This is one of the many possible siren configurations for the 555 integrated circuit. We found it in the October 1992 Radio Electronics magazine. It has a power stage.
We found this circuit in documentation from the 1950s. The circuit basically applies to germanium...
The circuit shown, with the printed circuit board, was found in an article in the June 1990 issue...
We found this circuit in documentation from Ferranti from 1968. The circuit uses transistors from that...