= Einfacher Power-Switch =

Ziel ist es, einen simplen und günstigen (aber skalierbaren!) Powerswitch zu bauen.
Es sollen also von einem Rechner aus andere ein- und ausgeschaltet werden. Solche Geräte
können als integrierte Netzwerk-Lösung gekauft werden, sind dann aber leider
sauteuer. Deshalb bastle ich hier an einem Ansazt, so ein Ding selbst zu bauen.

It's my goal to build a simple and cheap (thus scaleable!) power switch. This way,
you can switch on or off different computers through one controlling machine. You can
already buy such beasts, even with network connectivity, but they're damn expensive.
Because of this, I'm tryin' to build my own one...

== Shift Register ==
Ich denke, daß hier ein 74xx595 am einfachsten zu benutzen ist:

I think the 74xx595 is best to use here:

{{{
|----v----|
|O1    Vcc|
|O2     O0|
|O3      A|
|O4    Oen|
|O5    LCl|
|O6    SCl|
|O7    Rst|
|GND    SO|
|---------|
}}}

|| O0 .. O7 || Parallel output pins; these connect to the "signal in" of the relais drivers ||
|| GND      || Ground ||
|| Vcc      || 5V Power Supply ||
|| Oen      || Output enable - Connect to Vcc ||
|| A        || Serial input - Connect to Parport ||
|| LCl      || Latch Clock (commit parallel output of shift register to parallel Output pins O0..O7  - Connect to Parport ||
|| SCl      || Shift Clock (Shift serial input) - Connect to Parport ||
|| Rst      || Reset - Connect to Parport ||
|| SO       || Serial Out - chain  devices through this ||

== Driver Stage to Drive One Relais (to which a V230 Jacked is Connected) ==
{{{
                                +12V
                                 |
                              /--V--|
signal >----+---|R 120 Ohm|--|BC547 |
            |                 \--v--|
            |                    |
            |                    +--|Relais|----+-------|GND
            |                    |              |
            |                    \--|1N4148<|---/
            |
            +---|R 2k2 Ohm|-----------------------------|GND
}}}