Re: o-scope tuning of tesla coil?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Antonio Carlos M. de Queiroz" <acmdq@xxxxxxxxxx>

Tesla list wrote:
>
> Original poster: "Black Moon" <black_moons@xxxxxxxxxxx>
>
> hmm.. im not sure if this is working... even adding a few turns on the
> primary seems to have little or no effect, can't seem to get
> primary/secondary tuned quite right... anyone know how to do it with both
> secondary and primary hooked up? (osilator to primary) and what the o-scope
> pics look at diffrent tuneing levels? seems to be getting about a 10x
> voltage gain and the secondary voltage is peaking in a few cycles (7 or so)
> with high coupleing...

The most effective method, I think, is to connect in series with
the primary circuit (across the spark gap, with the power supply
disconnected) a low-frequency square wave generator, with low output
impedance. Each transition of the square wave will produce a waveform
similar to what will appear in actual operation. Look at the voltage
across the primary inductor, and when the tuning is correct you
will see complete beats:

http://www.coe.ufrj.br/~acmq/tesla/tefpreg1.jpg

This waveform was obtained with this setup:

http://www.coe.ufrj.br/~acmq/tesla/tuner.gif

You can use a signal generator (square wave) too, but you need a very
low
output impedance. A 1 Ohm resistor connected across the output of a 50
Ohms generator is usually enough.

Antonio Carlos M. de Queiroz