Quote Originally Posted by EddyCurrent View Post
It says AC beside the socket and as Clive says the diode would indicate this is true.
Pin 1 gets used for all sorts, on my bob it is the charge pump. on others it is marked 'strobe' or 'spindle enable' or operates a relay for 'spindle forward'.
the diode is purely for reverse polarity protection. Too many mistakes would give me quality concerns...