Found in an EDN from the 1980s, this circuit uses a double 555. The circuit activates a relay that controls a horn or siren. Next to the diagram we have the timings.
This circuit was found in a 1981 documentation. The circuit produces intermittent beeps serving two...
This setting appears elsewhere in this site from other sources or projects. Instead of the lamp...
This circuit was obtained in a 1964 Electronic Design. Equivalent modern transistors can be used....