IDMT129

I have a MRC 6200 that I use with my G Scale Lilly Belles (Accucraft and Harland). It certainly will work and has more than enough voltage to run the Schuco at faster than "scale speed."

I wouldn't use the MRC 6200 on large Schuco layout like mine because, as I wrote before, it helps to have the higher voltage to get the engines to coast through any dead spots and clean them off. Even the PIKO transformers which put out 20V don't do as well at the "track cleaning" job as the 24V LGB 50081. But on a smaller loop you can keep all the track clean and you don't have to run around a big layout when the monorail stops, you will probably be fine with the MRC 6200.

We had an American Flyer train set when I was young. I then got into Aurora slot cars in my middle years. My Adult hobby spun out of reading books and magazines about Disney. I bought Micheal Broggie's book on Walt's Trains and found out about the Schuco Monorails in the E-Ticket Magazine. I joined the Carolwood Club which developed a lot of G Scale and the H/O Lilly Belle. I started got my first Schuco Monorail in about 1997 and bought some HO trains as "decoration" for the monorails so I have both G and HO trains.

KarlG

Sorry have no technical experience to add. Just had to say this monothread is making me want to pick one up. I'll be on the look out for a second gen. red.

There is one on Ebay, or check on the link that Karlg posted for the Schuco Monorail site. i have already begun to use him as a resource and friend. he has a few good items i will be needing once mine arrives, and he is very open and helpful. Don't be surprised if there are Schuco MrK II monorails in the near future which are very accurate!!

I did a quick try with my MRC 6200 and the Schucos and the result was not great. You can probably get the trains to run a scale speed, but unless the tracks are very clean to begin with it will be tough to get them running and to coast through dead spots (once, again for a small loop you might be able to manage). One of the "secrets" of running Schucos is that by all evidence (multiple people testing their transformers) is that the Schuco transformers put out higher voltages than it says in the manual.

Below is a chart I generated about 4 years ago for various transformers including the Schuco, LGB 50081 and MRC 6200. I measure the RMS voltage and the mean as the old Schuco put out a pretty poor DC with a high amount of AC ripple on it where the more modern LGB was pretty pure DC. I measured with No Train (open), with the train running with the wheels spinning but not on the track (no-load -- I couldn't get a rational reading while, and with the wheel stopped (full load). I couldn't get a rational measurement with the train running normally but is is probably about half way between no-load and full load.

What you can see is that the original Schuco put out much higher voltage than the 17V the manual says (this has been confirmed many times by different people). The original transformer also has very high ripple and a high internal resistance (voltage dropping under load).

As you can see from the chart, the LGB is not very far off from the Schuco in terms of the voltage with "no-load" and the "voltage at "full load" when set at 24V. I don't think you will have any problems with the engines running them at 24V for at least a short time, but it will likely shorten the bulb life if you do it all the time.

Shown below are the waveforms of the various transformers as measured by an oscilloscope. As you can see, only the LGB puts out fairly pure DC until it is under heavy load (and then only a small ripple compared to the others). With the engine running (and probably consuming about 0.1A) there is virtually no change in voltage (plotted in black so you can see it against the red open line) with the LGB but the other transformers show more of an effect.

As you might expect from a 1960's era Schuco transformer, the "DC" has a high AC component to it. But somewhat surprising (to me at least) with the late 1990's era transformers, only the LGB 50081 puts out nearly pure DC. The MRC 6200 transformer is pretty much half wave rectified with the MRC9000 being better but with still with a lot of ripple on it even with a light load (train engine running but not on track).

LGB transformer it is then! Thanks for taking the time to show me that info.

Karlg, one minor correction to your write up, the rectifiers all appear to be full wave bridges but only the LGB has filter capacitors to flatten out the wave. Any MRC with a "pulse" switch will be full wave rectifier until set to the pulse position when the rectifier is half wave.

Additionally the old Schuco is probably a variable resistor in series with the transformer, the series resistance in the transformer and the variable resistor will add up. The other units are probably transistor throttles where a FET replaces the variable resistor to control the voltage to the tracks for lower series reistance.

I think a filter capacitior would help all of the other power supplies but you need to install them prior to the direction switch so the polarity is always the same. The exictment of popping the plugs on electrolytic caps is not needed here.

To run the 7 monorails you have from one supply, you need at least 3.5 amps of current and the full voltage, at the 25 volts that would be 87.5 VA.

I run my single trains with an MRC throttle pack, it is built like the old Schuco with a full wave bridge and series variable resistor. The peak output voltage is just over 15 VDC and though it says it is a 30VA output when drawing more than an amp the voltage drops down to 12 VDC. I have used it for two power units on a small loop when comparing speeds but I'd have to provide a track power feed every 3 to 4 feet on a larger layout and still I could run two trains at most. Better to get a second power supply and run two trains on seperate rails the way the Schuco was designed.

IDMT129, You're right the LGB is the best off the shelf supply for the Schuco.

Jazzfan -- Big oops, they are going to take my MSEE back for screwing that one up on the half-wave rectifier . The LGB does have a very good smoothing filter.

You guessed wrong on the Schuco transformer. I had to take one apart to replace the selenium diode (the silver thing with the black ends at the top of the picture below -- in 2004 I was able to find a new old stock one) and while I had the back off, I took pictures. As you can hopefully tell from the photo below, Schuco used a multi-tap transformers. I not sure, but I think there are two wire wound resistors (tan rectangles at the top and bottom of the picture below) that are used for current limiting. All I can see is the 5uF capacitor which is probably acting as the filter. Thus the original transformer only has a few voltage steps with the rotaty switch selecting both tap on the transformer and reversing the polarity of the DC output from the rectifier.

I at most run 2 trains off a single transformer (on the bit loop with block switching I run 4 trains, two on each transformer). The trains nominally draw 400mA at 24V so the 1A transformer handles two trains reasonably well with a bit of margin.

Interesting, the series resistance goes up with each voltage step, the opposite of the variable resistance. I have often thought that a Lionel or American Flyer transformer would make a good G power supply with big rectifier and direction switch.

I would think many have the needed power output. At the Lionel service station I used to work for, we'd put those 25A, 50V rectifiers in the big 275W ZW transformers for the whistle controls.

For the Schuco monorails, you may need to be picky. Flyer transformers top out at 15V. Lionel variable outputs commonly go from 6V to 18 or 20V, depending on the model. Some have 14-24V variable ranges. However, V- and Z-types have four independent variables of 6-25V. V is 150W, Z is 250W. Note that these are different from the VW and ZW models.

It might be worth noting that transformers with whistle controls have an additional 5V secondary winding, which could be added to the variable output. However, since most transformers with variables topping out at 18-20V start at 6V, the range would thus start at about 11V.