(a) No person who is serving as a full-time juvenile court judge shall at the same time hold the office of judge of any other class of court of this state.
(b) No person serving as a juvenile court judge after being elected juvenile court judge pursuant to a local law authorized by a constitutional amendment shall at the same time hold the office of judge of any other class of court of this state.
(c) Nothing in this Code section shall prevent any duly appointed or elected juvenile court judge from sitting by designation as a superior court judge pursuant to Code Section 15-1-9.1.