Full load efficiency of High-Voltage Input Switching Power Supply using StackFET
Can anyone tell me how efficiency and stand by power is calculated as done here:
http://www.powerint.com/sites/default/files/PDFFiles/der58.pdf
Comments
OK.But my actual question is how the effeciency is calculated?? What if i measure the current (in rms) supplied to any one of the three phases,then measure voltage (in rms) at that phase and then multiply the measured voltage and current to find the AC power. Then divide the output DC power by the AC power to calculate efficiency. Am i right??
Can anybody answer my question??
No that would be incorrect. Real power is the product of instantaneous current and voltage which needs to take into account phase information. Since RMS does not have this information it would yield incorrect information.
If you can find out what the power factor of the circuit is then the real power can be computed by Vrms * Irms *cos(phi) where cos(phi) is the pf.
Efficiency and standby measurements are only shown upto 265 VAC.
Beyond that the power meters may not be rated high enough to make measurements...