[Prev][Next][Index][Thread]
Re: 2 questions on resonance
In a message dated 99-04-09 05:00:58 EDT, you write:
<< > With the larger capacitor mentioned by Gary and Terry, one must
>also get some partial cap charging after dwell as the transformer
>comes down off its peak but this time the larger capacitance taken
>with a limited energy delivery capability (which I think always
>exists) cannot cause Vcap to exceed the peak transformer voltage.
>With the gap set wide enough in the first case, I think you will get
>just as much energy in the cap as in the second, the disadvantage
>being the much higher voltage the smaller cap has to reach to reach
>the same energy storage. I still don't see any evidence that the
>transformer can do better than its faceplate VA rating.
> The big cap idea sounds like it should be a firm recommendation
>for capacitor sizing rather than the now (apparently) dated notion of
>going for an Xl=Xc match. There is some inherent protection for the
>transformer built in by way of secondary voltage limiting per half
>cycle as a bonus.
>
>?
>Malcolm
> >>
Malcolm, all,
My latest tests, which I posted separately, support most of what
you say above. But I was only able to achieve it using a sync gap,
not with static gaps. Maybe static gaps are too chaotic to permit
meaningful downside charging?
Regarding current draw, I had to turn up the voltage to 140 volts
input for the larger-than-resonant cap situation to obtain 620 watts
of current draw. But the resonant charging situation drew this same
current input using only 120 volts input. I'm using a 12kV, 30ma
NST (360 watt nameplate).
John Freau