26-02-2020, 01:37 PM
(26-02-2020, 01:28 PM)ppppenguin Wrote: The relationships between voltage, light output and lamp life are very steep curves. At one extreme you can underrun a lamp by not very much and it will last almost for ever. At the other you have photofloods, heavily overrun and lasting just a few hours.
Which makes me think - optimising cost of photons!
At very low voltages, light output is very low, life of bulb infinite so can be discounted - but the lumens per watt is low. So lumen-hours per £ is low.
At high voltages, the tungsten lamp becomes much more efficient, so lumen-hours per £ of electricity gets much better - but the short bulb life can't be discounted. Particularly if labour cost of replacement is included. So overall financial efficiency is low again.
Somewhere in the middle, there's an optimum, but has anyone ever studied it and arrived at a conclusion (preferably in form of a graph)?
