RadioShack® Infrared LED Emitter and Detector

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

I've bought two packages of these pairs. In both packages, the emitter was correctly labeled as the darker package. One package had lead length problems with the receiver. Normally the Anode lead (+ lead) is longer than the cathode lead (- lead). In this package, the flat side was the cathode as it should be but the anode side had a shorter lead. I had to look at the internals of the part from the one I already had working to figure out which lead was the correct one. In the end, I ended up disregarding the lead length and went with the flat side of the package for the cathode (I guess in this case, the emitter of the phototransistor).

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

The components were as labeled on the package for me - dark is the emitter, clear the detector.

Thanks to Matt for the hint about using a cell phone camera to see the ir light from the emitter, this was like magic!

Re. cathode & anode - the longer terminal is the anode on mine. Relevant data for the components is printed on the back of the package, so perhaps the problems some people noted above have been fixed.

Oh, and the signal from the emitter seems to come out more strongly from the top of the diode.

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

Easy to implement using the information on the package. I used it to detect a toy car's position as it moved up and down a 7 foot ramp.

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

At the time of this writing (6-28-12) the package description is correct. The EMITTER is the DARK one and the DETECTOR is CLEAR. Unfortunately, I blindly went by what others had said and blew up my detector. Here's how you can determine which is which easily: First, get a 3.9k resistor and connect the dark one (emitter) to 5 volts. Why 3.9k? Because the detector has a 1 mA current rating, which is the lesser of the two. By doing this first, you avoid the risk of blowing up the one your testing. Now get out your phone and point your camera at the LED. It should glow purple when the power is on. That's the emitter. Alternatively, you can use the diode test function on your DMM. You should get 1.2v on the emitter one way, and open when the leads are switched. The detector will show an open both ways. (Turn off the lights first to be sure) Now hook up your emitter to a 100 ohm resistor. That should give about the maximum current for it. Connect your detector to the DMM, set it to the diode testing function, wave it in front of the emitter and observe the forward voltage on your DMM. It should go from open to about 1.8v or so. If you do accidentally blow up the detector buy a replacement "phototransistor" part no. 276-145

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

I have used several of these on various hobby projects, but just as a photointerruptor, not sending signals via IR. It works fine in that application. On every package I've used the emitter is tinted and the phototransistor is clear. The description on the bag was spot on.

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

This pair are NOT a matched pair of IR emitter and detector as one would expect. The emitter is truly and IR emitter and works ok (but is pretty weak). The 'detector' is really just a photo transisitor, which is fine for detecting visible light, but isn't as sensitive to the IR spectrum as one would expect from the packaging. If you are looking for a matched pair of IR emitter/detector, I'd recommend [@].

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

Read the rest of the reviews. I had the same problem that everyone else had. The package was labeled wrong and It didnt work the way it should. From the looks of it this has been a problem for three years now and Radioshack still hasnt done anything about it obviously. Very poor documentation and a lack of response to the costomer. Very dissapointed in Radioshack.

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

I wasted an hour trying to adjust resistor values researching possible failure causes. Turns out the package says the emmitter is tinted and it is NOT. One drawing on the package says the emmitter collector is the short side with flat and the other image is the opposite. Disapointed with the Shack..

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

It doesn't appear to have a very long range, and the IR LED becomes very hot to touch even from a couple seconds of running (3V with around 1.5k ohms worth of resistors). The Phototransistor works but I'm afraid of keeping the IR LED on for very long, it may need a heatsink. You may want to go with the separate items.

Comments about RadioShack Matched Infrared Emitter and Phototransistor Detector:

Worked fine in the circuit I was building, which used 3 pairs of these as a trip beam. Adjusting the emitter output by varying a resistor made it easy to adjust for different distances and light conditions. That allowed me to adjust the output from the detector. I had to guess at a data sheet by comparing the specs on the pkg to some I found on Digikey. No problems.