This circuit is from a 1977 Radio Shack manual. The photocell is an LDR and the operational one is a 741. Components with non-standard values can be approximated.
We found this circuit in the June 1992 issue of Radio Electronics magazine. The sensor is a common...
This circuit converts a positive CMOS supply voltage to a negative one. We found it in a 90s...
This tone control was obtained from the CA3140 datasheet, originally created by RCA. The CA3140...