Dyson on You and Yours today.

[alan_m]

With a design like that you could have someone's eye out.

[Johny B Good]

Indeed but that's only for the 100W rated lamp. The optimum voltage increases with increased lamp wattage. There aught to be a family of voltage efficiency curves ordered by wattages for given design lamp life hour ratings somewhere but my googling failed to turn up such plots. Presumably, at some given wattage/lamp life combinations, the optimum voltage could land up at 120v and even 240v (I'd guess around the 250W/300W for 120v and probably somewhere around the 750W mark for

240v but that's only a guess).