P3D Halogen viewer bulbs

[Project3D <Project3D@xxxxxxx>]

In a message dated 28/03/98  17:38:03, Dr. George A. Themelis wrote:

<<Bob Aldridge writes:
     
 >Once apon a time, there was a chap [...]
 
 Interesting story... thanks Bob!  But you didn't tell us who that
 chap was :-)
 
 >The designs have been imitated in a number of ways since - Dr T got the 
 >idea for Quartz Halogen lighting, secondhand from someone who had seen 
 >the conversions.
 
 Not really... Reel 3-D started marketing the 0.8A halogen bulb in 
 the USA.  >>>

Yes - they had seen this chap's conversion - or a derivative of it, and sought
out their own supplies of bulbs in a wider range of specifications than was
available at the beginning of the research. So did Dr T get the idea from Reel
3-D? Is that "secondhand" enough? :-) :-)

<<This bulb is taller than regular bulbs so it would not 
 fit in many stereo viewers, including the Realist red button.  I
 liked the bulb so I modified my viewer's base for the bulb to fit.
 I started selling these bulbs myself and modifying viewers for 7p
 and also modifying the base of the red button for the halogen bulbs.

Finally, I figured out how to make the halogen bulbs a bit shorter 
 (so no viewer modification is needed) and also how to "frost" the 
 glass envelope for diffused uniform light.  IMO, these frosted bulbs
 which have a screw base and come in a variety of ratings (2.5V 0.8A, 
 2.5V 0.5A, 6V 1.0A, 6V 1.1A - I stock all of them) provide the best 
 light for stereo viewing in a properly tuned viewer.>>

Agreed - all very important advances, for which you are due full credit. :-)
 
<< When using high current/low voltage bulbs in viewers, you have to worry
 about light flickering, which is caused by oxidation in the switch
 contacts.  I am now looking into installing a "microswitch" like Dave
 Burder has done in the modified Sterolists.  It is not clear to me how
 these switches work.  Is there a contact made?  If it is, why would
 these switches eliminate flickering? (as some people claim - I have no
 personal experience)
 
 -- George Themelis >>

Good question! I understand that the chap to whom I was referring also
installed microswitches. I think the flicker reduction in his viewers could be
as much due to the higher 6 volt electrics as to the microswitches. However,
the "action" of the microswitch will also help as the contact is made with a
degree of velocity not present with the original brass sliding contacts. Also,
microswitches usually have gold plated contacts which helps as well.

Isn't it nice to be posting about something other than what or where we should
be posting :-)

Bob Aldridge 


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