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.
MCP19124/5 Contains Independent Voltage and Current Control Loops Plus a Full Suite of...
This circuit was found in a 1980s documentation. The operational amplifier is of a common type at the...
This simulated circuit uses a 741 (Operational Amplifier), but other operational amplifiers can be...