Re: Bombarder XFMR

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Neonglo-at-aol-dot-com>

In a message dated 11/6/01 3:36:08 PM Central Standard Time, Matt writes:

<< maybe one could make such a choke? if we get the dimentions right.. wind
 some thick gauge wire on some pvc and then use a metal bar as the slider.
 would that produce the same results? one question i have is, do chokes
 have to be wound say like a secondary, or can you put several layers on
 cable on it?
 
 -matt >>

Hi Matt, all,

Three months ago I posted the dimentions for a 5 kVA and a 12.5 kVA sliding 
core choke for neon bombarders or pole pigs. I'll repost it again here:

In a message dated 8/12/01 4:03:24 PM Central Daylight Time, Steve White 
writes:

<< I would like to know the dimensions of your 5 KVA unit. I have been
 wrestling with how to build a reliable ballast at this power level. I would
 like to know the following. >>

Hi Steve, All,

I got the measurements on the 5kVA bombarder choke today as follows:

1. Dimensions of core = 1 5/16" square by 18" long. 3.8 lbs.

2. Bobbin dimensions = 15" by 1 3/8" square ID. Constructed of tempered 
hardboard (Masonite) 

3. Number of turns = Three layers of #10 solid copper, wound 9 TPI, 15" long.

I have put some pix on PhotoPoint of the choke at;

http://albums.photopoint-dot-com/j/PopUpIndex?u=1424805&a=11222029&pw=&size=small

Pictures 5 through 8 are of the choke. A 12.5kVA choke core is shown in pic 
#8 along side the 5 kVA core, along with it's dimensions. 

<< What sort of duty cycle do you get with your ballast? >>

Bombarding usually calls for about 2 to 3 minutes on, and 10 to 15 minutes 
off. This equates to about a 20% duty cycle, but this can be increased 
greatly with the use of forced air across the coil. Add another layer of 
windings to decrease the low end current even more. 

I'd be glad to try and answer any more questions about these chokes. They 
should be simple enough to build, and should work very well with any 
non-shunted tranny, like a pole pig. I have used it before on my TC with good 
results. 

Regards,

Tony
----------------
Tony Greer
Special Effects Neon
Lubbock, Texas
"Flowing Glass and Glowing Gas"
       ~~~SINCE 1980~~~

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