P3D Simple rewiring of TDC 116 Stereo Projector

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

Lately I have become an expert in reworking TDC 116 projectors.  Common
problems: Slow (or non-starting motor), dirt, polarizers need replacement,
etc.  Regarding the motor, if you take it completely apart (it is not very
difficult) and clean it and lubricate it, it should be better but it still
might have a slow start.

I recommend a very simple electrical modification:  Rewire the projector so
that the fan always comes on when the plug is inserted in the projector. 
This way you will give the fan a bit of time to start properly, before
turning the lamps on and then it can stay on after the lamps are turned off,
to cool the projector.  I feel that this is important if you use 750W bulbs
and that's what I am using now.  To stop the fan you have the unplug the
projector, which is easy to do with the 116.

It is easy to figure out the rewiring.  No soldering or extra wires are
required.  Check the wiring system and you will understand it easily.  

The more sophisticated approach is to replace one of the 2-way switches
with a 3-way switch that will let you turn the fan on in the 3rd position. 
That's what I had done to mine, until this replacement switch started
having problems and then I went back to the simple approach.  If you decide
to install a 3-way switch, make sure that it is rated high enough to carry
the current (I recommend 20A if you are using the 750W bulbs or 15A with
the 500W bulbs).  Otherwise, follow the simple approach.

Note that the 716 does not have a plug at the projector (it is wired
internally).  Also, it does not have the problem of slow motor start
because it uses a different motor.  Finally, it does have a 3-way switch
that allows you to run the fan independently of the lamps.  But I still
love my 116 :-)

George Themelis


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