DCC Ready, DC Power packs

[taz-of-boyds]

Mf5117,

As to why you specifically get 24.6 V AC on your meter I would need to do some research as to what the square-wave like DCC AC signal does to a conventional multimeter set to read AC (or one of the other guys can chime in).  But generally in my distant past experience when I recall, a multimeter expects a sine wave for an AC signal as in wall power, not a square wave as in DCC.  Unless you are using the "DC loco on address 0" there should not be any particular amount of DC voltage on the rails.

Charles

[DaleDe]

Exactly true. It is AC square ways (although they are not really square). A simple multimeter on reads a DC current to make the needle move. It is rather slow to respond compared to the AC switching that is going on so it only averages the current out to zero. There is a great big resister in line with the meter to calibrate it for voltage but it is really current it measure. To get it to read AC they put a diode in series that blocks all the AC in one direction so the meter can read the average of the voltage going in the other direction.

As you point out the numbers only really work for AC sine waves and they are just numbers fudged to read correct based on the sine wave. They really measure average.

Dale