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Re: Found it ! :o(( (was:What is going on?? )
Reinhard, All
< big snip>
> Now, while I know what I did wrong, I find Jon Rosenstielīs
> problem (30mA vs 48mA NSTs, yet exact same resocap) a
> bit hard to understand, because I could actually adjust the
> NST (via itīs movable shunt) to give me the best resonant
> charging condition (i.e: I could match the NST TO THE CAP).
> I tried various cap sizes and could always adjust the NST for
> highest voltage rise (being ~650V in all cases, with 2Vac on
> the primary side. I find that you will have to actually MEASURE
> the output current (to find the proper resocap), rather than
> trust the faceplate ratings. Strangely enough Jonīs NST(s) didnīt
> seem to care what the real output current is. Any ideas ?
> BTW Jon: Did you measure the 48 vs. 30mA?
>
Jon Rosenstiel here....
Tonight I measured a stock Jefferson 15/30 and compared it to my modified
Jefferson 15/48. To measure the current I put a 120 ohm resistor across the
secondary, measured the voltage across it and did the math. Results are 30mA
and 48mA. I also reran the tests with various values of capacitors across
the secondary, 2V input. Everything came out the same as before.
My gut instinct tells me that at 2V input and open circuit, (except for the
meter), output the shunts wouldn't make any difference, but you found that
they do? It would seem that in order to properly run this test the
transformer would have to be putting out it's maximum power. The output load
in my test must be only a few microamps, (the meter draw). The resonant cap
value is derived using the transformer impedance, and the trans impedance is
E/I...
Any thoughts?
Jon