mrc power pack

Classic Toy Trains Forum
1

I found 2 old Tech II power packs made for HO and N scale. They have a variable DC, Constant AC (16.5 volts) and a constant DC (20 volts). I just have a few questions:

  1. The back says “Total 16 VA”. Does this mean 16 amp capacity?

  2. If so, does this follow the same rule as old ZWs of taking about 1/3 the amps away and in this case only using 10 or 11 amps, not 16?

  3. Will there be any problem running postwar accessories on the variable AC from this HO transformer?

  4. What about 022 switches at a fixed voltage. Do I have to use a phased or the same transformer as the track is powered by?

Thanks in advance!

2

You divide the VA by the voltage to get the availalble amperage. In this case slightly less than one ampere.

3

As you said, the AC output is constant; so there is no variable AC to run accessories from. If your accessories need about 16.5 volts, the constant AC voltage should be fine. Some accessories, but not all, will work on DC as well.

The voltage supply for the 022 turnouts can be DC or AC. If AC, it doesn’t have to be in phase with the track voltage and can even be at a different frequency. It only needs to share a common return that is the outside rails of the track.

Beware that the various outputs of this supply may not share a common terminal. This would limit you to using multiple outputs in applications (like the 022) that require a common to be connected to the track’s outside rails.

4

thanks for the info guys. I guess since I only have about 1 amp to play with per power pack I will be limited to using them for small lights in buildings, stations, etc.

Another thread had the amp rating for 1 022 switch at .5 - .81 when the switch is thrown. At 16 volts Im guessing the rating with be closer to the .81 rating. My layout with have 9 - 12 022 switches… so even if I split up 5 and 5 on each power pack, it will be too close of a call when you include the lamps for the other switches that arent being thrown.

Ill just have to phase in my KW with the 2 ZWs and have the 022s and some accessories run off of that.

On a posative note… I found TONS of my dads N scale trains in the attick. Maybe I can include 1 or 2 loops of N on a mountain instead.

5

It’s not a big deal, but, if you use the KW for turnouts and other accessories that use the outside rails for their return, having it out-of-phase with the other transformers will actually reduce the voltage drop somewhat; and there’s no harm in running it that way.