Re: Current Limiting and Impedence

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Paul B. Brodie" <pbbrodie@xxxxxxxxxxxxx>

Mark,
Please excuse the intrusion. I am following this thread with great 
interest. When you say you are measuring the "voltage between the inductor 
and transformer," where are you attaching the voltmeter? I am having 
trouble understanding what you mean by between. Thanks for any clarification.
Paul
Think Positive

----- Original Message -----
From: "Tesla list" <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
To: <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
Sent: Wednesday, April 27, 2005 1:00 PM
Subject: Re: Current Limiting and Impedence

> Original poster: "Mark Dunn" <<mailto:mdunn@xxxxxxxxxxxx>mdunn@xxxxxxxxxxxx>
>
>
> Gerry:
>
> Thanks for all your help.  Now if you can bear with me and help me solve
> the original problem with the math(BTW <> is "not equal to")....
>
> I have (2) inductors in series.  My current limiter and my transformer.
> Mains is 120V/60 Hz/1 ph.
>
> The current limiter is 15 mH, X = 5.65 Ohms, R = 0.3 Ohms.
> The transformer is Z = 1.2 Ohms, R = 0.3 Ohms, so X = 1.16 Ohms
>
> So System Impedence Z = 6.82 Ohms
>
> This gives I = 120/6.82 = 17.6 Amps and is near exactly what I am
> getting.
>
> The measured voltage between the inductor and transformer is about 90 to
> 95 volts.  Have gotten as high a 100 volts.  This is the voltage drop
> across the transformer.  This is inconsistent with the above values and
> in fact seems reversed from what the math suggests.  I have double
> checked it.
>
> For more confusion, lets compute power:
>
> True power = R*I^2 = 0.6*17.6^2 = 186 watts
> Reactive power = X*I^2 = 6.81*17.6^2 = 2109 var
> Apparent power = 2117 VA
> Power Factor: 186/2117 = .08 (makes no sense)
>
> I know I have 120*17.6 = 2112 VA input and approx 7500*.2=1500 watts
> output from the transformer secondary. Thus I have a power factor of
> approximately .71.  I get 48 to 60" sparks from the coil/toroid so I've
> got to have near that kind of power.
>
> I believe that I am improperly accounting for the power that is
> transferred from transformer primary to secondary in the above
> equations.  It's as if some of the reactive power "created" by the X of
> the inductor is actually true power for the transformer.
>
> I tested the current limiter and don't think it is saturating.
> (BTW - I'm a "math guy" so I can handle the vector addition and complex
> variables no problem.  But struggling with setting up equations and how
> to apply them.)
>
> Thanks again for your help.
> Mark
>
>