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[AMPS] RMS POWER

To: <amps@contesting.com>
Subject: [AMPS] RMS POWER
From: billydeanward@hotmail.com (Billy Ward)
Date: Fri, 29 Jun 2001 18:12:03 -0000
I do want to add one little thing.  If you are doing a COMPLETE computation 
of the RMS, you do use the 360 degrees.  The formula starts with E sub 1 not 
E sub Zero, That is the Square Root of the sum of the Squares of each 
indivicual degree 1 through 360.  Or of course you could use Zero through 
379 and cover them all--HI.

Thanks for your help, Bill.

Billy


>From: William Fuqua <Wlfuqu00@pop.uky.edu>
>To: "Billy Ward" <billydeanward@hotmail.com>
>Subject: Re: [AMPS] RMS POWER
To: <amps@contesting.com>
>Date: Fri, 29 Jun 2001 10:11:29 -0400
>
>You know, I was looking at the message I sent. All column date is
>scrambled. I guess I can't use TAB in emails .
>Must use spaces from now on..  My neat table is all jumbled and I am a bit
>surprised that people could make it out.
>
>73
>Bill wa4lav
>
>
>At 04:30 AM 6/29/01 +0000, you wrote:
>>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.
>>
>>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
>>>
>>>
>>
>>_________________________________________________________________
>>Get your FREE download of MSN Explorer at http://explorer.msn.com
>

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