Re: flyback transformer HV question

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

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Ryan,

At 07:33 PM 8/6/2003 -0600, you wrote:
>Hi all,
>
>    I've been playing with some flyback transformers, and have succeeded in
>producing 1-2cm sparks from the HV output (the wire that had the suction cup
>on it). I can't seem to find the HV return wire on any of my transformers
>(I'll build my own soon enough), but I can generate sparks to a grounded
>wire.

That is pretty good!  The voltage you are getting can be estimated from the 
chart at:

http://hot-streamer-dot-com/TeslaCoils/Misc/SGapVolt.jpg


>I'm using a simple, single transistor driving circuit on the transformer.
>I'm trying to use this as a driver for a plasma globe. This HV lead does not
>seem to turn lightbulbs into plasma globes. I'm just putting the HV lead
>onto the baseplate of the bulb (I've also tried tying the bulb "return" to
>ground). I've tried various type of bulbs. A 40W clear bulb was allowing
>arcs through the glass to a grounded wire, but no streamers inside.

There are many types of bulbs.  Many are filled with normal air pressures 
but an inert gas that will not light.  I might suggest a type H39 Mercury 
vapor bulb.  These are common at the hardware store and are used by 
homeowners that have those bright outdoor lights.  the usually cost about 
$8.00 but they do have some glow to them.

http://hot-streamer-dot-com/temp/P9290027.jpg


>Does this indicate that my transformer has internal diode(s)? Am I hooking
>up the bulb right? Anyone know?

A 30kV diode I have here is 3.25 inches long and not cheap.  I doubt you 
have any diodes to worry about there.  If you can draw a big arc, you've 
got voltage!!!

Cheers,

         Terry



>Thanks!
>Ryan Molecke