Quote:
you mutlipy the wattage (VxA) by 0.707
to get the true watt.
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Oh well, dunno who this might interest, but anyway...
IIRC, 0.707 is the ratio between peak and RMS voltage.
The ratio between VA and W is the Cos(Phi) or Power factor. This varies between 0 and 1 depending on how inductive or resistive the load is.
purely resistive load (eg heater?), Cos(Phi)=1 so W=VA.
purely inductive load (ideal coil), Cos(Phi)=0, so W=0 (!)
Ok,
here's another nice little link, with colourful sine curves etc.