I am not familiar with this controller, is there a longer code number associated with it or can you post a picture of it?

Carim

Before I continue I should confess that I don't have any inside knowledge of these things, so there will be a fair amount of conjecture in my comments.

Firstly, though, I think we can elimniate your wiring being in heavier gauge cable from suspicion.

According to the information on page 6 of this Trainini article : Trainini this controller is not a PWM type, which was my first thought for why locomotives are running hotter.

Perhaps we can now explore under what conditions they are running hotter? Do you observe this with controllers set to maximum speed or with them set to match locomotive speed? If it's the former, then it's likely that the controller just outputs a higher maximum voltage. If the latter, though, it would suggest that the Trainini article is incorrect and this controller is a PWM design or that it features high ripple and peak voltage. This might be due to the mains being half wave rectified within the design, but could also be due to a fault with the controller - a faulty smoothing capacitor, for example.

I see the Lokmuseum description makes mention of infinitely smooth control, which implies it uses a potentiometer as it's control element. A potentiomenter consists of a strip of resistive material with a movable mechanical wiper which makes contact with it. Depending upon where along the strip the wiper is positioned, this controls the effective resistance. Anyway, it doesn't take much by way of muck build up or oxidation to affect the contact of the wiper with the resistance track and that usually results in intermittent contact as the potentiometer is adjusted. In an audio product this can cause a scratching noise when you change the volume, but in a speed controller it results in erratic behaviour of one sort or another. If you can get access to the potentiomenter you can probably fix this (at least temporarily) by squirting in some contact cleaner.

It has to be said that controller design varies enormously. Some are very spohisticated and some very crude, although performance doesn't necessarily follow sophistication. The Gaugemaster design, for example, is really quite basic but works incredibly well!

With that in mind, it's hard to say if the hot running of your locos is a feature of the controller design or if it is faulty.

All the best


Chris

Personally, I woudn't worry about the current (Amps) too much. It's not really a feature of the controller itself and is typically difficult to measure accurately.

Given the option, I'd be most interested in looking at the voltage waveform which is much more telling than the reading a multimeter will give you (which will be averaged in some, likely unspecified, way) but that's a bit specialised for most modellers.

Cheers


Chris