Re: [photo-3d] View-Master Model D Bulb

["Dr. George A. Themelis" <drt-3d@xxxxxxx>]

>Went to Radio Shack and found a K222 Krypton 2.33 volts,
>600mA bulb that didn't need to be modified.
>
>Have you tried this bulb?

Yes, I have a lot of experience and have done lots
of testing of this bulb a few years ago.  I even
carried it for resale in my stereo viewer supply 
inventory.  But I was disappointed by its short life 
span and inconsistent quality that I do not carry it 
or use it any more.  

This bulb is designed for pen type flashlights using
two AA batteries.  That's why it carries a lower voltage
of 2.33V vs. 2.5V or 2.8V for some of the halogen bulbs.
A pair of AA batteries does not have enough "charge
capacity" to support the high current output (600mA).
So the voltage drops quickly and stays low.  This results 
in a decent life span for the K222 bulb but the batteries 
wear out pretty fast.  So you have a dim flashlight.

Now, if you use this 2.33V bulb with fresh size D 
alkaline batteries (which is what most stereo slide
viewers are or should be using), the bulb will work 
at 2.8V initially and the voltage will not drop as 
fast as with the AA batteries.  As a result, the 
life span of the bulb will be short.  Sometimes
extremely short, but it depends on how fresh your
batteries are.

As I said, short life span and inconsistent quality 
were a problem and I do not use or sell this bulb.
But other people appear to be happy with it.

I would rather use the 2.8V, 800mA bulb which has
a much longer life span. I have been using the same
halogen bulb in my Realist red button viewer for 2
years now.  The halogen bulb lasts 100 times longer 
than the K222 and it only costs 3-4 times as much.  
It is a real bargain, as far as I am concerned.

George Themelis