Phil's right - I was loose with the terminology to keep it simple. As item of DCC interest is the growing trend to add Keep Alive (or stay alive) super capacitor circuits to DCC decoders. The caps store power enabling locomotive to better run through dirty track. I bought one from TCS but haven't installed it yet - first up will be a locomotive used for switching like a Key H10 and or an AtlasO SW7. Both are very smooth runners but in rare instances stall on seldom cleaned industrial sidings.
Ed