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contrarotating gap


I had an idea the other day about how one could get a very high
breaks-per-second from a rotary gap without high RPM.  It looks like
this from the side...


              ___            ___
              |  |=====      |  |
              |  |           |  |
              |  |      =====|  |
              |  |           |  |
     |\/|     |  |           |  |     |\/|
-----|  |-----|  |=====      |  |-----|  |-----
-----|  |-----|  |           |  |-----|  |-----  
     |/\|     |  |      =====|  |     |/\|
      \\      |  |           |  |      //
       \\     |  |           |  |     //
        \\    |  |           |  |    //
         \\   |__|=====~=====|__|   //
          \\                       //
           \\                     //


             small rubber v-belts with
                1/4 opposite twists


                \\    \X/    //
                 \\   /\\   //
                  \\ //_\\ //
                   \\/   \//                                               
                    \| O |/   2 pulleys on a common shaft
                     \___/                                                

                      ^^
        motor drives this shaft


The principle is simple.  The 2 disks rotate in opposite
directions (though one could be stationary for 1/2 the BPS).
The number of electrodes (e.g. tungsten pins) is *different*
for each disk.  Strictly speaking, the numbers should be
relatively prime to each other; they have no common factors.

Here's an example...

The motor turns at 3600 rpm, as do all 3 shafts in the assembly.
One disk has 8 electrodes and the other has 9, all evenly spaced.
On each turn of the shaft there are 8x9x2 breaks, giving
518,400 breaks per minute, or 8,640 per second.

Notice the multiply in the formula.  If one disk had 15 and the other
16 electrodes, we get 28,800 breaks per second.

There are a lot of possible variations here.  Just remember to
keep the HV away from the motor(s)...

I expect the stray inductance could be a problem, as could the
precision of the electrode alignment, and the diameter would
have to be large enough to allow one gap to quench before the
next started, but there are no highly stressed components.

Anyone seen one of these?  Somebody probably patented it in 1903. :-/


      Loren Carpenter     |      Imagination is the true ground of being.
      loren-at-pixar-dot-com     |