james knott gjaidadguarogerscom carlos e r wrote begin pgp signed message hash sha1 thursday 20080214 1307 0500 james knott wrote dont see transformer primary inductor anything _but_ reactive unloaded transformer inductive limits current low value lagging voltage 90 degrees load increases voltage current come closer phase transformer maximum load phase angle 0 assuming resistive load transformer problem case load neither switched calculate real power used need sample waveform least 15 samples per period voltage current multiply integrate root mean square rms need type cpu actually chip guess measurement gadgets appeared market quite replying transformer comment switching supplies transformers often used input incoming ac rectified filtered resulting dc used power switching regulator provides desired output voltages process results lot noise filtered power line load well shielded prevent interference use openofficeorg tue 05 aug 2008 205448 0500 opensuse ot much power pc really consume