Observations from the relevant manuals.......
USA Trains Train Power 10, supplies upto 20 volts DC, dependedent on wire gauge which should be at least 20 gauge stranded, longer cable runs should be 18 gauge to prevent voltage drop.
DIAL-A-GAUGE, determines voltage and output waveform?????
PIKO 36220
Power requirements, 0-24V smooth filtered DC, power packs that produce an output waveform as a pulse or pulse width modulation will result in erratic and unreliable operation, and therfore should not be used.