This circuit was found in RCA documentation from the 1980s. The circuit uses LDRs of the time and the 50 uA instrument has zero in the center. R1 and R2 may have 2k2 and R3 10k typically.
In the figure we show an interesting application for integrated circuit 4001. This circuit causes a...
This sensitive MW receiver was found in a publication of year 1958., The circuit uses germanium...
We found this circuit in a 1966 US documentation. It simulates a variable capacitor that can vary...