Adding DCC Power Stations to an Atlas Master DCC System

For many smaller HO and N scale layouts, you will not need any other AC power supply (besides an Atlas Generator, Item #335) in order to run your trains and turnouts successfully with an Atlas Master DCC system; a single Atlas Generator provides all the power needed to run an Atlas Commander and power several locomotives at the same time (plus your turnouts). However, there are two cases where you may need additional power supplies.

1) One Atlas #335 Generator can supply only enough amperage to power the Commander and some (relatively small) number of locomotives that are to be operated simultaneously. In addition, this same Generator may also be used to power the twin coil or (by adding two type IN4003 silicon diodes for each slow-motion switch machine) slow-motion switch machines that are used on your layout. However, if you have a large number of slow motion switch machines and/or low-voltage light bulbs on your layout (e.g., lamps used for street lights or illuminating building interiors), or any other requirements for low voltage (e.g., 16 volts) AC power, you will need, in addition to the Generator, another power pack or transformer to power these items. One or more additional Atlas #335 Generators that is/are dedicated to this purpose will often suffice as a source for such extra AC power.

2) The second case where you could need additional power is when the current requirements for running trains on your layout exceed the capacity (2.5 amperes) of one Commander. To calculate your current requirements, you will first need to determine the maximum number of locomotives and lighted passenger cars (or cabooses) that you wish to run SIMULTANEOUSLY on your layout. Secondly, you will need to measure or estimate the current drawn by each of these locomotives and lighted cars. Finally, you must add up the currents drawn by all of the locomotives and lighted cars to be run simultaneously in order to get the total current required on your layout.

If your total layout current requirements exceed 2.5 amps, you can still use a Commander. However, you will also need to purchase one or more additional DCC power supplies, which are called either “Power Stations” (or “Boosters”) in DCC. Although Atlas does not currently offer DCC power stations, power stations are available from various other DCC system manufacturers. As long as a power station is designed to be compliant with all applicable NMRA DCC specifications, it can be used with a Commander. In order to use DCC power stations on your layout, you will need to divide the layout into a number of separate double-insulated electrical blocks, which are called “Power Districts” in DCC. One power district can be connected directly to the Commander; each additional power district is connected to its own power station. One Commander can accommodate a maximum of three additional power stations.

All power stations are connected to screw terminals C and D on the Commander and also to the track of the individual power district to which they supply power. The Commander sends a low level DCC signal to each power station, which in turn amplifies that signal and applies it to its own power district.

If you need additional information beyond this brief explanation of power stations and boosters, I suggest that you purchase the recent Kalmbach book "DCC Made Easy: Digital Command Control for your Model Railroad," by Lionel Strang. You will find a more detailed explanation of this topic on pages 14 to 15 of this book. This excellent book, among other topics, discusses how to calculate your power requirements and what gauge(s) of wire to use in wiring your layout. This book is available from your local hobby shop or directly from Atlas. (Price US $12.95 plus shipping.)