stan2004 posted:I don't disagree. But the problem is whoever design O-gauge in the first place made the annoying decision to use 60 Hz.
Transformers are just too big at such low frequencies. I think the hit must be taken to convert to DC, then use a switchmode isolated converter running at 1 MHz (or whatever) so that the inductors/transformers can be proportionally down-sized.
The reason I was looking to do the isolation after the supercap is precisely the reasoning you are using, the inductors would be a whole lot smaller. I just haven't found a suitable design for the boost switcher that will fit and is cost effective.
JohnGaltLine posted:Just to throw something out there, do the boards that would require an isolated supply have somewhere else where input power could be tapped from rather than using track power? For example on a LionChief engine, filtered, rectified, unregulated, DC can be taped from the smoke-unit plug and shares common ground with the rest of the electronics package. If the legacy boards use a similar set up to power the smoke units, one could tap in there and share a common ground with the electronics that is already isolated from the input AC and chassis.
No offense, but this is a non-starter! The whole point here is having a PnP battery replacement. Hacking your $100+ RailSounds board to make it work isn't likely to be received well. Also, if you look at the modern RailSounds board, the only power supply is integral to the board, there is no convenient place to grab ground referenced power. This is a unit for people that don't play well with fine pitch surface mount parts!
