N Scale Controllers

[GreenDiesel]

Long story short, I may have been using controllers that have too high a voltage for N scale. I had been using an older Tech II transformer that has an output of 20VDC and this may have burned out the motors of two of my locos.

I have ultra basic Railpower ones but they have an output of 15VDC -- is that still too high? What transformers would you recommend for N scale? 

I live in Canada but our products should be similar to the US's.

Thanks in advance.

Rob

[Charlie B]

Hi Rob

      Wikipedia says a maximum of 12 volts for N scale. 
Charlie

[GreenDiesel]

Thanks! My lowest ones have 15VDC, so I might be on the lookout for new controllers.

[ezdays]

Thanks! My lowest ones have 15VDC, so I might be on the lookout for new controllers.

I wouldn't, you should be able to use what you have. At 20 volts, your engine should be flying off the track. I run N scale and use a Tech 4, and I can set my throttle range to whatever I want. The Tech II doesn't have that feature, so you can pick the highest voltage you want to run at and either mark that spot or keep the knob from going past that spot. 

Rather than measuring the voltage, what I'd do is run a train with some cars to load the engine, then slowly move your throttle until it reaches the maximum speed you want, then mark that spot. Be aware that most controller open circuit (no load) output voltages will drop with a load. I have a couple of old MRC controllers, on one I can set my max output, but when set to max (26 volts), it will drop to 20 volts when I load it. I also have a dual throttle N scale controller that is pre-set for a maximum of 12VDC out, however, open circuit, one output reads 26.3 VDC and the other 25.4 VDC. They need a load for an accurate reading, and will drop closer to 12 VDC with a load. I also have a couple of 3-12 VDC, 5 amp variable supplies that I bought on Amazon recently that have a stable output regardless of the load. I'm using those for lighting.

I have to admit, I don't run trains that often, I like the building aspect of model railroading, but I think my advice should help you.

[jim currie]

voltage is not the big issue here as don said it can be varied the big problem is the fact that teck2 was only a half wave rectifier you need to use or get one with a full wave rectifier the motors will run cooler and last longer, the other motor killer is week magnet's.
Jim

[ezdays]

voltage is not the big issue here as don said it can be varied the big problem is the fact that teck2 was only a half wave rectifier you need to use or get one with a full wave rectifier the motors will run cooler and last longer, the other motor killer is week magnet's.
Jim

Regulation is an issue, especially with a half-wave rectifier. Regardless, there is always ripple to contend with, where the  peak voltage is higher than the DC output (kind of like bumps in the DC). I put an oscilloscope on the output of that single output MRC Controlmaster X just to check the ripple and there was none at no load, but as I remember, around 1 volt at full output and half-load. Those two 5 amp supplies that I got from Amazon are what is called switching supplies and don't require a transformer. They are very well regulated with little ripple and have a digital readout. The downside is that they cannot go below 3 VDC. Great for accessories and lighting but not running trains.

[jim currie]

don I still have one old military power supply that has 15 volts at 10 amp's at 9 amps there is no ripple with a o scope but it has a filter cap that is 40000 mfd.
Jim

[ezdays]

don I still have one old military power supply that has 15 volts at 10 amp's at 9 amps there is no ripple with a o scope but it has a filter cap that is 40000 mfd.
Jim

Hard to fit one of those caps in a Tech II case

[GreenDiesel]

Thanks for this feedback above. Interesting. I did buy a Kato PowerPack today that is supposed to be suitable for N scale. I didn't want to risk burning out any other locos. Interesting that two of the locos that died were both from the same British manufacturer (Union Mills) so maybe they can't cope with 15-20 Volts.

[GreenDiesel]

Thanks! My lowest ones have 15VDC, so I might be on the lookout for new controllers.

I wouldn't, you should be able to use what you have. At 20 volts, your engine should be flying off the track. I run N scale and use a Tech 4, and I can set my throttle range to whatever I want. The Tech II doesn't have that feature, so you can pick the highest voltage you want to run at and either mark that spot or keep the knob from going past that spot. 

Rather than measuring the voltage, what I'd do is run a train with some cars to load the engine, then slowly move your throttle until it reaches the maximum speed you want, then mark that spot. Be aware that most controller open circuit (no load) output voltages will drop with a load. I have a couple of old MRC controllers, on one I can set my max output, but when set to max (26 volts), it will drop to 20 volts when I load it. I also have a dual throttle N scale controller that is pre-set for a maximum of 12VDC out, however, open circuit, one output reads 26.3 VDC and the other 25.4 VDC. They need a load for an accurate reading, and will drop closer to 12 VDC with a load. I also have a couple of 3-12 VDC, 5 amp variable supplies that I bought on Amazon recently that have a stable output regardless of the load. I'm using those for lighting.

I have to admit, I don't run trains that often, I like the building aspect of model railroading, but I think my advice should help you.

Thanks, Don -- this is helpful. Will keep experimenting, even though I had already bought a new controller today.

[ezdays]

Thanks, Don -- this is helpful. Will keep experimenting, even though I had already bought a new controller today.

I would do this, even with your new controller. I would hope that it will allow you to set the max voltage from your throttle, but do it by speed rather than measuring the output or what's on your controller's throttle label.

[GreenDiesel]

Thanks, Don -- this is helpful. Will keep experimenting, even though I had already bought a new controller today.

I would do this, even with your new controller. I would hope that it will allow you to set the max voltage from your throttle, but do it by speed rather than measuring the output or what's on your controller's throttle label.

Thanks, Don!