In article <4648v2$rs7@cmcl2.NYU.EDU>, akl4188@is2.nyu.edu says...
>Troy T. Hall (troyhall@kingsnet.com) wrote:
>: Any ideas on what one can do about not having a darkroom timer? I >: have plenty of electronic parts around, but I don't seem to have >: schematics

I use an audible beeper - beeps once a second while the enlarger light
is on (on foot switch - great for dodging and burning) - based on a
Radio Shack piezo beeper. Stock, it beeps twice a second, but doubling
one of the two large capicitors inside (experiment to find which)
causes it to beep at a more useful 1 Hz.
Hope this helps.