Re: variac, dimmer switch?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: DRIEBEN@xxxxxxxxxxxxxxx 

Devon,

>From what I'm told, the problem with trying to use a
light dimmer in the place of a variac is that the light
dimmer electronically "chops" the 60 hz wave form instead
of decreasing/increasing the amplitude of the sine wave.
The iron cored NST does not "like" a diet of "chopped"
wave input and is designed strickly for smooth ~ 60 hz
sine wave inputs. A light dimmer in conjunction with a
a motor run capacitor does make a good control for an
ignition coil since the chopped sine wave starts to re-
semble a pulsed wave, which just so happens to be what
ignition or induction type coils do like :^)

David Rieben

----- Original Message -----
From: Tesla list <tesla@xxxxxxxxxx>
Date: Friday, March 25, 2005 6:43 pm
Subject: variac, dimmer switch?

> Original poster: Devon Ferns <dferns@xxxxxxxxxxxx>
>
> Can you use a dimmer switch to control the input voltage to a NST
> or is
> that just asking for trouble?
> NST is probably going to be 30mA and 12kV that I can use for
> larger coils
> in the future, but the coil I'm building is probably considered
> really
> small. Based off of Derek Woodroffe's coil
> http://www.roffesoft.co.uk/tesla/it/ikletess.htm
>
> I'm asking if it's ok to use for this coil only.  If so is it just
> in
> series with the input of the transformer or are there other things
> that are
> needed to be done?
>
> I know if I was to run a large coil and try and use one it'd not
> be a good
> idea but for such a small one will it work?
>
> Devon.
>
>
>