RJ-45 ethernet to optical and back

[Jamie Morken]

Hi,

I was thinking about cutting an RJ-45 cable and hooking up the
differential transmit wires to an LED (through a differential to single
ended transformer) and then hooking the differential receiving wires up
to a photodiode through another differential to single ended transformer
and aiming them at eachother! Would something like this work? I am
sure that amplification would be required also, and everything would
have to be fast enough for 10mbit operation at least, but it seems like
a quick way to make a wireless internet without any special software
required as it would essentially just be a repeater..

cheers,
Jamie

 

[Ian Stirling]

Jamie Morken <jmorken@shaw.ca> wrote:

Hi,

I was thinking about cutting an RJ-45 cable and hooking up the
differential transmit wires to an LED (through a differential to single
ended transformer) and then hooking the differential receiving wires up
to a photodiode through another differential to single ended transformer
and aiming them at eachother! Would something like this work? I am

No.
You need a fair bit more than this, unfortunately.

sure that amplification would be required also, and everything would
have to be fast enough for 10mbit operation at least, but it seems like
a quick way to make a wireless internet without any special software
required as it would essentially just be a repeater..

This can be done, and you can get pre-built modules that do it, but
it's a bit more than just an LED/transformer.
At minimum, you've probably got to regenerate the data bits.

 

[Rene Tschaggelar]

Jamie Morken wrote:

Hi,

I was thinking about cutting an RJ-45 cable and hooking up the
differential transmit wires to an LED (through a differential to single
ended transformer) and then hooking the differential receiving wires up
to a photodiode through another differential to single ended transformer
and aiming them at eachother! Would something like this work? I am
sure that amplification would be required also, and everything would
have to be fast enough for 10mbit operation at least, but it seems like
a quick way to make a wireless internet without any special software
required as it would essentially just be a repeater..

For 5mm you mean ?
You need some optics to get decent beams for whatever
distance you were thinking at. Then you also have to get
rid of the ambient light, unless you want to use it only
in the dark. And then there are the impedances. A LED is
somehow not good enough and a photodiode neither.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[Andrew Holme]

Jamie Morken wrote:

Hi,

I was thinking about cutting an RJ-45 cable and hooking up the
differential transmit wires to an LED (through a differential to
single ended transformer) and then hooking the differential receiving
wires up to a photodiode through another differential to single ended
transformer and aiming them at eachother! Would something like
this work? I am sure that amplification would be required also, and
everything would have to be fast enough for 10mbit operation at
least, but it seems like a quick way to make a wireless internet
without any special software required as it would essentially just be
a repeater..

cheers,
Jamie

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