This power supply was found in a RCA publication from the 1970s. The circuit uses transistors from that time. Modern equivalent transistors can be used.
This circuit was found in an Electronic Design from the 90s. Operational amplifiers admit modern...
The presented circuit is based on an operational transconductance amplifier (OTA) having been...
Found in an 80's documentation this circuit uses an integrated from the uncommon era today. Other...