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Old 13th March 2010, 09:20 AM   #191
EUVL is offline EUVL  Europe
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You divide peak VOLTAGE by root 2 to get Vrms. But it is also the same for current in resistive load. So power is divided by 2.

Or am I still wrong ?

Patrick
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Old 13th March 2010, 11:21 AM   #192
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Audio power - Wikipedia, the free encyclopedia
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Old 13th March 2010, 02:47 PM   #193
juma is offline juma  Germany
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Quote:
Originally Posted by EUVL View Post
You divide peak VOLTAGE by root 2 to get Vrms. But it is also the same for current in resistive load. So power is divided by 2.

Or am I still wrong ?

Patrick
Sorry Patrick, I don't know why I asked at all - absolutely unimportant because this calculation assumes pure resistive load and sinusoidal signal - pretty much useless in real life.
Peak voltage/current value might be informative - it determines the clipping limit, the rest is of no use, unless we want to go into really complex modeling...
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Old 13th March 2010, 03:02 PM   #194
EUVL is offline EUVL  Europe
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> Peak voltage/current value might be informative ....

That we agree.

And in post #189 I was working back from what Nelson quoted in post #186 back into, exactly as you said, voltage, current, and thermal dissipation.


Patrick

Last edited by EUVL; 13th March 2010 at 03:05 PM.
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Old 13th March 2010, 04:35 PM   #195
Blues is offline Blues  United States
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Quote:
Originally Posted by EUVL View Post
You divide peak VOLTAGE by root 2 to get Vrms. But it is also the same for current in resistive load. So power is divided by 2.

Or am I still wrong ?

Patrick
This is correct. The square of the square root of 2 is equal to 2...

Prms=(Vrms)^2/R

since Vrms=Vpk/sqrt 2 then:

Prms=(Vpk/sqrt 2)^2/R; this then equates to:

Prms=(Vpk^2/2)/R)=Vpk^2/(2*R) or the customary =(Vpk^2/R)/2

As an example with the known values Vpk=20V and R=8

Prms=(20^2/8)/2=25 watts
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Old 13th March 2010, 05:08 PM   #196
EUVL is offline EUVL  Europe
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> Or am I still wrong ?

It was not supposed to be a question.


Patrick
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Old 7th October 2010, 05:29 PM   #197
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Hi Nelson,

I was wondering how this project was coming along. Have you had a chance to do any preliminary or even serious listening and if so can you share your thoughts on the sound?

Thank you.

Graeme
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Old 8th October 2010, 12:47 AM   #198
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At this time I have 5 pc boards completely stuffed, ready
for action. Four of them perform as previously described,
and one of them has a little extra distortion.

I began searching for the bad device by measuring the THD
at the Source pin of each of the 588 devices on the board,
and I got half way through before I had to go work on other
things for a while.

In actual testing the best performance looks to be with
supplies in the +/-15V area - battery operation is very
feasible. To get the power up I can run two pc boards
in balanced mode, and this looks like what I may do,
creating one stereo pair at about 40 watts and a single
board suitable for two channels at 10 watts or less.

I may have it a BAF, then again I might have something
else.

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Old 8th October 2010, 05:49 PM   #199
nar is online now nar
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Quote:
In actual testing the best performance looks to be with
supplies in the +/-15V area - battery operation is very
feasible. To get the power up I can run two pc boards
in balanced mode, and this looks like what I may do,
creating one stereo pair at about 40 watts and a single
board suitable for two channels at 10 watts or less.
I think this project is awesomely insane
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Old 8th October 2010, 07:29 PM   #200
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It's become the Beast With 2,352 Jfets.

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