On Wed, 31 Aug 2011 12:33:06 -0700 (PDT), NT
wrote:

On Aug 31, 7:11*pm, John S wrote:
On 8/31/2011 1:06 PM, The Ghost In The Machine wrote:



YES A-NT-MAN BUT THE RMS REFERS TO THE AC WAVEFORM NOT THE DC OUTPUT.
HENCE THERE IS NO SUCH THING AS RMS DC VOLTAGE.
PATECUM
TGITM

Root Mean Square does not imply an ac waveform, its jsut most commonly
used for ac waveforms. Every stable waveform has an rms value, even
perfect dc.


Actually, RMS DC voltage is a redundant expression since DC is RMS.

I realised it was perhaps not the best phrasing. But... would the dc
component be the average V or the rms?


NT

Generally, in electronics, "DC component" is defined as the average
value (say, over a period of a periodic waveform). So a 1V peak sine
wave sitting on top of 1VDC would have DC component of 1.0V.
A 1V peak sine wave has a DC component of 0.

The RMS value is the heating value- a 1 ohm resistor with 1VDC across
it will dissipate 1W. A 1 ohm resistor with 1.414V peak sine wave
across it (1 V RMS) will dissipate 1W.

A 1 ohm resistor powered with a 1V peak sine wave sitting on top of
1VDC will dissipate a bit more than 1 watt (RMS value is sqrt(3/2) if
you want to get analytical about it, so about 1.22W).