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.
This circuit only detects variations in light falling on the sensor. The circuit uses an LM380 as a...
This is the well-known lightning lamp that was published in the March 1988 issue of Saber...
This photoelectric cell light relay was found in Radio Electronics magazine from April 1958. The...