Transistor Variable power supply 1A, 0-30V project with PCB. Using transistor boost current to 1A. No IC. No Zener diode. But steady voltage.
This is three Simple 50w OTL audio amplifier circuit by 2N3055, can build easy and cheap, It's durable and very loud sound , Not needed speaker Protection. [...]
This Small 5-volts DC Regulator. without IC-7805. Using transistors are interesting. If you have an old transistor or want to save. It may be a good choice.
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 [...]