UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Reverse engineering Lumenition optical switch

Uncle Bulgaria · 6th May 2020, 2:51 pm

Any luck, Richard? I've been trying to find datasheet circuits for possible IR receivers but haven't spotted the right one yet. As it only has two pins I presume it's a photodiode rather than a transistor. So the larger resistor should be a limiter for the IR LED, with the other part of that circuit being the diode. But then why is the diode attached to the +7.5V via the 250R resistor? I'm going to try to reconstruct the grounding if I can work out the amplifier output which should go to the blue terminal... It's moments like this when I realise how ropey my circuit theory logic is, and have to read up on Ohm and Kirchoff yet again!

6th May 2020, 2:51 pm	#6
Uncle Bulgaria Nonode Join Date: May 2016 Location: Cornwall, UK. Posts: 2,338	Re: Reverse engineering Lumenition optical switch Any luck, Richard? I've been trying to find datasheet circuits for possible IR receivers but haven't spotted the right one yet. As it only has two pins I presume it's a photodiode rather than a transistor. So the larger resistor should be a limiter for the IR LED, with the other part of that circuit being the diode. But then why is the diode attached to the +7.5V via the 250R resistor? I'm going to try to reconstruct the grounding if I can work out the amplifier output which should go to the blue terminal... It's moments like this when I realise how ropey my circuit theory logic is, and have to read up on Ohm and Kirchoff yet again!