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Phil Allison[_3_] Phil Allison[_3_] is offline
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Default voltage of dimmer output not reading same on two different DVM's

Ron D. wrote:
=============
let's say the following:

TRMS meters generally have AC and AC+DC modes, but usually your interested in the AC portion.


** Not true.

The reason for needing a true RMS value is to predict heating in a resistance or maybe a fuse .
So you cannot omit the DC component.


AC meters have a frequency response.


** But DC ones do not and so are all the same.


We talk about average, but the average of a typical sine wave is zero.


** Correct.

Standard AC meters show the "average *rectified* value " scaled up by 11% to the RMS for a sine wave.


...... Phil