XINGYHENG 50 Pairs 5mm 940nm Infrared Diode LED Emission and IR Receiver

Came quickly and works well.

Not good. Most of them didnt work. Waste of money. If you’re planning on getting these for a light gun build. Don’t bother. 90% of the LEDs were wasted and the ones that did work can hardly be picked up by a light gun. I bought other LEDs off an another website. 100 times better than these ones. I have a feeling these are not 940nm. Since most of them was wasted and throw away,or I’d be sending them back.

Using these as sensors with my model railroad to determine when a train is passing a specific point. These are used to trigger electronic circuits to control actions like crossing signals and gates. The transmitter (clear) and receiver (black) work best when placed on opposite sides of the track. They can also be placed under the tracks pointing up, and angled slightly toward each other. When the train breaks the beam, the circuit turns on a small small relay that controls the signals. Can also be used to control lights on a control panel to indicate when hidden tracks are occupied. Only complaint - on the photo sensor (black) it wasn’t clear which side is cathode / anode. After experimentation, it appears to be the opposite of standard protocol for LEDs. In other words, long leg is connected to minus; short leg to +

There are errors in comments made by some customers. First, the IR receiver is not wired backward. To have a photo-diode act as a receiver it must be reversed biased. Hence why some people have commented it is wired backward, not so. Second, the receiver is not a photo-transistor, it is a photo-diode, as advertised. A transistor has three pins! Concerning the distance range between emitter and receptor, a quick test gives me ~12cm. The 45 deg. angle of reception is ~ correct. In short you get a combo of emitters and receivers for basic use at a descent price.

Only two of the "emitter" (blue) LED's have worked! I spent an age checking, Because only two working out of 50, didn't seem right! Checked with 4.5v battery assembly, Diode test on a multi-meter (wit leads) , and with HFE test on a different multi-meter.. Confirmed as only two working! All Receiver LED's seem to be ok.