The LM121 integrated circuit is no longer common in our market, with more modern equivalent versions. The circuit is from the 1994 Linear Applications Handbook by National Semiconductor.
This circuit applies to other operational ones, other than the one indicated. The formulas next to the...
We found this circuit in the Audio Handbook of the National Semiconductor of 1977. The circuit is used...
This photometer was found in an English magazine in 1981 but can still be mounted today with...