Yeah, I guess your right Bill. ENOUGH! I have not made myself clear and it
is probably my fault. The below is standard stuff that I knew and have been
teaching for 30 years. It still does not answer my question. I will
re-group and later on, if I have not figured out what I am trying to figure
out, I will find a better way to ask the question.
Thanks Guys,
Billy
>From: William Fuqua <Wlfuqu00@pop.uky.edu>
>To: <amps@contesting.com>, <billydeanward@hotmail.com>
>Subject: [AMPS] RMS POWER
To: <amps@contesting.com>
>Date: Thu, 28 Jun 2001 13:21:47 -0400
>
>OK enough...
>
>RMS has one meaning, definition or procedure if you want to call it that.
>
>R take square root
> of
>M the average (mean)
> of
>S the square of a number of data points
>
> It may look complicated as an equation or an integral expression
>(calculus)
>but it is SIMPLE!!!!
>
>For example...
>
>
>Take one cycle of a 1 volt sine wave and divide into at least 8 equally
>spaced points starting at zero degrees.
>Calculate instantaneous voltage, voltage squared and power into 50 ohms
>load at each point.
>Do not use 360 degrees because it is the same point as 0 degrees. You may
>do this for any number
>of full cycles and you may want to do this on a spread sheet for each
>degree (ie 360 points) or what ever.
>
>Phase Voltage Voltage Squared Power into 50 ohms
> Watts
>0 0 0 0
>45 .7071 .5 .01
>90 1 1 .02
>135 .7071 .5 .01
>180 0 0 0
>225 -.7071 .5 .01
>270 -1 1 .02
>335 -.7071 .5 .01
>
>totals 0 4 .08
>average of totals .5 .01
>Square Root of average .7071
>
>
>The RMS value of the signal is .7071 times the peak (1 Volt)= .7071
>volts GEE look at above bold and underlined.
>
>What is the power of this signal into a 50 ohm load?
>.7071 volts squared divided by 50 ohms= .01 watts Look again above at
>the average power bold.
>
>It is all very consistent with calculations using RMS voltage or
>Current and resistance and power.
>
>Now what happens when we take RMS of the Power??
>
>
>Phase Voltage Voltage Squared Power into 50 ohms Power
>Squared
> Watts
>0 0 0 0
> 0
>45 .7071 .5 .01
> .0001
>90 1 1 .02
> .0004
>135 .7071 .5 .01
> .0001
>180 0 0 0
> .0
>225 -.7071 .5 .01
> .0001
>270 -1 1 .02
> .0004
>335 -.7071 .5 .01
> .0001
>totals 0 4 .08
> .0012
>average of
>totals .5 .01 .00015
>Square Root of
>average .7071
>0.01225 RMS power ?????
>
>OK above is your RMS power for what ever good it is....
>And it does not relate to any of the other numbers you may use such as
>voltage, current. resistance or power. But does give you 22.5% bigger
>number in this example.
>73
>Bill wa4lav
>
>
>
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