Re: Occupancy detection

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>That's good news.  I was worried because I didn't think either the sun,
>CFL's or plasma TV's modulated a carrier or worked on the Powermid
>wavelengths but managed to trash IR distribution just the same.  Like
>mercury in CFLs, I hate solving one problem by inducing others!  I guess
>I'll plunk down some bucks and buy a few of the kits:
>
>http://www.apogeekits.com/ir_light_barrier_mk120.htm
>
>and see what's what.  They're not very expensive.  Thanks for the input,
>Dave.

Those are Velleman kits and I found schematics although I did not find any
specs. If I remember how to calculate the frequency of an astable
multivibrator, the carrier frequency should be in the neighborhood of 5kHz
which should be OK with the Powermids but the acid test is to try one in
case I misplaced the decimal.

     http://www.velleman.be/be/en/product/view/?id=342937