PLEASE HELP IDENTIFY

[jafomc]

THIS IS ON THE CHARGING END OF THE GATE OPENER BOARD, ANY HELP TO IDENTIFY, I THANK YOU IN ADVANCE, DAVE
THE PARTS READ SD109 ON THE TOP

[pebe]

I cannot find a data sheet for the SD109. It is probably a reference code used between the board manufacturer and his supplier. As it's in a charging circuit, the SD would seem to mean 'silicon diode' with the '109' being its ratings. The 'D5' etc on the board would appear to confirm that it's part of a bridge rectifier circuit.

See if you can establish what voltage and current the transformer gives, then look for a suitable diode in any of the many component supplier's sites.