RE: Odd Overloaded NST Effect
When using a static gap, the current drawn by an NST is extremely chaotic.
This isn't at all evident unless you have a current meter (obviously,
sorry). With my single 15/60 NST and static gap, my analog current meter
swings wildly from 12 amps to pegging its 20A limit. My NST is a Jefferson
Electric and seems to process more power than most others report, probably
due to the magnetic shunts saturating with my LTR cap. Perhaps Jefferson
NST's, which have a unique (non-removable) shunt construction, saturate
sooner and this is why I can pull so much current from it? But I digress...
Now, if you have three times the NST than I have hooked up, you will draw a
LOT of erratic current. I'll bet that either your variac or 115V AC wiring
is causing a substantial voltage drop at the current peaks. The "no limit"
reply to the how many variacs can be paralleled question was probably mine.
I should amend that to "as many as your variac and wall socket can supply
current to without excessive voltage drop".
Regards, Gary Lau
Waltham, MA USA
Original Poster: "Ryan Ries" <spud-at-wf-dot-net>
I have 6 15Kv-at-30mA transformers connected together
for a monsterous output
of 180mA; at least theoretically. The current from my mains
through my variac first, which has a built-in voltmeter.
When I apply
power to my transformer bank, I notice the voltmeter goes
back and forth between about 90 and 145 volts. I heard
talking about the voltage field collapsing as the current
field goes too
high in an NST, or something wacky like that. The last time
I asked how
many NSTs could be paralleled successfully however, the only
response I got
was "there shouldn't be any limit". So, what do you think
is the deal?
-- Ryan Ries