Re: IR detector system, biasing of photo diode

Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

On 29-10-2024 20:59, Liz Tuddenham wrote:

Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
 

Hi
>
I am working on an IR detector that will guide a robot into a docking
station.

 
It sounds as though the problem could be solved easily and reliably with
a VLF magnetic field, rather than light.  Something along the lines of
the Lorenz blind landing beacon.  By using dot-dash modulation, the
receiver would know which side of the centre line it was on.
 
The only problem would be convincing your client that it wasn't radio -
but that sounds like a much easier problem than all the solutions so far
suggested.
 

I did look into that, but did not go deeper.
 
The Lorenz beacon was very ingenious.
 
The solution with a rectangular loop in the base of the docking station
worked well, but the client doesn't want that.

A ferrite rod aerial could be mounted so that it discriminated very
clearly betweeen two transmitting loops and it could be located on the
board with the electronics.  You could wrap it in a cardboard tube to
disguise it as a capacitor or something and tell the customer the system
works by a newly-discovered magic principle.

[I have made fake pre-war German capacitors to restore an historic Pathé
projector and they were almost indistinguishable from the genuine
article.]

Maybe it's time to convince him to look at other solutions again :-)

He is more of a problem than the electronics.


--
~ Liz Tuddenham ~
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www.poppyrecords.co.uk