sorry for reposting on this, my earlier post on a simple 2 channel IR TX rx volume control met with no response, something i said? or have i found a gap in AACs otherwise supberb knowledge?

i found this http://www.maplin.co.uk/Module.aspx?ModuleNo=220034&C=SO&U=strat15 on maplins should be coming today,
but what about this for simplicity http://circuitdiagram-schematic.com/motion-detectors-with-infrared-sensors/
presumably this and a second circuit of different frequency would provide a 2 channel control? range ?
i would appreciate any comments.

can i please us this post to thank L chung for his reply on advertising volumes in which he says that the content of these broadcasts precludes the use of an avc, however the are other considerations where an avc helps,
the avc in theory anyway, should increase the level of quiet programmes,
many of my favourite documentaries are broadcast in analogue which tend to be a lot quiter, the avc certainly helps here, and i certainly dont need to readjust volumes when changing channels as before.

regards
dougal

 

What's the question? If you are wondering which would be more sensitive and less prone to false triggering, I suggest the Maplin device. It has a 12F629, which probably provides a carrier modulation of the IR and two channels of signal modulation.

The latter device is just a 5KHz carrier. Modern detector modules will turn down gain when confronted with a simple carrier like that. You will also have more interference for other sources of IR.

John

 

thanks john
i will go with the maplin,
the second circuit which i shall probably check out for future projects , would be similar to a tone control radio RX of old, will no doubt have a limited range , and as you say may be prone to false triggering from other remotes,i was thinking of 10 khz for the second channel?
thanks again
dougal