This simple 12 V power supply with current up to 2 A was found in a Popular Electronics from the 90s. The zener diode is 14 V and transistor Q2 can be a TIP42.
In figures 1 and 2 we have two current drains that can be made with operational amplifiers and...
Great sensitivity for the circuit can be obtained with a Darlington amplification step for the...
The used diode is an unusual component today. We found this 12 V regulator in documentation from the...