Does anybody know when ECM Compspeed controllers were introduced?
There is a thread on rec.models.railroad where Mikes Train House (MTH) are
sueing the DCC suppliers for using back EMF control in their modules. They
claim they patented back-EMF control in 1980.
I moved to the US in the late 1980s and I remember people using Compspeed
I feel sure they were around in the 80s so if they did they might have a
fwiw I have a photocopy of a page from elektor date july 77
which has a diagram of a back emf controller so the concept
was common knowledge back then , but I think that patents
only deal with implementations of ideas , so they may be
claiming a particular implementation ie circuit config ...
I did one on my vic20 a long time ago (dont remember the date :-)
I wont rant about the problems of patents , but they do not
encourage innovation IMHO and as for the american patent office ,
it is said they will patent anything ... now where's that application
for water :-)