Re: PFC's gooooood...

[Neonglo-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 10/6/00 5:17:34 PM Central Daylight Time, tesla-at-pupman-dot-com 
writes:

<< John -
 
 Note that 1.7 amps x 120 volts is 204 watts. The 15/30 NST output is 450
 watts. Output greater than input? Something is wrong.
 
 John Couture >>
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John M, John C, and all,

The nameplate rating on neon transformers is at open circuit voltage, and 
short circuit current. So output power is not found by multiplying the 
nameplate voltage times current. A properly loaded neon tranny will typically 
run at 55% of the nameplate voltage WHILE outputting 80% of the nameplate 
current, that is, in regular neon service. So a 15/30 neon tranny will 
actually put out only 8250 volts while supplying 24 ma. of current. This is 
equal to 198 watts of continuos power output. 

Note that a normal power factor tranny will draw 3.75 amps at 120 volts, and 
that is equal to 450 volt-amps, but only 250 REAL watts. Now the same tranny 
with PFC will draw only 2.1 amps at 250 real input watts. After resistive and 
magnetic losses in the tranny, you get about 198 watts of useable output 
power.

I'll bet an accurate check of the line current would yield about a 2.1 amp 
average current for a perfect PFC value, which John M seems to have hit. 

These figures are based on largely resistive loads such as neon tubes, and of 
course will behave differently in Tesla coil circuits. But I hope this gives 
a better idea of how neon transformers are rated. This "55% of the voltage" 
at "80% of the current" rule will hold true on almost any size magnetic neon 
tranny.  

Be Curious!

Tony
      
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Tony Greer
Special Effects Neon
neonglo-at-aol-dot-com
Lubbock, Texas
"Flowing Glass and Glowing Gas"