[Boatanchors] Speech Amp CORRECTION

[rbethman]

AFAIK,

correction in three phase "notation."

This formula won't hunt!  Please provide reference for P = V*V/R.

P = E*I,   E=I*R and etc

Three phase power - P =   3^(1/2)  E line * I Line * cos Theta.  [That's
the square root of three BTW.]
>
> Since Power = V * V /R, if R=600 ohms and V=70 volts, there is only 
> one possible power output from the amp. (4900/600 = 8.1 W)
>
Bob - N0DGN


J Forster wrote:
> Take a look here:
>
> http://www.dvq.com/hifi/images/260a.pdf
>
> AFAIK, 600 ohms is used for inputs, not outputs, and is typically 
> balanced.
>
> A 70 V line means that the amp output is 70 V RMS at the amp's rated 
> output. The 70 V is usually stepped down at each speaker to voice coil 
> impedance. Typical transformers have taps for the desired wattage to 
> the speaker, so you can hook up a number of transformer/speaker 
> combos. So on a 10 W amp, you can hook up four 1 W and three 2 W 
> speakers. The amp looks a lot like a voltage source.
>
> Since Power = V * V /R, if R=600 ohms and V=70 volts, there is only 
> one possible power output from the amp. (4900/600 = 8.1 W)
>
> Nope, 600 ohm and 70 V are NOT the same.
>
> -John
>
> ==============
>
> Barrie Smith wrote:
>
>>   It's my impression that the 70 volt output on a PA amp is 600 ohms. 
> ------------------------------------------------------------------------
>
> _______________________________________________
>   

-- 
Bob - NØDGN

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