Modulated DC test circuit for power installations - has mutually isolated DC and AC generators and diode connected across output terminals

摘要

The AC-modulated DC test circuit for electric power installations comprises a d.c current generator and modulating a.c generator, which together provide the required superimposed test waveforms. A d.c generator (1) has its output smoothed by an R-C Pi filter (7-9). The filter network feeds a limiting resistor (6) in series with a diode rectifier (4). The output of the diode is connected to the output terminals, across which the test specimen (3) is connected. Also in parallel with the output is the secondary winding of a transformer (2) with d.c blocking capacitor (5) in series. The transformer primary is fed with the a.c waveform. The diode serves to isolate the d.c source from the a.c waveform.