TRANSFORMER FOR 2-RAIL LOCOS

Something rated at 12 volts (or perhaps more), and at least 2 amps, more if your equipment is older/stouter. Depends on what you are powering.

You would not use a transformer to run 2-rail O scale equipment. Transformers output AC current. 2-rail locomotives use DC current.

You need a DC power pack, not a transformer.

The MRC Thottlepack 9950 is rated at 7.5 amps.  Should be able to handle most 2-rail O, modern or ancient.

Rusty

For my DC 2 rail portion:

There are a dozen power packs on my layout.  For DC track power I use Dallee Engineer power packs and Dallee Yardmaster.

Also there are quite a few high mileage MRC control Master 20 units plus some MRC 6200 and MRC 9500 power packs.    Also use them for TT opertion.   I keep back up power packs for the MRC products.

Dallee power packs IMO are the highest quality units one could use.   Just hard to find.

DC operation is not growing so product development and product delivery are waning.  I am converting my DC engines to battery R/C on an ongoing basis.  DCC is not in my plans.

A power pack is merely a transformer with some circuitry added to convert AC to DC.   The simplest is a simple bridge rectifier.     These used to be available at Radio Shack (when such a place existed) for a couple of bucks and had high ratings such as 50 volts and 20 amps and more.    There were various sizes.    You could simply wire the AC terminals from your transformer into the A-C poles on the rectifier and then DC was available on the Plus (+) and minus (-) poles.

modern power packs generally have more circuitry to give finer control of the output and sometimes provide electrical boosts at low speeds.     Quite often they have potentiometers instead of rheostats and these control output through transistor circuits.

Even simpler than the rectifier is an old 12 volt battery with a rheostat - not too many people want to do that anymore!

I have this for my DC operations.  Not new, but at 10 amps of capacity more than capable of doing the job.

@prrjim posted:

A power pack is merely a transformer with some circuitry added to convert AC to DC.   The simplest is a simple bridge rectifier.     These used to be available at Radio Shack (when such a place existed) ...

Jim,

They still are, technically, but it probably won't help here.

Radio Shack didn't disappear.  It still exists.  It's downsized but still in business.

The same bridge rectifiers are still catalogued, although unfortunately they're currently listed as "Out of Stock" because of the global parts shortage.

As of today, it's probably better to go with a power pack as a result instead of making your own, or you can try to order your bridges from Digi-Key or Mouser instead.

Mike

@Mellow Hudson Mike posted:

Radio Shack didn't disappear.  It still exists.  It's downsized but still in business.

Interesting....  I looked for one using their store locator -- took me to a vacant lot where everything was bulldozed clear and then to a Wendy's,   Hard to stay in business like that,

@mwb posted:

Interesting....    Hard to stay in business like that,

Couldn't you say the same thing about most LHS's?

Brick and mortar is too expensive nowadays for many traditional businesses, including trains and electronic parts.   There's no difference.

Mike

I totally agree, a modern transitorized throttle is better than a simple bridge and rheostate by leaps and bounds.     The rheostat would just run the DC trains like the old postwar Lionel stuff.    I was just pointing out that underneath the fancy name, there is still a transformer.

Easiest fix is the 10 AMP MRC G power.  Can run multiple engines with ease.  Also have the MTH DCS system hooked up to it.

It's hard to believe that a full-wave rectifier would be the victim of the world-wide supply chain fiasco.  Just buy 4 diodes on an auction site for a buck and make your own.

@Arthur P. Bloom posted:

It's hard to believe that a full-wave rectifier would be the victim of the world-wide supply chain fiasco.  Just buy 4 diodes on an auction site for a buck and make your own.

Arthur,

You're right about trying an alternative approach, in fact several attempts may be needed.

The shortage, though, is not hard to believe to those of us who are living it.  Are you currently involved with purchases of electronic parts on a day to day basis? I currently have several projects at work currently on hold for months already because of shortages of common parts.

Many, many things are affected, all the way from fancy microprocessors down to diodes.

Mike

@LV_DPR posted:

Easiest fix is the 10 AMP MRC G power.  Can run multiple engines with ease.  Also have the MTH DCS system hooked up to it.

I use the 10 amp MRC G power also. It has worked well for me for 15 years or so. Unfortunately, I went through a few lower amp power packs before I arrived at the 10 amp version.

Although I have no doubts about the G gauge MRC 6200, I have found that any of the "lighter gauge" packs I have are perfectly adequate for can motored diesels:  (i.e Weaver, Red Caboose), and will also run my All Nation Ten Wheeler(s) with their big, open- frame motors.  These include the MRC Control Master V (and an early "Dual Pack") as well as my Heathkit unit, which is pretty "light weight". As I once posted on the S scale page, this Heathkit can handle my Enhorning F unit and American Models RS3 just fine, but will overload and shut down if I try running any American Flyer locos with their "universal" type motors. FWIW.

Mark in Oregon.

@LV_DPR posted:

Easiest fix is the 10 AMP MRC G power.  Can run multiple engines with ease.  Also have the MTH DCS system hooked up to it.

Agreed.  I have used one for years, whenever I want to run a DC locomotive

I prefer small Variacs, surplus step-downs, Radio Shack bridges, circuit protection both ends, Ammeter and Voltmeter, and a pair of toggle switches.  I usually throw in a giant capacitor to smooth the ripple, but a lot of folks like the ripple - acts like pulse power, I guess.   I fuse it for around ten Amps out, and maybe one in.

I have the Bridgewerks 25 amp, 30amp, and even a third one too. I bought them for my G scale. I have to believe they'd work great for O scale DC too.

However, I run AC with MTH DCS on my 2 rail layouts.