This circuit is an improvement over the previous one, using the same capacitor system as a sensor. We also found it in Radio Electronics from the 80s.
This temperature compensated circuit was found in a Popular Electronics of the 1990s. The circuit...
This circuit generates sequence of pulses in order and times determined by the capacitors in pins...
This 1970s RCA circuit can be triggered by light or dark, depending on how the LDR is connected....