A very very difficult question -power supply topology

[leonken]

The specifications:

 

[extraord]

is there specified AC freq ?

 

[alphi]

Input AC frequency is very important!
Pls tell me frequency,then we will give it solution.

 

[leonken]

sorry, I forget the frequency .The typical frequency is about 100Hz.
The range of frequency is from several tens to several hundrads Hz.

 

[rozerf]

A rectifier bridge circuit followed by a switch-pump voltage regulator (like MAX660) might be an way for it.

Switch-pump voltage regulators only require capacitors. Since no inductor allowed, the capacitance could be large, as well as capacitor's size.

In case, if you need an very accurate DC output, a low voltage dropout linear regulator might be required.

 

[imported_Moderator]

for one miiliwatt use a zener with a 2.2 volt rating after the bridge