Small Zener diode voltage regulator circuit with PCB, using transistor and few parts. it is simple and cheap fixed dc source circuit. As one of best choice.
Build 12V high current power supply, do not need PCB. for a 12V solar pump. It is an Unregulated 2A Power supply because load is DC motor only.
CAR Radio transmitters to use in home, need a ham radio power supply DC-12V or high current 13.8V power supply with enough power out of 5A - 30A. [...]
This is 5v 12v dual power supply circuit using 2N3055 and Zener diode for 12V then to LM309 or IC-7805 dc regulator IC for 5V output which easy circuit [...]
Simple 12V negative power supply circuit using Zener diode and transistor