? If? you look? at the? distorted waveform coming out of the FWB, FWCT, FWD, it typ consists of high, peak pulsed? currents.... when a C filter is used.? ? Like? 15-24A on peaks....and only? 1.5? to? 1.7 msecs in duration? at the bottom....as? seen on a scope.? ?Same deal on both the sec..and pri? of the? plate xfmr.?
To measure primary? AC current on the? plate xfmr,? ?you really require an? TRUE RMS? AC? Ammeter.? ? I hadn't? even thought of that anomaly, when? installing a? 0-150A? panel mount? ? AC? AMMETER.? ?
Did some research, and if using a NON rms ammeter? on the primary of a? single phase plate xfmr...with a FWB / FWD /? FWCT rectifier? and C?? filter, the non rms meter? can indicate as much as 40%? on the low side !
The plan is to compare the panel meter to a Fluke true rms clamp on ac?ammeter.?
Even with all that, you still have the issue of Power factor. True rms??Volts? X? true RMS? amps?=?True??VA power,? not??true?watts.??One of the ham fellows sent me a pix of his? spectrum analyzer display, depicting the odd? harmonics of the? 60 hz input...of a plate xfmr and FWB +? high? C? filter.? ?The? 3rd and also 5th? (180 hz + 300 hz) harmonic is the worse, then the 7/9/11+? drops like a rock.? ? With? full? wave rectification, the harmonics are always odd.? A half wave rectifier produces only even??harmonics.?
What? would be interesting is to measure peak AC current on the pri.? ? ?Then? compare to software results.?
Jim? ?VE7RF
