SERIES AC FOR LOW-MERCURY CONTENT AMALGAM LAMPS AC Series emergency ballasts from IOTA were the first emergency battery packs to offer compatibility with today's low-mercury content amalgam lamps. Prolonged exposure to DC current can have damaging effects on these new compact lamp designs. AC Series emergency ballasts from IOTA protect the lamp by utilizing AC current while in the emergency mode. Operating the lamp with AC current rather than DC provides better overall performance with less distress to the lamp.