Re: Current Limiting and Impedence

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>

At 00:09 08/05/05 -0600, you wrote:
> Original poster: "Gerald  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
> I'll reply to my own reply.
>
> Maybe what I'm missing is:   if I increase the area to prevent saturation, 
> the inductance goes back up so maybe this is self defeating.

Yes. That's exactly what the issue is. If you design a gapless ballast so 
it won't saturate, then the inductance will be too high to let any decent 
current flow. If you design it with low enough inductance to pass your 
desired current, it will saturate too early.

If you want a practical demonstration, try ballasting a fluorescent lamp 
with a transformer primary instead of the proper ballast. No matter what 
you do, you can't find a tapping point that makes it work, it goes straight 
from a dim flickering light to saturating and burning the lamp out. Well 
that's what happened when I tried it. YMMV especially with a poor quality 
transformer like a MOT (these have a small air gap due to their welded 
construction)


Steve Conner