The maximum frequency of this circuit is 500 kHz. We found it in a documentation for radio amateurs from the 1980s. The integrated circuit used is uncommon today.
This circuit is a driver for R-2R network of AD converters. We found it in manufacturer...
This circuit was found in an American publication from the 60's. The transistor is made of...
This circuit produces an audio tone on the speaker or magnetic capsule. Rx must be such that added...