I have heard that there are no companys producing 2-rail transformers? Any word on this?
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Could be. I've never heard 2 rail DC controllers called transformers. I've always heard them referred to as power packs.
With DCC you can buy an inexpensive transformer from most online electronics places to power the trains in 2 rail.
This is incorrect, Im sure someone will fill us in on what is available, personal I put together my own.
Stephen from Down Under (cTr...Choose the Right)
Depends on what you're doing. For "conventional" DC throttle operation, there are large scale 0-24VDC power supplies available that supply enough current to run O scale equipment. You can also use a variable AC transformer (like the MTH Z4000 or early Lionel ZW's) with a 25-amp bridge rectifier and DPDT switch to use as a DC power supply. I have no experience with tethered walk-arounds, so I can't offer any suggestions.
For DCC, a friend of mine is using Lionel 180-watt AC "Bricks" to power his NCE DCC system. These are a fixed 18VAC at 10Amps. MTH makes a comparable "brick" but I like Lionel's On/Off switch and circuit breaker.
If you want to "roll your own" there are plenty of step-down transformers out there that produce 18-24VAC on the secondary and plenty of circuits on-line for throttles for DC operation.
Hope this helps.
I use Variacs and transformers, fused and switched on both ends, with a Radio Shack bridge rectifier, a giant capacitor, and a red light to tell me when I have left it on. I have been in O Scale for 55 years, and have called these things transformers and power supplies interchangeably.
Building your own can be hazardous if you are not careful, but it is relatively easy and inexpensive - especially if you find surplus Variacs and step-down transformers.
O Scale DC is just like HO DC. Any DC power pack will word - - provided it generates enought amperage. Most modern models in O scale do not draw very high currents, so most any pack should work.
Dallee Electronics makes two specific power supplies for O scale. http://www.dallee.com/site_index.htm
GML Enterprses also makes a line of throttles that include 3 amp, 4 amp, and 6 amp capacities. The 6 amp will run any old high current O Scale.
http://www.thegmlenterprises.com/index.html
I have used GML throttles for about 20 years until I converted to DCC and I really liked them. I had 4 6 amp versions with memory for the mainline service and a 3 amp and 4 amp version for the yard and hostler. They are made in the USA and come with a 5 year warranty.
I use a "HO" MRC power-pack for my testing. The draw back for an HO sized power-pack in O scale 2 rail (straight DC) is the general need for more amps. Both scales use 12 volts DC. As a matter of fact most HO DCC systems push 16 to 18 volts AC to the rail, and a HO layout I have worked with over the past 15 years uses 18 volt DC power-packs for all the straight DC throttles! When you MU 5 or 6 old Athearns, you need a little more umph!
If you are running straight DC control on a small 2 rail layout with only one locomotive running at a time, a quality HO power pack will more than do. Of course, if you have other accessories, you will need more power packs to carry the cumulative load.
without going into a cobbled together hybrid setup, you can get a MRC Control Master 20 or an Aristo Power-Pack or an older Crest. All are about 10 amps.
all of these can be found online and at auction sites, some brand new.
an HO dc pack is fine for one small engine on a short piece of track but will not have the current behind it to drive a heavier train.
I can second the Controlmaster 20. It's what I use to do testing on DC only locos. You could also go with an MRC Tech 6.6. It's DC and DCC and puts out 6 amps, more than enough for the oldest 2-rail loco.
Just be sure to get something that provides plenty of power with a bit left over for those, shall we say, "special projects" that you might be doing in your "shop"...
Martin... you've been into my basement?
Originally Posted by PRR Man:
Martin... you've been into my basement?
Yup! Needed to borrow that machine that goes, "Ping!" to calibrate the Dark Matter Indicator again. I left a cup of sugar (I think it was sugar....) on the counter.
And another option is the MRC 6200. 18.5V DC. Recently picked up a like new one for $35. Works just fine.
Allan
that's fine... I'm completely out of dark matter at present. I have plenty of gray matter on hand but its really not working too well.
I bought myself the MRC Power "G" 10 Amp Pack:
http://www.modelrec.com/search...uct-view.asp?ID=1266
Easy to use and fun looking.
Still some around...
I have been using a Control 20 MRC to power my 2 rail NYC MTH Mohawk. There are at least two versions of this pack, the newest does not have a fan. At 18 volts I think it has about 5 amps.
I recently connected a Lionel ZW transformer and ran the same engine with AC. The ZW is rated at 10 amps and will do 20 volts. The additional "headroom" of the AC transformer made the engine run better. The sound is better and I found that I can doublehead two Mohawks and use smoke with no problems.
