Re: Help with fiber optic cable/control

[Bryan Andersen <bryan@visi.com>]

I was in one of those mega home stores and noticed a 
fiberoptic based yard lighting system.  It used large 
diameter fibers (.5mm or so) but it is a possible source.  

Edmund Scientific also sells optical fibers.  Kindof spendy.
http://www.edsci.com/

As for what I'd do:  Clear plastic or glass rod.  Drill 
a hole in the case so the rod can go through it.  
Bend/rout the rod so it has a clear view of that area 
where the arcing will happen.  Place you photo sensor 
on the other end of the rod.  One problem with fiber 
optics is getting enough light into the exposed end.  
Glass fibers are very small.  The plastic or glass rods 
can have a much larger end so it can more easily gather 
much more light.

Highly polished tubes also work as good light conduits.  
To maintain the polish you will likely need a window at 
each end.  

One thing I would be worried about is temperature.  All 
glass fiber bundles I know of are clad with plastic.

As for the photosensor, I'd use a phototransistor.  They 
are very easy to hook up to logic circuits and can be 
tuned to see very little light.  I bet the arcing will 
output enough light you won't have to use a photodiode.


KilowattA798@cs.com wrote:
> 
> I now have a mech. control to adjust brush timing in my lite wt. 12in.geeeeee
>  motor used in the Current Eliminator.
> 
>                              I now have a need for a fiber optic cable or
> cables and a switch of some sort to act as a way to disable the controller
> ect.  in case of brush arcing. This also may lead to another way for me to
> control the gear motor that rotates the brushes.
>                      DENNIS KILOWATT BERUBE Looki ng at the 7s
> currenteliminator.com

-- 
|  Bryan Andersen   |   bryan@visi.com   |   http://www.nerdvest.com   |
| Buzzwords are like annoying little flies that deserve to be swatted. |
|      "Linux, the OS Microsoft dosen't want you to know about.".      |
|   -Bryan Andersen                                                    |