This monostable circuit, from a 1977 Radio Shack documentation, uses a 7400. The time is given by the capacitor and the power must be supplied with 5 V.
This simple alarm was found in a 1982 documentation, but uses components that are still common,...
Found in a 1969’s Electronic Design, this circuit operates in a narrow range of voltages....
This experimental circuit was found in a technical publication from 1976. The diode can be of...