We found this receiver circuit for modulated light in a 90s Popular Electronics. Equivalent audio amplifiers can be used. Transistors are commonly used.
This conventional power supply circuit with the LM317 was found in a 1987 publication and its...
July 2017 - The new TLP240 and TLP241A optical couplers with MOSFET output, manufactured by...
This is the receiver for the previous circuit found in the November 1991 Radio Electronics...