[Prev][Next][Index][Thread]

micro twin TC 8-)



Hi,

over the weekend I got a portable 3kV -at- 80 watt micro twin (2 times
1.4"x6") TC assembled (pictures will follow soon :o). Gonna switch to DC
later... 

current specs, for those curious:

- 220V 190VA NST, with 10uF PFC
- outputs 3kVAC at 50mA
- 8.5nF flat transparency sheet cap, 20 A5 sized sheets between plexi
  glass
- copper tube spark gap
- 2 old secondaries 1.4" x 6" from earlier. >#37 on each, cardboard form
  coated with urethane, and wire wound on wax paper.
- 2 flat primaries 2" inner diameter, 10 turns of maybe #25 on each
- 2 toploads from metal coffee boxes
- all wiring with thick but cheap microphone audio cable (0.1" dia)

performance notes:

Performance was amazingly good, with just one secondary in operation
there were 2.5" streamers all around the topload, and occasional 4"
streamers trying to reach the coil bottom. That's >1/2 of coil height!
Wow... ;) And this is the first time my secondaries actually keep high
static charge for quite a time - so it's less losses I guess...

What struck me as interesting is that the hits between the two coils are
single about 5"-7" long, slightly curved and fuzzy, jacobs ladder like
arcs. They even rise slowly in proper jacobs ladder manner before they
break down. They aren't white or anything, but soft purple. And no dents
or branches anywhere along.
Sounds a bit like those reports from you larger coil owners about straight
upright rising arcs/streamers.

It looks pretty much like an (enlarged) ground arc from a TV flyback.
It's strange that at such low power levels the "streamers" straighten
out. Well maybe the coil is nothing more than a large scale flyback
transformer at these levels... ?

Well, I hope you found this interesting...
some pictures will follow maybe this week or weekend

greetz,
Jan

--
*************************************************
 Jan Florian Wagner
 http://www.hut.fi/~jwagner