This circuit was obtained in a documentation from the National Bureau of Standards of 1968. The circuit is of low current and the output can be changed to voltages between 2 and 30 V.
This amplifier from 100 to 150mW was found in a Japanese documentation from 1967. The circuit uses...
This circuit is from a manual of JFETs and can be implemented with the BF245 and for the bipolar...
This source of some amps for voltages up to 40 V was found in an Italian magazine Elettronica...