This circuit was found in a 1980s documentation. The diodes may be general purpose diodes such as 1N34 or 1N60 and the indicator may be the lowest current range of a multimeter.
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,...