Hi All, I have an Inertia controller I built many years ago and a couple of engines notably a Proto GP18 and a Mantua 4-6-2 with a can motor have problems when I “put on the brakes”.
When I make a “brake application” with most locos, the loco starts to slow down and I can control a stop fairly well. With the two locos in question, perhaps because of low current draw or some other factor I am not aware of, the train can keep running as though there is no braking effect then suddenly slow down despite “heavy applications of the air”. I know this “runaway effect” can replicate some train braking actions but I would like to know what might be the cause of this happening.
We have a similar system on our club layout. The brake effect allows the locomotive’s motor to drain the voltage off of an electrolytic capacitor and bring the engine to a slow stop.
As you have surmised, the low current draw of newer locomotives with can motors counteracts the braking effect of these types of throttles because they don’t discharge the capacitor fast enough.
[#ditto] You knew the answer before you posted the questions. A few of the better transistor throttles have a setting for “low current draw” locomotives. It changes the resistors used in the various brake settings.
Hi all, thank you both for your replies so far but to make the task difficult, no I did not know the answer before I posed the question.
I have many other can powered locos with Mashima and Sagami motors as well as Dutch can motors in three of them. My Proto diesel switcher does not “run away” nor does my can motored Mantua Mike, yet they have identical systems.
It may be I need a “fix” of some kind or perhaps an alteration to the circuit or the loco to enable it to follow similar performance curves and I genuinely need to understand why with your help of course. Do I need some form of “dummy load” in the circuit or do I place some resistive component in my two locos which “misperform” or have I made a design booboo with my controller?