This sequential circuit appears in other versions on this site. This is from American documentation from the 1960s. The speed of the effect is set to R1.
This 1.5 A source for FM transmitters was originally intended for the transmitter described in...
This metronome configuration with the 555, quite common was found in a 90s Hands On Electronics. The...
This circuit was found in a 1958’s publication. It uses germanium transistor, availble that time....