This circuit is based on a Siemens S566B integrated circuit. The circuit is from a Radio Electronics Experimenter and also has a digital control input.
This circuit with only one transistor was found in Japanese documentation from the 1960s. The...
This circuit uses a common multimeter on the voltage scale. The calibration of the scale should be...
This interface shield circuit is from the 1983 Intersil Databook. The components used are uncommon...