RE: Tap tunable secondary

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

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

Hi Godfrey,

I think they are 18kVA.  Custom made and oil filled.  Sort of light weight
mini pigs.

Cheers,

	Terry

At 10:51 AM 12/30/2001 -0600, you wrote:
>Hi Terry
>
>Can you give an example of what sort of large heavy HV transformers you and
>others moved.
>
>Godfrey Loudner
>
>> -----Original Message-----
>> From:	Tesla list [SMTP:tesla-at-pupman-dot-com]
>> Sent:	Sunday, December 30, 2001 12:39 AM
>> To:	tesla-at-pupman-dot-com
>> Subject:	Tap tunable secondary
>> 
>> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>> 
>> Hi All,
>> 
>> Many thanks for the great ideas.  I never thought of "adding" a small coil
>> wound in the "opposite" direction to reduce inductance.  That will be easy
>> :-)  I could spend a lot of time figuring out the perfect coil to use, but
>> it is faster just trying it to see ;-)
>> 
>> Today, I and all the other "mad scientists" here in Denver, spent all day
>> today moving Bill Lemeiux to his new home (and giant garage :-))).  Bill
>> has literally "many tons" of HV equipment so my muscles may not be working
>> tomorrow :-p But I'll try to wind a coil anyway ;-)
>> 
>> Also met up with Dave McKinnon (D&M's High Voltage) today for a real nice
>> chat between moving large heavy high voltage transformers... ;-)))  Must
>> rest now...
>> 
>> Cheers,
>> 
>> 	Terry
>> 
>> 
>> >Hi All,
>> >
>> >I am having problems tuning my CW coil.  It is run off a variable
>> frequency 
>> >900 watt, 325 to 375 kHz, industrial plasma power supply.  I can wind 
>> >matching transformers on big 3C8 cores to fix input impedances, but the 
>> >frequency is a problem.  It has a master oscillator frequency control so
>> it 
>> >does not track with fancy feedback, PLLs or anything like that.  But I
>> can 
>> >adjust the frequency by hand.
>> >
>> >The problem is the secondary frequency.  If I place different top loads
>> on 
>> >it (like the power arc tonight) It tends to drop the optimal resonant 
>> >frequency too low and I can't get to the optimal frequency given the
>> power 
>> >supply's range.
>> >
>> >So I was thinking of making a new secondary with tap points on it so it 
>> >could be taped at different frequencies.  About 5 inches on one end will 
>> >have a bunch of wire loops coming out.  I don't know if it would be best
>> to 
>> >put these taps at the top or bottom of the coil.  I am worried about 
>> >autotransformer action and other problems with the unused windings.  
>> >
>> >Any thoughts on this are welcome.  I don't remember anything like this
>> being 
>> >discussed before but maybe the long time tube coilers have run into this
>> and 
>> >have some ideas.  I want to pump the full 900 watts forward (plus 250 
>> >reflected if needed) into a power arc to see if I can make the sparks
>> Richie 
>> >got.
>> >
>> >Cheers,
>> >
>> >	Terry 
>> 
>