Flashing fiber optics in a turned wood vase

[Hal Mahon]

Objective: I am a new wood turner and would like to imbed the ends of a dozen or so fiber optic strands in the surface of a 4" to 8" diameter narrow neck vase. The other ends inside the vase illuminated by bright LEDs connected to several 5 to 10 sec timers to emit a brief flash of light. The effect should be subtle and idealy random. I want to intrigue the viewer who would be uncertain that he/she actually saw a small flash before the next delayed flash would occur from a different part of the surface. Access to the battery and electronics would be inconvenient so the device should have ultra low average current and hopefully months of unattended run time. I imagine the ends of the fibers to be small and inconspicuous when not flashing.

Need: Sources and specs for the chips, capacitors, LEDs, fiber optic strands and a recommended circuit.

I can solder together a circuit and assemble the other components once the parts are in hand.

 

[shaneshane1]

ideally random?

i dont think anything is completly random, there are a few IC's that you could use with 9 outputs or mabye more, 4017 decade counter IC it has 9 outputs that go high in order from 0 - 9.

you could just use something like that but it wont be random, it will repeat it self after the count, you will need a 555 for the pulse/time.

 

[RadioRon]

There are two circuits that come to mind for this. The first is a simple flasher circuit that runs for more than a year from a simple AA cell.

http://www.discovercircuits.com/DJ-Circuits/1vled3.htm

There is another flasher on Dave Johnson's site :
http://www.discovercircuits.com/H-Corner/led-flasher.htm

I built this latter one and found it worked very well. I think, though, that it can't work with LEDs needing more than about 2.5 volts, which would tend to exclude white leds. The battery lasted a very very long time.

The other circuit is the simple pseudo random sequencer such as on page 16 of this link:
http://www.cs.ucsd.edu/classes/fa05/cse140L/Lecture_1026.pdf

or in section 5 of this:
http://people.clarkson.edu/~ortmeyer/ee211/sequential%20logic/Fundamentals%20of%20Digital%20Electronics.pdf

One approach is to wire up several of those LED flashers with very different time periods, all quite lengthy but all independent of each other, and simply have each one feed a separate fiber. Would the result look random? perhaps.
Otherwise, another approach would be to have the PRN sequence generator drive an analog 1 to 16 Demux, with each output feeding a separate fiber LED. Perhaps each output would drive one of those LED flashers.

Of course, others will advise, rightly so, that the simplest hardware would have a PIC or AVR with quite a few outputs, each driving an LED. But then someone has to write a program to toggle those outputs randomly, which is not hard if you are PIC programmer.