Enroute Controller described an emergency event when an IFR general aviation aircraft experienced an electrical failure [and] descended to land; all in accordance with standard procedures.

Narrative

Aircraft X checked on to my frequency level at 8;000 FT. His data block indicated 8;300 FT. He was opposite direction traffic for aircraft Y; southbound at 9;000 FT. Both aircraft were given the altimeter [setting] and I put a bubble on aircraft Y for better distance in a traffic call. I put the reported altitude of 8;000 FT in the data block of aircraft X. When the aircraft were about 5 miles apart; I issued traffic and aircraft Y responded. Aircraft X did not respond to the traffic call. Aircraft X then showed 8;300 FT and conflict alert went off. Aircraft X squawked 'radio failure.' I asked aircraft X if he was level at 8;000 FT and to acknowledge with an IDENT; [which] he [did]. After the aircraft passed; aircraft X started to descend and turn his aircraft in a circle to get below the clouds. I called for and was provided a D-Side. I told aircraft X the MIA in his area and had him acknowledge with an IDENT. I did not say; 'Low altitude alert' when I issued the MIA to aircraft X. He seemed to have enough to worry about and I didn't want to panic him. I would have if he was below the MIA. He squawked 1200 before going below 6;000 FT (the MIA in the area). I asked him if he was VFR and he acknowledged with an IDENT. I then read him the phone number for the Center; the [nearest] weather; and the ZZZ field elevation; runway configuration; and CTAF frequency. Aircraft X was lost on RADAR 4 miles southeast of ZZZ at 5;100 FT. Aircraft X called the Center and told us that he had electrical failure and that he was level at 8;000 FT until he started to descend and circle for ZZZ; [where he] landed. The pilot did exactly what he should have in this situation. I was also very pleased with the help provided in my area by other controllers and the CIC.