GA SMA LOST ALL ELECTRICAL POWER AFTER TKOF AND HAD TO RETURN USING TWR SIGNAL LIGHT CTL.

Narrative

AIRPLANE AND ALL SYSTEMS (RADIOS; ETC) OPERATED NORMALLY AFTER START UP (ATIS INFO) DURING TAXI (GND CTL) AND RUNUP. WIND CONDITIONS WERE CALM AND RWY 5 WAS THE ACTIVE RWY. MINE WAS THE ONLY ACFT WAITING TO DEPART. TWR (118.50) CLRED ME FOR A LEFT DOWNWIND DEP. SHORTLY AFTER LIFTOFF AT APPROX 300' MSL SIMULTANEOUS WITH ATTEMPTED GEAR RETRACTION I NOTICED ELECTRICAL STATIC SOUND THROUGH THE HEADSET. THE LNDG GEAR HAD MOVED LITTLE IF AT ALL. I WAS UNABLE TO CONTACT THE TWR ON EITHER RADIO; TAKING THE ALTERNATOR OFF LINE TO A BATTERY ONLY STATUS STILL AFFORDED NO PWR. THERE WAS NO PWR TO ANY DASH INSTRUMENT INCLUDING GEAR LOCK INDICATIONS. THE ENG APPEARED TO BE OPERATING AT FULL PWR; BUT THE MASTER SWITCH FUSED (WELDED?) BEHIND THE PANEL AND COULD NOT BE MOVED. I MADE THE LEFT TURN TO THE LEFT DOWNWIND AS PREVIOUSLY CLRED AND BEGAN ROCKING THE WINGS IN AN ATTEMPT TO ATTRACT THE ATTN OF TWR PERSONNEL IN ORDER TO OBTAIN A LIGHT GUN LNDG CLRNC. THE TWR DID NOT OBSERVE THIS ACTION ON DOWNWIND. I DID NOT OBSERVE ANY OTHER TFC IN THE AREA AT THIS TIME. I TURNED XWIND BEYOND THE TWR AGAIN ROCKING THE WINGS ATTEMPTING TO GET THEIR ATTN AND THEN MANEUVERED BACK INTO THE LEFT DOWNWIND. ON THE DOWNWIND I WENT THROUGH THE EMER GEAR DOWN PROCS TO ASSURE THE LNDG GEAR WAS DOWN AND LOCKED. AGAIN THERE WAS NO TFC OBSERVED IN THE PATTERN OR ON THE ARPT TXWYS. UPON TURNING BASE TO FINAL I RECEIVED A STEADY GREEN LIGHT (THE ONLY LIGHT SIGNAL EVER GIVEN) FROM THE TWR AND I LANDED THE AIRPLANE W/O INCIDENT. A FIELD EMER TRUCK MET ME AT A RWY TURNOFF AND LED ME BACK TO THE RAMP. I WAS ASKED TO CONTACT THE TWR WHICH I DID IN PERSON. THE TWR SUPVR TOLD ME THAT AFTER I TOOK OFF THEY CHANGED THE ACTIVE RWY TO THE OTHER (RWY 23) AND I HAD LANDED ON THE WRONG RWY. I EXPLAINED WHAT HAD HAPPENED AND THAT I HAD NO WAY OF KNOWING THIS SINCE I HAD LOST ALL ELECTRICAL PWR AND HAD JUST DEPARTED THE THEN ACTIVE RWY 5. (I DON'T KNOW WHETHER OR NOT THEY BROADCAST THE RWY CHANGE.) WHEN ASKED WHETHER OR NOT I WANTED TO DECLARE AN EMER I WAS CONFUSED OVER WHAT TYPE OF OCCURRENCE ACTUALLY CONSTITUTES AN EMER. I PREFER TO VIEW THIS INCIDENT AS AN ABORTED TKOF/CLBOUT AND A PRECAUTIONARY RETURN FOR LNDG WITH A STEADY GREEN LIGHT LNDG CLRNC. REPAIRS TO THE ACFT INCLUDED REPLACEMENT OF THE MASTER SWITCH AND THE VOLTAGE REGULATOR.