Hi all,
I am currently using DC on an HO layout and have had issues with the speed control of a locomotive. I am using a duette controller, which I have been told is not the issue. The steam locomotive is travelling way to fast on the lowest setting I can make it go, and have added 375g to the first coach behind it with no success in slowing it down. As it is a small 7x8 foot switching layout, speed needs to be low. Any Ideas on how to slow the loco down?
Connect a resistor to the motor to cut down the voltage going to it.
A Resistor is good, I have had success with that, but in a thread elsewhere it was suggested to me to use diodes instead. Each diode drops the voltage by 0.6 volts. I used four of them like this:
Left rail________________________o______________________________
Motor
Right Rail ----|<-|<---------o-------|<-|<-----___________
That way there are two diodes checking the voltage to the motor regardless of which way the engine is running.
But if it is an old power pack, with a wire wound resistor for speed control, it may not work nice with newer engines which draw a fraction of the current of older locomotives. It will work perfectly with a resistive circuit such as a light bulb, leading you to think that it is working correctly, but a new locomotive will never even see it.
ROAR
The Duette is a rheostat power pack and this IS the problem. Modern locos draw too little power for an HO rheostat to work correctly, it doesn;t drop enough voltage, hence even at minimum throttle the loco runs too fast. An N scale rhoestat would probbaly run this loco just fine, but then the others would either burn it out or run too slow. The RIGHT solution is any sort of modern transistorized power pack, since they do not rely on the load of the motor to develop a voltage drop. Assuming you get one with sufficient current capacity to handle the older locos, a transistor pack will work with both old and new, and for any scale.
–Randy
Actually, the LION does have wire wound rheostats that do work with modern locomotives. I bought these in Japan in the 60s, and it must be just plain old good luck that they happen to work. But then they are not cheap power pack rheostats.
Today the LION uses a variable voltage 15 amp regulated power supply, but then LIONS are just plain different.
ROAR
What is a dc controller that is not too expensive yet can run new and old locos?
Any of the plastic cased MRC packs should work. Look at the Tech 2 and Tech 4 series of packs.
You can take a look HERE for a throttle which will run using either the AC or fixed-DC terminals of your current power pack. Excellent control and low-speed operation, and plenty of power capability to run multiple locomotives.
Wayne