This circuit is from a 1968 documentation using one of the first integrated circuits available at the time, the TAA370. The circuit is powered by 1.3 V using a 200 ohm handset.
The circuit shown in the figure consists of a fixed buck regulator using the MIC23021 integrated circuit...
This circuit can generate signals from 100 kHz to 1 MHz depending on the L1 coil. For the medium...
The configuration below, which can be implemented with other operators, is from the National...