P3D Re: MOtorola modifications

[fj834@xxxxxxxxxxxxxxxxxxxxx (Dr. George A. Themelis)]

>Where can I find a coupe of battery holders, and will the night light holders
>fit a decent wattage halogen bulbs?

If you go to Radio Shack you will find all kinds of battery holders,
light bulbs and light bulb sockets.  But putting them all together
is a little tricky.  First, you will have to decide on the voltage
of the bulbs.  If you go with 2.5 V bulbs then you will have to
decide on the current.  Popular screw base bulbs (available from
myself, among others) are rated 2.5V/0.8A.  Suppose you want to
go with these bulbs.  How many batteries should you use to power
these?  If you decide to only use one pair of batteries, then you
are putting great demands on that pair, called to supply 1.6A.
I'd recommend alkaline or rechargeable batteries, size D.  It
might be better to go with two pairs of batteries, one for each
bulb.  Then again I think D size is the way to go.  You might
consider 2.5V bulbs that consume less current. I carry halogens
2.5V/0.5A.  I think these are a better choice.

Most probably you will need an external switch to turn the light
on and off.  Where will this switch be?  Also, it would be nice
if you could power the unit w/AC (transformer or power supply)
so that you don't consume a lot of batteries.  You cannot just
pick any transformer and expect it to work well with your choice
of light bulbs.  You will have to consider current, in addition
to voltage.  I can help with this and also can make a custom
voltage regulated power supply.  With a regulated supply you
can easily control the light intensity and you can use many
different light bulbs.

Now, let's see... If you go with 2.5V halogen bulbs and select
a transformer or power supply (or just stick with batteries), the
original question remains... what if people forget to turn them
off?  The lower wattage most probably will be less of a problem
for your slides... but still... How about a timer to shut the
light off after a while?  As you can see... it can get very
complicated! :-)

BTW, the rotary viewers marketed by Jon Golden have some nice
features like adjustable illumination, timer to shut them off
if not used for some time, etc.

George Themelis