Re: DRSSTC - I think I heard Cross Conduction...

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Sue Gaeta <sgsparky@xxxxxxxxxxx>

Hi Colin,
Your comment about noise reminded me of something else that was happening 
while I was using the larger topload.

I always hold a piece of metal in my hand when I do these tests so that I 
can touch various equipment with it instead of my bare unprotected skin. 
This prevents me from getting those little "RF bites" everytime I touch the 
power switch, or whatever. It is my own little "bonding on" approach. I 
also try to draw little arcs off the ground braid to see how much RF I am 
picking up. I noticed that with the larger topload, I was picking up much 
more RF. Not only that, but everytime I moved, the output would change 
slightly. These effects went away when I switched to the smaller torroid. 
This indicates that the noise in the electronics could very well be caused 
by radiated emissions. It makes sense, more metal on top will act as a 
better radiator than the little torroid.

I do use a line filter on the power cord that supplies the H bridge, but I 
don't have one on the driver supply cord. This could be an "uh oh" if I get 
brave enough to feed this thing more power. I haven't gone above 130 AC 
input yet. These filters work both ways, and would most likely eliminate 
any noise picked up by the line cord. The ones I own have both common mode, 
and differential chokes. I think most of the commercial ones are made that 
way.

A shielded line cord could be another good solution. If I ever got a coil 
working as good as these other guys out there I think I would also need it 
in case a streamer hits the line cord. I don't have to worry about that 
right now though. Not even close!

Tesla list <tesla@xxxxxxxxxx> wrote:
Original poster: "colin heath"

hi sue,
When I build the bigger H bridge, I have to look into why I can't
use as
much top loading as Steve W. uses. I have enough extra turns available to
get it in tune, but I get smaller sparks, and it draws much more current
:-(.
Sue
i to have found this with my coil. as well as drawing more current the
problem with noise on the electronics gets much worse!
cheers
colin