Question for the 2 rail old timers

Walthers made a throttle/power supply called a Marn-o-Stat.    I think it was fading by the 60s and more transistorized stuff came in.   It was rheostat based.     Another source was to use a Variac.   I don't know their intended use, but they were considered great model RR transformers.     A lot of guys bought rheostats and wired them to transformers bought separately.    I don't know when heavy bridge rectifiers came available.    I started using rectifiers from Radio Shack in the 70s (when they still sold parts).     Dallee Electronics also made some power supplies but I think again they emerged in the late 70s or 80s.   There were some people that probably still used 12 volt car batteries with Rheostats - very smooth DC.

However, there are many reasons why most of us have moved on to more modern power supplies.    Plain rheostats did not give very fine control.    Plain transformers tended to not provide smooth operation as the loads increased.    We went to transister throttles as from Dallee and then more advanced throttles such as the 6 amp version from GML.    GML still makes very good throttles.    And then we have DCC now which adds even more flexible and good control.

Those old locos are well built and will run better with a modern DC or DCC power supply.   If you want to stay straight DC, I recommend GML.

I use autotransformers, step-down transformers, a couple of circuit breakers, an on-off switch, a dpdt switch for reversing, a Radio Shack bridge rectifier, and a giant electrolytic capacitor.  In 1950 I had a really good Mantua transformer with a huge selenium rectifier, but the auto transformer, or Variac, is really the only way to go unless you like transistor throttles.

I have three of these things and parts for a fourth.  I have taps for switched DC and AC, and have used them to drive the MTH DCS system with both.  I use old MRC meters and WWII bomber switches.

Simple and inexpensive.  The most expensive part is the Variac, and you need the smallest size reasonably available - about 3" diameter or so.  Find a friend who knows electricity, and be careful around house current.

My first O scale power supply purchased around 1973 was a five amp dual Marnostat power pack from Walthers.  It worked well but after several years the big rheostats crumbled apart and I junked them but saved the transformer.  That assembly had a huge selenium rectifier.  As Bob said above, it is relatively easy to purchase a transformer, 25 amp silicon bridge rectifier and connect them to rheostats or a transistor throttle.  My son built my transistor throttles from an article in a Kalmbach electronics book over 30 years ago and they are still going strong.  I have no intention of using DCC on my simple railroad.  The trains run.

Joe

I also have no intention of using DCC on a small layout with 2 locomotives and only one used at a time.  I thought about building my own but wanted to see what was used back in the day that was commercially made.   I figure the 2.5amp max is the bare minimum with the old AN open frame motors.  Mike

Hi Mike,

Although you asked about 'store-bought' throttles, and got some answers about such beasts, plus a few suggestions about building your own 'power pack', here's an easy, and fairly inexpensive, way to make your trains go.

Not knowing how vast your knowledge of electricity is, here's a little primer:

A 'transformer' will either boost or reduce the AC voltage output, depending on which way you hook it up.  It must then be rectified to convert the AC to DC, so you don't let any precious smoke escape from your motors (which, sadly, only happens once). 

A 'Variac' feeds the transformer with variable AC, which ultimately varies the DC to the track through a DPDT (double-pole, double-throw) switch to effect reverse. 

Lacking a rectified transformer, you CAN use one of the 'booster' type of battery chargers (short burst output of up to 50 amps), controlled by a Variac with excellent results. 

Lacking a Variac, you CAN control the juice TO the charger with a (good) household light dimmer switch, and get the same end result. 

Here's the basic setup: 

House voltage (110) to the dimmer. 

From the dimmer to the charger. 

From the charger to the DPDT switch. 

From the DPDT to the track.

An added bonus with the above rig is that, with a few homemade accessories (easy), your 'throttle' can be used as a resistance soldering rig, which will become one of your most cherished tools if you like to build things.  Ideally, you'll use a Variac, but a good quality light dimmer switch will do the job until you replace it with the Variac.

I hope all that helps more than confuses...

Mark in Modesto

That makes more sense on how a variac is being used to me, since those are a bit before my time as a model railroader.   I would think with just one engine being used, a 2.5amp transformer would be fine.  Mine layout will be a switching layout.  

Well, at the risk of sounding picky, if you connect a TRANSFORMER (AC output) to your track and try to run your All Nation locomotive, you will fry the motor instantly...you want to use a POWER PACK (DC output). 

Yes, a 2.5 amp current will probably run the thing, but why limit yourself to being at the edge of it's capability.  Lacking a booster battery charger, just use one with (about) a 10amp output, and you will have plenty of juice to run the old stuff, some of which will only barely move with 2.5 amps. 

