Gilly
You are certainly correct that all the separate elements used in Protosound 2 for speed control existed before. But the patent was issued for the use of all those elements together for speed control of model trains in smph as well as integrating the speed control functions into the control of other features.
While it might seem that someone should have thought of it before, there apparently isn't any prior art for the application of such technology to speed control of model trains in smph.
The manufacturers of other command systems could certainly adopt a more accurate method of speed control along with a standard speed curve. Lionel has done that with legacy without any legal issues. It would be nice to see the NMRA DCC committee adopt a better measurement method along with a standard speed curve (or curves). But the DCC committee hasn't posted minutes of a meeting in years. I think they have bigger problems right now.
