> > I bought out the last of the locally availaible little red things that
> > use nightlight bulbs and a bunch of the bulbs, so I am covered for red,
> > but I wanted an orange (Wratten OC) filter as I can see much better by
> > it.

> > The problem I have, is that here in Israel, we have been ahead of
> > everyone else in energy saving, CFL bulbs have been sold here, and used
> > by me, since 1997. That's good, but it has caused the demand and
> > therefore the supply of low wattage incadescent bulbs to dry up.

> > I found a few Chinese made 7-10 watt bulbs, but they only last a few
> > hours. I found a 15 watt bulb sold for refrigerators, but it has a
> > different base and I am trying to adapt it, but may not be able to get
> > those bulbs much longer and they are very expensive being made to
> > operate at 0F and below.

> > The smallest incadescent bulbs that are still common here are 40 watt
> > bulbs.

> > What is everyone else doing for safelights?

> I use 7 1/2 watt 120 volt incandescent lamp bulbs. Whereas most incandescent
> lamps are designed to last about 750 hours, these little ones are designed
> to last 1250 hours. I do not know if I have ever had one burn out. Now if
> you run them at 220 volts, their lifetime would be very short.

> My safelights came with 15 watt bulbs, and they did not seem to fog paper,
> but since the lights are slightly less than the 4 feet distance from my
> working surfaces, I thought it would be better to use smaller lamps in them.

> Incandescent lamps run much longer as their input voltage is reduced. You
> might consider putting a suitable resistor in series with the bulb to dim
> the bulb slightly and increase its lifetime. The trick is to compute the
> proper resistance. If you measure the resistance of the bulb with an
> ohmmeter, it will be very low, so you will get too low a value to put in
> series. It is better to calculate it. If it is a 22 watt bulb at 220 volts,
> the bulb draws 1/10 amp, so it is 2200 ohm with a hot filament. So you might
> try a 110 to 220 ohm resistor to lower the voltage. You might wish to use a
> 5 watt resistor.

> > Thanks in advance,

> > Geoff.

> --
>    .~.  Jean-David Beyer          Registered Linux User 85642.
>    /V\  PGP-Key: 9A2FC99A         Registered Machine   241939.
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