I posted this on a few other forums with no luck.

I purchased 2 Ninco n-tronic controllers for the master track set. When you first engage the controllers or go slow the car motors have a loud electrical hum (vibration). The ninco cars are loud to begin with but the hum is very noticeable.
If I use the stock controllers the hum (vibration is not there). I am not sure what is causing this. The motors in the cars also get warmer when running the electronic controllers (is this normal?).

Both of the electronic controllers behave the same way. I can't imagine both are defective, but also don't understand the transformer type hum.

Any ideas?

Thanks,

Peter

Do the Electronic Controllers have sensitivity controls? Brake, Coast, Choke? What are the Ohm s on the Resister based controllers you are using?

It sounds like the controllers are 'pulse modulating' technology.
I have yet to see an HO design of this type sophisticated enough
to properly modulate the power at low speeds.This causes the
humming noise and extra heat.A few years ago I tried using Triacs
for a controller,the half wave pulses did the same thing.

Thanks for the replies,

Medic57, the electronic controllers have 11 power curve settings and adjustable braking. The stock controllers are 55 ohms.

tjettim, I received an email last night from an EE that designs controllers for model railroads and he also said it was because they are probably "pulse modulating."

I was just wondering if anyone had the same controllers and experience the same results. If this is normal I find it hard to believe that the distributors of this controller never experienced this.

Thanks,

Peter

All the Parma electronic contollers 'hummed' at low speeds.