Hi George, I found that posting after I responded to Bob. It clears up some but let's further clarify by example. I have a great looking S-2 steam turbine 6-8-6 #671 from 1948. Engine runs strong but the tender whistle is anemic. Could pull out whistle and use tender to house electronics with leads to the engine. Tender is plastic so it won't impede RF signals. Simple enough to isolate engine from center rail pickup.
Tender track power can be converted into 15 volts (or up to 24 V DC per spec) using full bridge and power regulator and routed to the power inputs of the BR board. Motor outputs from the board go to the AC motor armature and, through a second full bridge rectifier, to the field part of the AC motor. This bypasses the electromechanical E-unit entirely and allows for reverse but voltage is dropped 1.4 V due to 2 diodes. Not sure how speed control would be implemented as AC probably has different EMF characteristics than a DC can motor (BR uses back EMF for speed control presumably). But you'd have bell, whistles, lights (if isolated from chassis and routed to tender), future sound upgrades, robust electrical power by using a backup battery (dirty track), direction, could add electrocouplers, etc. Not sure how any sound linked to speed, such as synchronized chugging and consisting, would work though.
This sounds like a pretty good deal to get more usability out of some less used locos that run on conventional AC track (the track could be set up as AC or DCC). What am I missing?
1) On BRT's website they say clearly "Do not use the board with O gauge Universal motors." I would like to know why? Are motor outputs of the current board sensitive to feedback from those motors?
2) They also say to isolate the motor and lights from the chassis or DCC-ready locos (my S2 turbine is DECIDEDLY NOT DCC-ready). Some AC motors' housing (field stator?) are not isolated from the chassis I believe so that may pose a challenge. But why, electrically, is this a requirement?
Satisfactory answers to these two questions would be great.
Kirk