Frustrated with IR repeaters that use RF links (like Terk)... ambient
RF noise too high for reliable operation :-(

It occurred to me that since I have a central "Great Room"
architecture, that makes for a wide open optical shot across great
expanses... as much as 60' per link... so a purely optical repeater
should work nicely... pick-up the IR from a remote and blast an LED
with an Ampere ;-)

Ceiling heights of 12' to 16' and door openings of at least 8' means I
don't have to contend with people getting in the way.

So now I need pointers on how to collimate/focus an IR beam so it
doesn't spread out too much at 60' range.

Ideas?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

"Jim Thompson" wrote in
message ...
So now I need pointers on how to collimate/focus an IR beam so it
doesn't spread out too much at 60' range.

Ideas?

Not so much on the collimation, but for testing you'll find that pretty much
all contemporary digital cameras will let you "see" the IR coming from your
LEDs. By holding a sheet of paper or similar in front of them as a target,
you should be able to get some idea of how collimated the beam is or isn't.

You probably already knew this, though. :-)

Jim Thompson wrote:
Frustrated with IR repeaters that use RF links (like Terk)... ambient
RF noise too high for reliable operation :-(

It occurred to me that since I have a central "Great Room"
architecture, that makes for a wide open optical shot across great
expanses... as much as 60' per link... so a purely optical repeater
should work nicely... pick-up the IR from a remote and blast an LED
with an Ampere ;-)

Ceiling heights of 12' to 16' and door openings of at least 8' means I
don't have to contend with people getting in the way.

So now I need pointers on how to collimate/focus an IR beam so it
doesn't spread out too much at 60' range.


You might not have to collimate much. Some remotes in hotels really pack
a punch yet must run legal power limits, and many from Europe as well.
Once in a Marriott I couldn't believe it. You could be in the bathroom
and switch channels. So I left the door open, walked down the hallway of
at least 100ft and hit "Channel Up" five times. Came back and sure
enough the TV was five channels up.

--
Regards, Joerg

http://www.analogconsultants.com/

In message , Joerg
writes
You might not have to collimate much. Some remotes in hotels really
pack a punch yet must run legal power limits, and many from Europe as
well.
As an aside, is there a legal limit for IR emission from remote
controls?

As for the original problem, rip apart a few CD-ROM drives and use the
lasers ;-)
--
Clint Sharp

"Jim Thompson" wrote in
message ...
Frustrated with IR repeaters that use RF links (like Terk)... ambient
RF noise too high for reliable operation :-(

It occurred to me that since I have a central "Great Room"
architecture, that makes for a wide open optical shot across great
expanses... as much as 60' per link... so a purely optical repeater
should work nicely... pick-up the IR from a remote and blast an LED
with an Ampere ;-)

Ceiling heights of 12' to 16' and door openings of at least 8' means I
don't have to contend with people getting in the way.

So now I need pointers on how to collimate/focus an IR beam so it
doesn't spread out too much at 60' range.

Ideas?

I use a 4" length of 20mm black delrin . Drill right through with 4mm drill.
Drill one end with 5mm to a depth of 7mm nominal to fit the led in with a
drop of super glue..

"Jim Thompson" wrote in
message ...
Frustrated with IR repeaters that use RF links (like Terk)... ambient
RF noise too high for reliable operation :-(

It occurred to me that since I have a central "Great Room"
architecture, that makes for a wide open optical shot across great
expanses... as much as 60' per link... so a purely optical repeater
should work nicely... pick-up the IR from a remote and blast an LED
with an Ampere ;-)

Ceiling heights of 12' to 16' and door openings of at least 8' means I
don't have to contend with people getting in the way.

So now I need pointers on how to collimate/focus an IR beam so it
doesn't spread out too much at 60' range.

Ideas?

I use a 4" length of 20mm black delrin . Drill right through with 4mm drill.
Drill one end with 5mm to a depth of 7mm nominal to fit the led in with a
drop of super glue..