This circuit is from the Linear Applications Handbook of the National Semiconductor of 1994. Transistors are common, but the integrated circuit is not easy to obtain today.
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...