This flip-flop controlled by an LDR-type photocell was found in Radio Electroinics magazine from June 1959. Note that it can be powered from the mains and directly controls a sensitive relay.
This circuit, obtained from ancient English documentation, produces a pulse every 24 hours when a 50...
This digital pulse counter offers an LED indication. Its maximum frequency is of the order of 5...
This circuit was found in an old RF documentation. The circuit cuts out the incoming sinusoidal...