Re: help- how do i hook up an o-scope?

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

Original poster: "Jeremy Scott by way of Terry Fritz <teslalist-at-qwest-dot-net>" <supertux1-at-yahoo-dot-com>


I wouldn't hook a tesla coil up directly to a
scope. Most scopes can't take more than 400V
or so. That being said, measuring the sparks
off the top of a toriod by directly connecting
it to anything is suicide.

You can only realisticly measure the voltage in
the primary, and use a little math to figure out
what it might be off the toroid. (See the various
Tesla sites for the formulas.)

I've made a probe using a string of high value
resistors. A 100M - 1M - 100M series will divide
the voltage to a reasonable level.
It'll take 10KV and reduce it to 100V.
If you've got a 15kV NST, then you'll see
voltages as high as 212V. If you just want to
see various waveforms, use a 100K resistor
instead of the 1M just to be safe.

Hook the ends of the 100M strings to the high
voltage lines. You measure across the 1M or
100K resistor.

(Still a very high voltage and lethal, but
measurable.)

Don't hold the leads or touch the scope either.
If you have to adjust it, put your other hand
in your pocket. Remember that even at 100-200V
there is enough amperage in the tank circuit
to kill you several times over.


--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: "davep by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <davep-at-quik-dot-com>
 >
 >
 > >I need some help in using an o-scope.
 >
 >          To do what?
 >          It is a powerful tool, with multiple uses.
 >          The usual course is a one semester class
 > and that
 >          DOES NOT get into HV specific stuff.
 >
 > >Can someone point me in the right direction?
 >
 >          Depends on what direction is desired.
 >
 > >One of the big questions that I have is: how do I
 > know where to hook it up?
 >
 >          May not need, or wish, to 'hook it up'.  I
 > see
 >          a post explaining using an 'antenna' to
 > pick
 >          up via noncontact means.
 >
 > >I know that you can't just randomly connect the
 > leads to different places.
 >          Right.
 >
 >          Depends on what the objective is...
 >
 >          (If this seems vague:
 >          There are hundreds of lines that could be
 > written
 >          on this subject.  cf also the list
 > archives...
 >          8)>>)
 >
 >          best
 >          dwp
 >
 > ...the net of a million lies...
 >          Vernor Vinge
 > There are Many Web Sites which Say Many Things.
 >          -me
 >
 >
 >
 >