This circuit was found in the February 1985 issue of Radio Electronics magazine. It is based on an AY-3-1350 melody generator that was common at the time. It is suitable for analog lines only.
Delayed Pulse Generator This can be considered an "advanced" application where two 555 integrated...
We found this circuit in a 1994 publication. It makes use of a divider for 16 384 CMOS type 4060. By...
This buffered version of the previous circuit appeared in an article in the September 1989 Radio...