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.
Found in a 1990 Hobbyst Handbook this circuit has an output power of a few tens of watts and...
Two NAND gates are used in the configuration shown here to perform as a monostable triggered by...
Found in a 1980s American documentation, this circuit is based on the common CMOS series...