This sensor circuit from a 1967 Ferranti documentation uses components from the era. The circuit can be used as a shield, although the integrated one used is unusual today.
This circuit was found in a 1998 documentation and its purpose is to automate controls by timing its...
This circuit is from a 1977 Radio Shack documentation. It produces a modulated sound of good...
This second-order filter was found in old American documentation and can be applied to other...