Several functions of a computer should be accessible even without keyboard and monitor. With the help of the described IR receiver you can interface every usual remote control transmitter with your computer. Software for Linux can be found in the LIRC project (Linux Infrared Remote Control).
As receiver I used a Siemens SFH 506, I got the 36kHz version for DM 3.90
at Segor-electronics in Berlin.
The two closer pins (1,2) are GND and +5V the more distant pin (3) delivers
the output signal. The SFH 506 needs under one milliampere, so it could
be powered from the serial line without problems.
The SFH 506 is not produced anymore, you can use the SFH 5110 or the Vishay TSOP 1736 instead.
In difference to the description in the LIRC project I changed the power supply dimensioning. Herby the receiver also works at a notebook or PCMCIA adapter which both deliver a lower voltage at the serial interface. Moreover it is now guaranteed that the maximum allowable voltage at the receiver inputs will not be exceeded. Of course you can use an 78L05 voltage regulator as an alternnative.
The circuit fits into a D-Sub enclosure, with the sensor at its front side.
The code learning for the used remote control and the creation of the command file is described on the LIRC homepage. I'm using the remote control for example to display several informations on a small LCD display , to recall messages on my answering machine or to switch TV stations.