What are these?

I came across about 100 of these, I am not sure if they are photodiodes or LEDs would like to use them for something!  Have tried them at alot of different voltages, they all have a resistor inline with them which makes me think they are LEDs not sure on operating voltage. they also have a glass lens.

markings - mexico 1150

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My guess is that each one of these is a pair including a light emitter (LED) and light receiver (photodiode or phototransistor), and that together these are intended to be used as a proximity sensor.  That is to say, if you bring some reflective object close to this sensor, it will reflect light from the emitter into the sensor, thus giving a signal when some thing is very close to it.

The emitted light is probably in the infrared.  Human eyes can't see infrared, but your digital camera can.  Next time try looking at the (suspected) LED through the viewfinder of your camera while testing it.  And don't go crazy with the current, just a few milliamperes (mA), or else you risk burning the thing out.

Regarding the part number I found this:

That part number is for a photodiode (light sensor). 

Are both those little windowed thingies the same thingy?   I mean for my hypothesis for what this thing is to be true, one thingy has to be an emitter and the other thingy a sensor.

mutantpoptart (author)  Jack A Lopez6 years ago
I have checked them for IR on my digi cam with no results and tried them on all kinds of current, from batteries to my benchtop psu. Both of them have a 220ohm 1% resistor on them. They're a big mystery to me haha, I will see if they're the same components or different cuz proximity sensors would be great for projects! Thank you for all the help people!
I think they are photodiodes. I assume they are identical from the picture, and the fact that the OP only showed on of 'em.
acidbass6 years ago
they almost look like they have LED's embedded in them
They look like photdoiodes to me - detector of light, not emitters.