#1 Hardware-Improvement

[Anonymous]

The Hardware-Application that is showed on the homepage isn't a really good example - it can easily destroy the LPT because of the currents that float when the relais is switched OFF.
You normally shout put a self-induction recuperation diode parallel to the coil of the relais:
/\ +5V
|
+---------+
< |
> Relais |
< |
> |
+--->|----+
| Diode
/
-| Transistor
\
|
|
-+- GND

I hope you can identify the schematic. But this is really elaborate - if you want to save parts and time, you should youse some ULN2803 -> an example, how to build this can be found here http://img403.imageshack.us/my.php?image=relaiskartekg9.png (feel free to use/modify/or do what you like with it :D) if you have further questions feel free to mail me: "moritz |at| grayther -dot - homelinux.com" or have a look on my homepage: http://thinksilicon.redprohosting.de <- where I have a schematic for a steppermotor-Control which really saves the LPT and also uses the ULN2803 (the site is in German but google might help you to translate ;-)

Bye
Moritz