This low frequency sinusoidal oscillator was obtained in documentation from the 1970s. Operational equivalents can be used. The FET is a general-purpose type.
This limit alarm was found in a 1980s US documentation. Comparators can be equivalent and the...
Found in Popular Electronics from the 90s, this circuit powers a warning lamp when the load is...
This transmitter has excellent range when using an external antenna (respecting legal...