Fiber Optic Trigger Lead for DRSSTC's
From: Tesla list
Date: Mon, 06 Feb 2006 16:14:09 -0700 - Subject: Working: A fiber optic trigger lead for (DR)SSTC`s
Original poster: Finn HammerAll,
I can now verify, that it is possible and easy to make a fiber optic trigger connection to any SSTC. I just completed one for myself, starting out with a transmitter driven from a 555 trigger generator: The transmitting LED is driven btwn pin3 and ground of the 555, with a 680ohm resistor to set the current. Nothing fancy, the transmitter is at the top of the box. Bypass caps below board. Closed, the box looks like this:
[link no longer good/f-hammer/fiberbox.jpg]
The receiver is active low, so I had to reverse it. At first I used a comparator, LM311 and it worked well on the breadboard, but I thought it better to have some hysteresis, the more the merrier. Since I could not find any schmitt triggers in an 8DIP housing, I wired the 555 as a schmitt:
link no longer good/f-hammer/donglesch.jpeg
I wanted the whole circuitry to fit into a 9pin Dsub shell, so I needed the 8pin
package. 15V is already available in the socket, Since I use Stephen Conners
PLL drivers, still not a lot of space left:
link no longer good/f-hammer/dongle.jpg
It all plays very well, here is a short video of one of my DRSSTC`s driven by the combo on each end of 100 feet of fiber:
link no longer good/f-hammer/fibertrigged.wmv
You guys remember how good it felt to make your first working electronic
project? Then you know how I feel now. I feel pretty damn good!
Cheers, Finn Hammer
Date: Mon, 06 Feb 2006 19:40:12 -0700 - Subject: Re: Working: A fiber optic trigger lead for (DR)SSTC`s
Original
poster: Steve Conner
Hi Finn, all,
That's great that you got a cheap fibre optic link to work. And 100 feet is an
amazing range, almost a safe distance for Ward's next DRSSTC ;)
If you're building more of them, you can wire my PLL driver to accept an active
low trigger input and do away with the 555, which might make your dongle a bit
less cramped. On the 9-way D input socket, instead of grounding pin 3 and
driving the signal into pin 2: Connect pin 2 to the +15v supply (on pin 5) and
drive the signal into pin 3.
Steve Conner
http://www.scopeboy.com/