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 originally designed with the operational 747 which is rare today. However, the...
This circuit was found in a 1975 technical publication. The circuit can be designed with 741...
The TDA2613 is the mono version of the TDA1521A and has pinouts compatible with an integrated...