[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: Some newbie questions



Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com> 




 >Original poster: "Aaron Aab" <striker754-at-earthlink-dot-net>
 >
 >Hey guys!
 >
 >Building a coil in my garage, and have a couple questions.
 >
 >Can I drill a hole in the pvc pipe and run the 2 ends of the secondary coil
 >inside the pipe to a lug in the caps and then use a bolt to exit the pipe?

That's generally a bad idea, as it invites arcing along the interior 
surface.  But the mechanical benefits of what you propose are 
tempting.  I'd recommend placing a pair of plastic disks or baffles inside 
the pipe just inside the ends of the coil.  Cement them in place using a 
liberal dose of PCV cement.  Then make the holes so that the two disks are 
between them, blocking and arcing.

 >Does everything needing to be grounded go to the same ground rod? Strike
 >rod, secondary coil, etc?

Yes.

 >Are there any cheap protection I can use to protect the NST? I don't want
 >to spend 50 bucks worth of stuff for that one protection circuit. Will a
 >safety gap, and 2 chokes work well? Chokes are just magnet wire wrapped
 >about 100 times around a pvc pipe correct?

The use of chokes was advocated before folks began simulating and scoping 
what actually happens.  Don't use them, they cause more problems than they 
solve.  Instead use R-C filters.  Two 1000 pf 10kV ceramic disk caps in 
series ($1 each) between each NST HV bushing to the case, and a 1K 50W wire 
wound resistor from each bushing to the main spark gap.  And a safety gap 
from each HV bushing to case.

 >
 >Thanks a bunch!
 >
 >Aaron

Regards, Gary Lau
MA, USA