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RE: Oops ? To A.C Kuntz
I did some major snippage.. I'll take a stab at answering these problems
though I am still just learning this stuff.
First, some persective..
at 50A, yes, he dissapates 1250W in the resistor, of 12KVA(at 240V), or 10%
at 30A, 450W, of 7.2KVA, or about 6%
at 20A, 200W of 4.4KVA, or < 5%
So.. less than 10% overall. While it would be nice to have that extra 10,
there is another aspect:
You mention that a floresent lamp ballast does not have a resistor.
Nor that a neon does. Both quite true. Neither system must deal with
the wildly fluctuating currents we subject our systems to.
Consider: A pig could have current swings of 2-300%, or more, in
accordance with the break-rate. A florescent is static.. constant
current flow. A neon is designed for the same. I speculate that
we don't get the 'THUMP' from a neon for 2 reasons. 1) the magnetic
shunts tame the fluctuation in TC use. and 2) we don't generally at the high
power levels of a pig with a NST.
In further support of 1) above, I run with 3 shorted neons as my ballast
without resistors and I don't get the thumps mentiond by others. I think
the neons moderate the swings in current just by way they operate.
> >SNIP
> >0.5ohm? But I calculate that if you are drawing 50amp to power your=20
> > coil then that resistor will make 1250 watts! This seems like the
> wrong=
> >=20
> > way to do things, why doesn't the inductor just work.
> >=20
> >SNIP
> >
>
> It does not matter what else is inthe circuit, if the 0.5 resistor has
> 50ampRMS flowing through it, it will get 1250watts!! this is a bad
> design. A properly designed inductor should just work, you dont see
> commercial florescent light ballast or NST with resistors in them!!
>
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