Re: Lighted Viewers

[erker@xxxxxxxxxxxxxx (Greg Erker)]

[Our mail server problems caused this to hang up
for 3 days. Sorry.]

>I could add a Radio Shack project box to the back of the viewer with a
>light source inside it.  It would be somewhat ugly, but functional.
>What form of light source do people recommend?  I would want something
>that is reasonably bright, but does not drain batteries.  It should
>also be readily available, both so that I can acquire the initial
>setup, and so that spares (not just bulbs) are easy to get.  I'm a bit
>concerned that Halogen bulbs will run too hot.

  My viewer has an add-on light box.
Perhaps you could get similar wood to
what your viewer uses and make one.

  Inside mine has two Dr. T frosted
halogen bulbs 2.5V@xxxx bulbs. One
behind each slide chip. The diffuser
on my viewer is quite thick so I get
nice even light from the bulbs.

  The bulbs are wired in series and
wired through a microswitch that is
used as a set down switch to extend
the battery life when you set down
the viewer.

  As wired you need a 5V@xxxx supply
and I used an external battery pack
containing 4 C sized NiCads. It connects
with a 4 or so foot piece of 18Ga
speaker wire. Works fine and lasts
long enough for any viewing I've
ever done. Theoretically the standard
1.8Ah nicads would last over two
hours, extended by the set down switch.
Higher capacity cells are available
in C, sub-C and D sizes.

  It is roughtly as bright as my
Dr T red button. I don't have a
blue filter like Steve (which
absorbs some light) so I can get
away with 2 watt bulbs.

  You could also make an AC
powered power supply for your
viewer at a later date. For those
really long viewing session.
An LM317 voltage regulator could
be used to make a constant current
P/S. A pot could be used to have
variable brightness if desired.

Greg