These 6 to 12 V source with current up to 100 mA was found in Radio Electronics magazine from June 19666. The source has a current indicator and uses transistors of the time.
If you have old tube or transistor amplifiers that hum (60 Hz noise) the circuit shown may be the...
The integrated circuit used in this regulator is unusual, as are the transistors. The circuit is...
Other settings like this can be found on this website. This makes use of old operational...