Alt-BEAM Archive

Message #03034



To: "BEAM Mailing List" beam@corp.sgi.com
From: "Nicholas Smith" nik@resourcekt.co.uk
Date: Thu, 6 May 1999 09:46:56 +0100
Subject: [alt-beam] FLED SE Problems Solved


Hello all.
Alot of people have been sending mail to the list complaining that there
FLED SE/Photopopper doesn't work. Well I live in england and its near
imposiable to get voltage triggers over here so we have to use FLED's.

FLED SE's are maybe (IMHO) the swines of the BEAM world. They have a bad
habbit of locking up or not working at all due to the nature of these crappy
little devices.

Well I use um alot so heres what I do when something goes wrong:

GOLDEN RULE! Allways make you circuit work on a breadboard before you free
form it!

1. Solar Panel. - The solar panel has to charge the cap as quick as pos. for
a FLED SE to work. What happens is the FLED fires, sucks the power from the
cap QUICK! so try a large solar panel to keep the power up just that little
bit higher when the FLED fires.

2. Cap. - Get a real high quality one. Not the cheap ones about 20%+/- with
a very very low internal resistance. If you want to find the best cap in
your electronics catalouge the go look for one under the memory retention
cap section.

3. FLED. - Don't go for the super, hyper or ultra bright types there shite!
and make sure the FLED is completely covered from light.

4. Trans. - Its not the transistors fault. They allways work. But are rarely
connected right. I have sworn blind to myself that I have connected them
right only to swap the lead arround and my SE works.

5. Trans. - Did you check the lead pinout as I said above? Well do it
again!

6. That smelly 2.2k Resistor. If you get down to here and it still doesn't
work then replace that 2.2k res with a 5 or 10k trimpot and sit for hours
playing with the knob.

7. Motor efficency. - You should have a real good motor for a FLED SE
because there not very powerfull. Charge you cap on a battry and connect the
motor to it in series with the FLED and another diode. If it doesn't spin
then get a new motor or use a bigger cap.

8. Trans. - Go on give um another check.

Hope this helps. I get about 50% of my FLED SE's to work first time and 90%
of them to work at all.

Nik.



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