Separately, I think you're dodging a bullet when you tie together the 2 bridge rectifiers as indicated above. A bridge rectifier does not provide electrical isolation. It is electrical isolation that "allows" you to tie together the grounds of different electrical circuits. You dodge the bullet in this case because your input resistor limit the current but if, for example, Track 1 and Track 2 AC power are out-of-phase, then the diode(s) in the bridge rectifier will electrical short the two tracks.
Again, if this was all constructed with stuff you had and it works for you as built then so be it.
OGR being a discussion forum that is...
