Momentum for O

Not sure if that is an actual feature or not, could be just sales propaganda!

Sort of what Phoebe Snow is to Lackawanna RR, a sales pitch.

Lee F.

The momentum "feature" is built into the electronics in new command control locomotives.  It is not in the transformer.  

As far as I recall, no straight AC train transformer ever had a "momentum" feature.  Old toy train transformers are just that, step-down transformers with a wiper or roller moving across the secondary windings to vary the output voltage. 

Unsophisticated, simple, reliable.  Plus, they generally had a starting voltage of around 5v, probably due to the limitations of the transformers and the need for the electro-magnetic mechanical reverse units to cleanly cycle.

The momentum, as it were, in old toy trains was from the free-wheeling aspect of the drive mechanisms that could roll without power applied.

Rusty

Huh.  Who put a burr in your Hanes?  Momentum has been around in DC power packs for a good long time, works real well in my MRC tech II powered HO setup.

That's a real crackup about the  Phoebe Snow, possibly borne out of some kind of jealousy?

Pete

The command control systems provide some momentum control.

Locos with large flywheels on the motors help a little too.

For the most part, momentum will be controlled by your hand on the throttle.

When I was in N gauge I liked the momentum features for starting out, not for slowing down and stopping.  I still use my Tech II & III DEC power supplies on my Super/EZStreets (rectifiers removed from vehicles so I can back them up) but I don't use the feature there.  

There is no reason why one could not add a momentum feature to a modern electronic AC transformer.  I assume the manufacturers do not because it is already there in the loco if you use Legacy or PS3, so  it would only be a "feature" to those of us who run only conventional, like me - and most of those are very conventional, and don't want new features (or at least not enough do to justify the product development).  

The MRC Dual Power O27 270 Watt Transformer had this feature over 20 years ago, and they had a later AH104 100 watt version.  Both include braking and handheld walkaround capability. 

They both show up on eBay quite frequently at a fraction of the original cost and both operate in conventional mode quite well except for - you guessed it - MTH PS 1/2/3 trains.  They work fine with my MTH QS2+ equipment however.

And then, Lionel introduced TMCC for conventional trains - almost 20 years ago, which provides momentum control of all AC trains from any era with the addition of a PM-1 PowerMaster and a CAB-1 Remote to your existing transformer.  This combination provides for three levels of momentum and a programmable stall setting for additional control and station stops.

I may be wrong, but I believe that even Legacy momentum effects are controlled from the transformer/base-unit. I base this upon the speed graph action when momentum is in effect, and the understanding that there is no feedback from the locomotive to the legacy base (Not as of yet anyway.)  In the DCC world, you can program the CV registers on the chip to apply a momentum setting, but I don't think that this facility exists in the TMCC/Legacy world.

3 of these on ebay right now