[Amps] Measuring RF Power

[Dennis12Amplify@aol.com]

In a message dated 3/22/05 2:00:14 PM Central Standard Time,  TexasRF at aol.com 
writes:

I lost  track of who said what/when;
In a sine wave the average voltage is zero  therefore average power is  
zero.In an ac circuit with sine wave  voltage, average current is also zero. 
One  
could be led to think  that average power is also zero?



All power formulas square the voltage or current to get rid of those  
negative terms.
 
 The square of a positive number is a positive number.
 
 The square of a negative number is a positive number.
 
 The RMS value is the squareroot of the mean value all of those  
instantaneous power measurements over some finite period of time. 
 
 The period of time over which the RMS value is measured can make a  huge 
difference in the answer.
 
 The commonly known conversion factors only apply to pure sinewaves  and 
averaging over multiples of full cycles of the waveform.
 
 As far as I am concerned, Peak measurements are the only way to  go.
 
 Regards,
 
Dennis O.