This circuit is designed for MCUs and low power components. You will need to tweak this according to your own peak current needs. This circuit has no idle current and therefore efficient while the system is at rest (wrong, the idle current is high, I'll fix it.). It further is capable of delivering upto about 100+mA at 5v.
The latest addition is a variable and stable voltage regulation with potentiometer.
The 20v zener protects the MOSFET gate from a higher than 20v GS voltage difference.
This circuit is dangerous, since it has no galvanic isolation to the mains power. Therefore, no wires must leave the box that you plan to put this in. It is a power supply for a specific device, and not a power box. (take care)
