DIY light source for 10X10" enlarger.

"David Nebenzahl":
"Nicholas O. Lindan":
Office lighting systems usually supply a high (and usually bizarre - 347
volts anyone?) voltage from a central step-up transformer
Small correction: 277 volts. (It's printed on lots of ballasts.)

277 also. 120, 208, 220, 240, 254, 277, 347, 380, 415, 440, 480 and
600 are the common voltages.

415 for lighting is pretty rare, but I worked in a building
that was wired for it. The building super would swear at
length about it if anyone would listen.

The odd voltages are from 3-phase systems and are phase-phase and
phase-ground voltages: 120/208, 220/380, 240/415, 277/480,
347/600. 120/240 normally being a 2-phase pair.

The voltages relate either by 2 or the square root of 3 (1.73).

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.darkroomautomation.com/index2.htm
n o lindan at ix dot netcom dot com