How to distinguish the projector lamp is DC or AC

 1. Through the model name discrimination

AC Projector LAMP: UHP HS HSCR UHE NSHA VIP OSRAM SYS GE 

DC Projector LAMP: SHP NSH UMPRD 

2.  Observation of the Burner 

First, communication is not positive and the negative poles of the lamp, so the exchange of lamp filament is a thread connecting.

While DC lamp filament in the middle part of disconnected, and a large head, it is positive; a head smaller, that is negative.