ACFT EQUIP PROB. INVERTER FAILURE CAUSING EFIS FLICKERING; 100 TO 150 VOLTS (OUTSIDE NORMAL RANGE) AND SMOKE. THE FLC TURNED OFF THE #1 INVERTER AS WELL AS THE TRANSFORMER RECTIFIER UNIT. FLC DECLARED EMER; COMPLETED APPROPRIATE CHKLISTS AND RETURNED TO LAND UNEVENTFULLY. RPTR SAYS THAT THEY COULD HAVE HAD BETTER COM WITH THE FLT ATTENDANTS.

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ON JUL/XX/96; I WAS AT THE CTLS OF FLT FROM FWA TO ORD AT AROUND XX00 CST. SOON AFTER TKOF FROM FWA; AS WE WERE CLBING THROUGH 8000 FT TO LEVEL OFF AT 10000 FT; I HEARD THE CAPT SAY SOMETHING ABOUT HIS EFIS. I LOOKED OVER TO THE L SIDE AND SAW THE EFIS FLICKERING. A FEW MOMENTS LATER I SMELLED AN ELECTRICAL SMOKE; BROUGHT IT TO THE ATTN OF THE CAPT AND CONTINUED FLYING THE AIRPLANE KNOWING THAT I WAS AT THE CTLS AND THAT WAS MY PRIMARY RESPONSIBILITY. AFTER THE L EFIS (PFD/ND) STARTED PROVIDING CLUES OF A MALFUNCTION; AND AFTER CHKING ITS OUTPUT WHICH WAS JUMPING BTWN 100 VOLTS AND 150 VOLTS WELL OUTSIDE THE NORMAL RANGE; THE CAPT TURNED OFF THE INVERTER #1. THE CAPT ALSO TURNED OFF THE TRANSFORMER RECTIFIER UNIT #1 WHICH SEEMED TO STOP THE SMELL OF AN ELECTRICAL SMOKE. THE CAPT COMPLETED ALL THE APPROPRIATE CHKLISTS. GIVEN THE CIRCUMSTANCES; COMBINED WITH THE TIME AND THE WX CONDITIONS; WE DECIDED TO DECLARE AN EMER AND RETURN BACK TO FWA. AT ONE POINT I TRIED TO USE THE AUTOPLT; BUT REALIZED THAT IT WAS INOP. I HAD TO HAND-FLY THE AIRPLANE WHILE THE CAPT DEALT WITH THE 'EMER AND ABNORMAL CHKLIST;' FLT ATTENDANTS AND ATC. WE WERE CLRED FOR THE ILS RWY 23 APCH AND LNDG. WE COMPLETED THE LNDG WITHOUT INCIDENT. UPON ARR THE CAPT PROVIDED EMER PERSONNEL WITH THE INFO THEY REQUESTED. THE NEXT DAY I CALLED MAINT AND WAS TOLD BY THEM THAT THE PROB WAS CAUSED BY THE #1 INVERTER GOING BAD. THEY EXPLAINED THAT THE INVERTER 'FRIED' ON US; WHICH IS WHY WE SMELLED ELECTRICAL SMOKE AND; IT WAS 'DRAINING A LOT OF JUICE' AFFECTING THE L SIDE OF THE ELECTRICAL SYS. IN MY OPINION; THERE WAS NOTHING WE COULD HAVE DONE TO PREVENT THIS FROM HAPPENING. I THINK WE DID A GOOD JOB DEALING WITH THE SIT. THE ONLY THING I WISH WE HAD DONE DIFFERENTLY HAS TO DO WITH THE LEVEL OF COM BTWN THE PLTS AND THE FLT ATTENDANTS DURING THE EMER. I THINK WE COULD HAVE DONE A BETTER JOB; EVEN THOUGH HAPPENED RELATIVELY QUICKLY. WE WERE AIRBORNE FOR ABOUT 15 MINS.