Know that the charger doesn't PUSH it's amps...it let's the operator PULL the amps he needs to do the job.  A circuit breaker between the throttle and the track will keep you safe, and kick out if the current drawn (amps) exceeds the limit of the breaker, which will be chosen by you to cover at least 150% of the load your loco needs. 

For example, if your loco draws 4 amps to start with a 'tonnage train' (all the cars it will haul), you'd probably want a breaker which would kick out at 8 amps (which would indicate a problem somewhere).

I know you cant feed AC to the track, not my first go around with older trains or any trains by any means.  Building my own might be a bit over my head, thus looking for one already built or commercially produced.  I can handle replacing the old 110vt line cord on an older throttle/transformer so it can be safely used.  I think Scintilla made a higher amp unit.  Need to get my old Walthers catalogs out.  I know I have seen a Marn O Stat unit that was around 10 amps.     Mike

Probably the best one to get is a newer MRC Control Master 20 with the walk around controller being my layout is a switching layout. 

In the early sixties there were a LOT of car battery/rheostat combos or Lionel transformer/rectifier combos in use.

I had two Marn-o-Start (Marnold Co.) lever-style rheostats (as opposed to rotating knob) in the 60s, but they weren't really very good. These days I am using a system from GML that has given excellent service for about the last eight years, along with GML's digital volt/amp meter (you can toggle between displays). This set up replaced a Dallee "Engineer," which was good quality, but was housed in a large stand-alone metal cabinet with sloping front that was very hard to integrate into the front panel of my layout.

You could use a Lionel or American Flyer postwar transformer and run the output into a bridge rectifier. The only "modern" component would be the rectifier.

You could also use an American Flyer rectifier on the output of the transformer.

That would be very old school, have plenty of power, and be easy to do.

http://www.ebay.com/itm/Americ...9:g:kIAAAOSwcUBYFU2J

My guess is that those AN locos do not draw more than 2.5 amps.    Check the current draw with a meter under load.    You might be pleasantly surprised.

I do know the F7 with its CLW drive and extra ballest will overload a Bachmann Magnum transformer in about 10 min or less.  Did that at the little circle layout set up at the Indy meet a couple months ago. But I wont be continious running for some time.  Probably just switch with the NW2 I am buying.  In all reality, I should swap the F units for a couple more NW2's as they would fit my layout size and needs better.  I do have a "thing" for the Harbor Belt.    Mike

According to the amp meter on my railroad, the AN switcher draws about one amp, dual powered with the original open frame AN motor,  nowhere near 2.5 amps.  The F units, dual powered and weighted draw about 1.5 amps.

Joe

@rrjjf posted:

According to the amp meter on my railroad, the AN switcher draws about one amp, dual powered with the original open frame AN motor,  nowhere near 2.5 amps.  The F units, dual powered and weighted draw about 1.5 amps.

Joe

So... what would be the amp draw on an AN steam engine? Being "single-motored", would the draw be similar to the AN switcher?

Mark in Oregon

Dallee makes a handle held tethered throttle that you provide the power supply.    I had 3 of their older versions that I ran off an AC Lionel transformer.    They were fine and were transistor throttles.   I had to build a case for mine, but I think they sell one in a case now.

While it is nice to want to run old school, the old control systems were very crude.    the locos not so much.   an AN switcher with a nice paint job stands  up quite well today.    And those units do run well.   They ran pretty good with the old controls, but will run much smoother with a new transistor type throttle.   

Unfortunately GML has folded its tent.    I used their throttles before I went to DCC.      I loved them.    they had a 6 amp throttle that would hold the voltage at 12 volts, until the draw reached 6 amps and the breaker opened.    Most DC throttles and power packs do not do this.    As the current draw (amps) increase, the voltage will drop to hold everything at a constant VA (Volts * AMPs) rating.    For example, a throttle rated at 20 VA means it will deliver 2 amps at 10 volts, or 1.67 at 12 volts.    At 2.5 amps, it will deliver only 8 volts.     That is the way the VA rating was explained to me.

Another variant on the battery/rheostat might be to use a battery charger (not a trickle charger, one with heavier output). I had an HO layout when I was a kid, it was running off a battery charger connected to a rheostat. You could use a modern rheostat or you could find an old powerpack with a bad transformer (powerpack meaning the kind of thing used to run HO or prob even O gauge trains back  in the day) and use a battery charger to give it the 12-14 v dc it needs. If going the powerpack route just make sure that it was designed to handle higher loads, prob 2.5A would be enough for you needs (ie that the rheostat can take the current).