Re: Strange IR emitter problem

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Thu, 25 Oct 2007 10:43:36 GMT, nobody@xxxxxxxxxxxx (Dave Houston) wrote
in message  <472071a7.374640828@xxxxxxxxxxxxx>:

>Lewis Gardner <lgardner@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>>If changing the
>>placement of the IR receiver cannot solve this problem then the 291-80
>>CFL friendly receiver is your next step.
>
>Lewis,
>
>How much of a problem do CFLs create for IR receivers?

Legacy (i.e, not CFL) fluorescent lamps are particularly suspect. Modern
CFLs can avoid the problems demonstrated by legacy, conventional
fluorescent (not CFL) ballasts.

http://neptunlight.com/files/infrared_in_education.pdf
http://www.emsd.gov.hk/emsd/e_download/pee/infrared_interference_emsdweb.pdf

CFLs have benefited from the research on interference mechanisms and
frequencies and some recent ones have purposely have avoided the design
pitfalls that still affect older fluorescent ballast designs. Hence more
"IR-friendly" CFL designs.

http://www.neptunlight.com/files/IR-and-CFLs.pdf ends with the words:

"Many consumer IR systems, such as commonly employed in the TV and audio
industries, utilize the 33 to 40 kHz region for IR carrier frequencies.
[...] Many CFL high frequency electronic systems have already vacated this
frequency range, but this may not be feasible for linear fluorescent high
frequency ballasts.."

... Marc

Marc_F_Hult
www.ECOntrol.org