Progress rpt: Now that I see you are still with us, Chris. I bread boarded the 36 kHz pulsed IR LED transmitter. Strange results, detection with TMF5360 worked fine- even with IR LED removed, added more power de coupling to no avail; seperated Tx & Rx by 4 ft & used seperate power supplies. Still would see around small bolckages untill LED current was reduced to 13 mA. Tuning is quite broad. Current drain - just two 555 unloader oscillators; 20 % duty on 36K Hz, 10% on pulser, so about 2% at 13mA for IR LED. Have you picked out illuminating LEDs yet ?

Have you tried a Fresnel lens sheet?

Cut it down to just a bit larger than LED size, and do the same for the detector? IR LEDs and detectors are wide angle so aiming doesn't need to be precise, the cheap Fresnel magnifying sheets could be cut up and maybe help?

 

I think this is a re-activated dead post, but thanks thatoneguy, yes ,fresnel was tested, but not as good as cheap plastic lens from Anchor Optics @ about US $ .50. as used on another post for a beam break ckt.

 

I think this is a re-activated dead post, but thanks thatoneguy, yes ,fresnel was tested, but not as good as cheap plastic lens from Anchor Optics @ about US $ .50. as used on another post for a beam break ckt.

That's good to know.

Apologies for bumping the thread, didn't look at the older dates.