Hey all,
I'm trying to make a simple IR gate which produces a TTL (LVTTL would be preferable, but TTL is ok) compatible output and a medium switching speed (75us or less).
I found that the Fairchild QSE156 does just that so I got a few of them to test along with the paired emitters QEE123. Everything looked simple enough, but I cant seem to get the detector to do anything. Im running about 40mA through the emitter about 1.5 inches from the detector. The detector is hooked up to a 5V (+/-10%) source.
Now the problem is that no matter what I do, the Vout on the detector shows 4.6V. It doesn't matter if the emitter is off, blocked, or shining right on the detector from 1cm -- it's always 4.6V. I would expect (and I want) to see the Vout ranging from 0 to anywhere above 2.4V.
Any help would be appreciated. The datasheets for the parts I am using are at:
Emitter: https://www.electro-tech-online.com/custompdfs/2008/01/QE2FQEE123.pdf
Detector: https://www.electro-tech-online.com/custompdfs/2008/01/QSE159.pdf
thanks!
Jay
I'm trying to make a simple IR gate which produces a TTL (LVTTL would be preferable, but TTL is ok) compatible output and a medium switching speed (75us or less).
I found that the Fairchild QSE156 does just that so I got a few of them to test along with the paired emitters QEE123. Everything looked simple enough, but I cant seem to get the detector to do anything. Im running about 40mA through the emitter about 1.5 inches from the detector. The detector is hooked up to a 5V (+/-10%) source.
Now the problem is that no matter what I do, the Vout on the detector shows 4.6V. It doesn't matter if the emitter is off, blocked, or shining right on the detector from 1cm -- it's always 4.6V. I would expect (and I want) to see the Vout ranging from 0 to anywhere above 2.4V.
Any help would be appreciated. The datasheets for the parts I am using are at:
Emitter: https://www.electro-tech-online.com/custompdfs/2008/01/QE2FQEE123.pdf
Detector: https://www.electro-tech-online.com/custompdfs/2008/01/QSE159.pdf
thanks!
Jay