Quiet DCC Power Supply

[peteski]

There are couple types of eleicronic components which look like those ceramic disc capacitors you are familiar with.

One is the one already mentuioned here. PTC self-resetting circuit breaker. It is basically a type of thermistor - its resistance increases when it gets hot (conducting short-circuit current) and the resistance drops when it cools down.

Another one is a MOV surge protector.  It is a (usually self-destructing) varistor - its resistance is normally very high but it drops dramatically when exposed to its breakdown voltage.

[fire5506]

Depending on the scale you use the Digitrax PS2012 the amperage that is available.
 This is from the 2012 spec sheet,
The ‘G’ setting configures the supply to output 23 volts at 12 amps max.
The ‘HO’ setting configures the supply to output 18 volts at 15 amps max.
The ‘N’ setting configures the supply to output 13.8 volts at 20 amps max.

I went with 2 meanwell 10 amp 15v power supplies from Mouser part number 709-RS150-15 at $25.05 each. They are adjustable from 14.25 - 16.5 volts. There is no fans on these power supplies. If I lose one I'm not down totally. I'm using them for HO.

Richard