This circuit was suggested by Texas Instruments in a 1968 publication. The transistors are of the time, and modern equivalents can be used.
This circuit is suggested by National Semiconductor and has an excellent gain, for a photodiode as a...
With the circuit shown, when the brightness of one lamp decreases, that of the other increases. There is...
We found this circuit in an Intersil documentation. Temperature sensors are special components of the time,...