For this lamp and the mercury one-so wanted to see the turn off afterglow-the arc tube cooling down. Love watching the afterglow of my ceramic metal halide lamps when turned off. These have a following as plant grow lamps. 210W,315W,500W and 1000W. Give a beautiful light. Using mine right now for lighting. The afterglow of CMH lamps is sort of like HPS lamps.
That was including the losses. He mentioned that this lamp was supposed to be driven between the phases of a 3 phase supply (415V), so he was providing that by other means.
