Re: EMI Filters

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Paul B. Brodie" <pbbrodie@xxxxxxxxxxxxx>

Karl,
I'm, sorry, my hands were typing before my mind was functioning! The EMI 
filter is wired between the variac output and the coil driver. The volt 
meter is "behind" the EMI filter along with my house wiring. Now I'm 
concerned about running my Tesla Coil from my house supply as I have a ton 
of sensitive computer equipment in the house. I do have a separate RF 
ground outside. It is an 8 ft. ground rod in the ground just outside of the 
garage. I have another 20A EMI filter and I think I will wire it in between 
the wall outlet and the variac so that I have 2 EMI filters with the variac 
in between them.
Paul
Think Positive

----- Original Message -----
From: "Tesla list" <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
To: <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
Sent: Friday, May 06, 2005 2:18 PM
Subject: Re: EMI Filters

> Original poster: Karl Lindheimer 
<<mailto:karl@xxxxxxxxxxxxxxx>karl@xxxxxxxxxxxxxxx>
>
> Hi Paul,
>
> If I understand correctly, you state that the EMI filter is between the
> wall outlet and the variac?  If that is the case, the filter will only
> reduce any back EMI from reaching the wall outlet and the rest of the
> connected house wiring on the same circuit.  The variac and meter are still
> exposed to the EMI from the coil.  My flyback transformer experiments also
> created huge RF/EMI necessitating that I disconnect any valuable/sensitive
> equipment from the AC line.  I ended up building a robust simple power
> supply to spare my lab grade bench supply.
>
> Karl
>
> On May 5, 2005, at 1:20 PM, Tesla list wrote:
>
>>I have a 20A EMI filter wired in reverse between the wall outlet and my
>>variac. I have a volt meter attached to the variac outlet.
>>
>>I was driving one of my ignition coils with a 600 watt dimmer in series
>>with a 2mF cap. As I powered up the variac, I could read the voltage
>>increasing on the volt meter all the way up to 120V. When I turned up the
>>dimmer, the voltage indication on the volt meter went haywire when the
>>coil began sparking. If I drew the ground away from the HV output, the
>>volt meter would stabilize as soon as the sparks stopped.
>>
>>What have I missed here? This isn't normal, is it??!! Could the EMI filter
>>be bad?
>>Paul
>>Think Positive
>
>
>