So now the decision for me is whether to buy a two track 10 amp power supply (Bridgewerks), or buy an MTH Z-4000 and run AC.
This is a difficult decision due to the cost difference between the Z-4000 and the Bridgewerks. I would not be considering a pack at all except I have several brass USH and other O scale engines that run on 12 volts DC.
Comments, especially re anyone who uses a bridgewerks?
I mostly run DCC now but flip a toggle to run straight DC from MRC Power G packs from time to time. The Power G packs are 10 amps and were about $160 per unit when I bought them from an online dealer in CA.
Hudson,
If you went to AC, would you put full blown DCS into your current DC only engines?
N&W
No. I would use a toggle to power only one track with AC when I run MTH DCS engines. The other side of the toggle would be a standard DC pack, probably one of my Control 20's. MY USH, Westside, and PSC O Scale engines would continue to be 12 VDC.
Since the MTH Track Interface Unit (TIU) has two separate inputs, ideally I would use a two track Bridgewerks power controller to put DC on two of my four tracks. (All tracks are DC powered now, but a Control 20 does not seem to have the power reserve that I believe I need to run MTH 2 rail engines and use all of their features.) If I used a two track DC Bridgewerks, there would be no need for a toggle and all engines I run would use DC. The Bridgewerks would replace two Control 20 packs I now use, one for each track.
From what little I have read, I like everything about the Bridgewerks but the price.....which is about twice what a MTH Z4000 would cost.
MTH TIU can actually operate on DC power but sadly their variable channels can only control ac voltage and not dc voltage for conventional equipment. I am waiting for the next version of the TIU they will include conventional dc voltage control I and all you would need is a DC power pack input to control both command and conventional 2 rail equipment. The MTH DCS command can control DC voltage as well as run on DC command (DCS) but is limited to 6 amps and only a single channel.
I've been reading with great interest since lately I'm trying to understand the electronics of model trains. Here is what I know or believe in ignorance.
Normal running of my Atlas engine pulls under 1amp. If I put it under load and push up the throttle I can force it to pull over 1amp to 1.5amp on the meter. So even though I never run more then one engine I assume 3 amp could run two O scale engines at best.
Now here is what I'm not sure about.
The MRC 6200 has two modes.
Mode I is 18.5VDC at 35 VA
Mode II is 14 VDC at 27 VA
I know that Volt-Amps are not the same as watts but the best I can figure is
Mode I can handle up to 1.89 amps (35/18.5) or one engine
Mode II can handle up to 1.92 amps (27/14) or one engine
Mode I has less amps but more volts (electrical pressure)
Conclusion we could run one O scale engine in Mode II. Would it run cooler then if you ran it in mode I?
MRC Control Master 20
Mode I Output: 0-20VDC 65VA Max, 16VAC; Total Output: 85VA
Mode II Output: 0-14VDC 56VA Max, 16VAC; Total Output: 75VA
Mode I can handle up to 3.25 amps (65/20) or two engines
Mode II can handle up to 4 amps (56/14) or two engines
MRC Power G has 10 amps
So does that mean it can run up to five or six O scale engines?
Please tell me if I'm wrong about this. I'm trying to put in practical terms how much power these packs have.
Even though volt amps are not technically the same as watts (they are for a purely resistive load), for practical purposes and the operation of our trains you can think of volt amps as equaling watts.
The cheapest way to get enough watts to run your DC trains is to take an AC toy train transformer - one that's already designed to operate toy trains, and rectify the output with a ten amp bridge rectifier. If you want to get fancy, you can add a double pole, double throw switch on the output side so you can reverse your trains.
You might as well go upwards of 100 watts and be done with it. Lower wattage, excuse me... lower volt-amperage, usually won't do the job. And too much cannot hurt, unless you have a derailment and weld something.
Someone can provide a wiring diagram, but it's pretty simple - unless everyone prefers it to be complicated. 
The MRC 6200 has a sustained output of 2.5 amps in either of the modes...for O and larger scales use it in mode 1
the MRC Controlmaster 20's came in two versions...the earlier version [85 va with cooling fan] had a sustained output of 5 amps, the later version [100 va without fan] had an output of 5.5 amps. Mode 1 for both types is the reccomended mode for O and larger scales.
Thanks for the info on the MRC packs. Since my post I pick up a used MRC 6200 from Ebay. Its a solid pack that's working quite nicely for me. I hooked it up with a walk-around throttle I got from Ken Stapleton.
http://www3.sympatico.ca/kstapleton3/821.HTM
With Ken's throttles the engine head lamps are on full brightness even at craw speeds.
