Here we go again Joe. I'm trying to wrap my head around this so hopefully I'm not wearing your patience thin...
The DMM has a high input impedance and therefore should have minimum impact (meter loading?) on the measurements I was taking on the secondary of the Hammond Isolation transformer - right? Therefore the result was the voltage readings of 72 V and 20 V.
The analog meter with it's lower input resistance would have an impact on the measurements and act as a load - right? Thus I got the 0 volts reading.
After reading the information below am I on the right track? Without a substantial load on the secondary of the transformer the voltage readings I am getting with the DMM are a result of, and I quote, "under lightly loaded conditions, the reactive drop may not provide sufficient voltage reduction, or attenuation"???
Bulletin No. 7400PD9202
April, 1992
Milwaukee, WI, U.S.A.
Subject: The Performance Of
Shielded Isolation Transformers
It is the primary purpose of a transformer to transfer power, as faithfully as possible, from the primary to the secondary. Unfortunately, this often means coupling into the load input transients and other troublesome deviations from the ideal, clean power wave. A transformer couples power most efficiently at its design frequency, (usually 60HZ). Since the transformer reactive impedance increases with frequency, the higher order harmonics and high frequency waveform spikes are greatly attenuated with the transformer under load. This is simply because they are
dissipated across the XL component of the transformer impedance. However, under lightly loaded conditions, the reactive drop may not provide sufficient voltage reduction, or attenuation.
