Variable Momentum
TCS decoders support up to 6 different "Momentum Setpoints" that allow locomotives to accelerate and decelerate different across the speed range. We refer to this feature as "Variable Momentum." This feature can simulate long trains taking a while to get going (overcoming static friction). As the train accelerates, the speed changes more rapidly over time. From an observer's point-of-view, the train would accelerate slowly at first, to pull the slack out of cars quickly or to keep from knocking over your passengers, and then once moving would begin to accelerate at a faster rate.
Conversely, Variable Momentum can be set up to allow for rapid deceleration rates at "high speed," and then at low speed allow the engine to slowly creep to a stop. For deceleration, a longer deceleration rate (higher value) can be used at low speeds so the slack in the train naturally will be pulled out and the cars won't bunch up from coming to a quick stop.
Another possible application would be for instances where the decoders motor output is tied to something that is not a locomotive; for example, a windmill's blades. The variable momentum CV's can be used to give a "Soft Start" and "Soft Stop" to the blades on the windmill.
The Variable Momentum CV's are listed below:
TCS Non-Sound & WOWSound Version 4 Variable Momentum CV's
| CV Number | Description |
|---|---|
| CV3 | Acceleration Rate 1 |
| CV129 | Acceleration Rate 2 Start Speed |
| CV130 | Acceleration Rate 2 |
| CV131 | Acceleration Rate 3 Start Speed |
| CV132 | Acceleration Rate 3 |
| CV4 | Deceleration Rate 1 |
| CV125 | Deceleration Rate 2 Start Speed |
| CV126 | Deceleration Rate 2 |
| CV127 | Deceleration Rate 3 Start Speed |
| CV128 | Deceleration Rate 3 |
Visually, Variable Momentum could create a curve that looks like this:
