I have a bicycle trainer which wasn't working and I have found out that the infrared receiver is broken.
I don't have it's schema and I don't know what I need.
I am attaching a set of pictures maybe someone can help me.
If measured when plugged in I see that the sender has 1.08V and the receiver has 3.18V. This is when I don't pedal. (I can't measure it while pedaling)

 

Looks like a Slotted Opto with just an IR transmitter and Receiver led, using the GL480 type leds

 

We use something like that at work. It's actually a complete IR receiver available in 32KHZ and 38KHZ carrier frequency.