Re: Parallel and Series LCR Circuit Qs

["Ed Phillips" <evp-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:
> 
> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
> 
> Hi Bill,
> 
> At 09:24 PM 8/10/00 -0600, you wrote:
> >On that fateful day 8/10/00 6:34 PM, thus spake Tesla list:
> >
> >> It really is three ohms which is pretty close.  If the primary current is
> >> 12 amps RMS ( a typical primary RMS current), that resistor will burn
off a
> >> whooping 432 watts.
> >
> >Ah, but it's that first bang we're interested in, isn't it?  And doncha
> >think the peak current in that first pulse is a wee bit higher than 12 amps?
> >
> snip...
> 
> The peak current is about 600 amps!!  However, that is only a brief 1% duty
> cycle pulse.  If you look at the continuous equivalent current (the RMS
> value) it is far lower, about 12 amps on my coil.  The RMS value of primary
> current is extremely useful for determining capacitor ratings and such.
> One has to be a little carful about using the AC resistances with skin
> effects in the calculations, but the RMS primary current value really can
> tell you many things.  In this case, it tells the power lost to the gap and
> that I need about four 3amp RMS cap strings for the primary cap...
> 
> RMS primary current equations are giving in the notes at:
> 
> http://users.better-dot-org/tfritz/site/MMCinfo/MMCPower4.html
> 
> Cheers,
> 
>         Terry

	If I haven't slipped a decimal point. the actual RMS current in this
example is 60 amps!  RMS is root mean square.  The square of 600 amps is
360,000 amps^2.  Multiply this by 0.01 (the duty factor) and you get
3600.  Take the (square) root of this and you get 60.

Ed