This circuit was found in a 90s Integrated Circuits Data Book. It interfaces a data line with a CMOS input, being powered by 5V. Can be used as a shield.
This circuit can be used to recognize a tone by its frequency. When this tone is present in a...
Found in a 1980s documentation, this amplifier uses an operational aplifier of the time with two...
This circuit, from a publication of the 1970s, can compare the intensity of two light sources,...