. driving some logic
that switches off if the current is too high driving a MAX4427CPA
dedicated mosfet driver, driving 2 irf740's. After blowing a lot of
fets in lash ups I am now building very carefully towards 150v
and 500w.
This drives an 18 turn primary with pulsed DC, 220khz, 75v 1A
at the moment. The primary is wound on a 15" high, 12" diameter
plastic bucket. spaced over the whole hieght of the bucket.
In the bucket sits a 4" diameter 30" high pvc pipe, wound with
1600 turns of 24swg enamelled wire, bottom end of the wire to
electrical earth, top end is wired to a foil covered donut, the
end is open to air.
You could go as I suggested with a Line output transformer, or go for the
neon transformer - home made capacitor, sparkgap kind of beast.
Or get hold of the CA1524 data sheet build the pulse generator
described there but with rt=2k2 + 4k7pot, ct=1200pf - then start on
the rest.
Or get Daune Bylunds book - modern tesla coil theory. Good material
poorly presented (looks like was done on a roneo).
Or get a switching psu out of an old computer and do some serious
rewiring to the transformer and timing.
>P.S. I first heard about the tesla coil, when a friend and I managed to get
>hold of a borrowed diagram and some documentation. Is it true that the tesla
>coil is more than a hundred % efficient?
There is a lot of new age nonsense written about this, zero point energy etc
and Tesla himself may have sparked it of with his writing.
I suspect that a lot of it is due to the dificulties of measuring very high
voltages and currents, plus a failure to allow for power factor correction
P=IV only if voltage and current are in phase.
A tesla coil is an air core transformer working at its resonant
frequency. The secondary coil, together with its self
capacitance to earth forms a tuned circuit, hit the resonance
frequency and ocillation gets bigger and bigger till it breaks
out and sparks. The efficency is limited by the Q of the system - you never
get 100%. More than 100% is impossible. I suppose that there may be
a chance that there is a free energy source out there waiting to be
tapped - but if anyone could do it, they would build one and make millions.
>P.P.S We also saw that it was possible to use the high voltage end like a
>transmitter, and using specially designed receiving ariels to pick up this
>power and light bulbs, etc. Is this true?
Yes, Tesla pioneered our modern system of AC power distribution, but he
planned the wireless production of electricity. He built a huge coil and
radiated power for miles - it would actually work - but its very hard to
charge people for what they use. My coil running at 75w will light an
ordinary neon tube 3 feet away - without any wires - you can imagine
what the big ones will do.
Come back at me if you want more details, let me know where
to pitch the tech stuff.
Have fun
Alan Sharp (UK)