In Figure 1, the 5V linear regulator (U1) delivers as much as 150mA of load current when operating by itself. Operating with the external pass transistor shown (Q1), the circuit maintains 5V ...
[Kevin Darrah] wanted to make a simple 3.3V regulator without using an integrated circuit. He wound up using two common NPN transistors and 4 1K resistors. The circuit isn’t going to beat out a cheap ...