A DHC8-100 Right AC Bus failed after takeoff so the flight returned to the departure airport.

Narrative

During receipt of the aircraft; the Captain and I reviewed previous logbook discrepancies of AC bus failure and cabin emergency lights cycling in flight. We discussed what seemed to be a pattern of unresolved electrical troubles. We departed the airport under visual conditions with a clearance to 8;000 FT. After completion of the After-Takeoff Checklist; the R AC Bus caution light and associated lights illuminated. We had just entered a scattered base layer of clouds at 5;800 FT. Outside temperature was +2 degrees C. The Captain decided that we would exit the icing conditions and return to our departure field. I informed departure control of our need to return for a normal landing. Departure gave us a vector and a descent for the visual approach. I then contacted our Flight Attendant and explained the situation and our estimated time of landing. The Flight Attendant informed me that the emergency lights had again cycled during climb. I made a PA announcement informing our passengers that the were would be returning for a normal landing. Lastly; I called station operations to advise them of our return and plan to unload at the gate. Returning to radio number one; I pulled the non-normal checklist. The Captain and I reviewed the list of affected AC services listed in the non-normal checklist. We configured the aircraft and flew a visual approach as previously briefed. After landing; I made another PA emphasizing that we were returning to the gate and would exit the plane normally. Caution panel and failure of associated services.