We found this circuit in a 1996 publication. The circuit uses components that are still common. The timing depends on C1, which can be changed, and the triac can be of any type.
This circuit with an integrated circuit of the time was found in the magazine Radio Electronics of April...
This circuit was found in a 90s Popular Electronics. It uses an LS3404 melody chip that has...
This circuit was found in Radio Electronics magazine from August 1966. The transistors are from...