View Single Post
Old 21st Jun 2018, 9:35 am   #2
Refugee's Avatar
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 3,782
Default Re: Switched Mode Power Supplies

I would go for an input of 24 volts as there are more older chips about in thru hole format.
Mains ones have a ready wound primary and are an advantage once you pick up a bit of experience.
Your best early experiment would be an auto-transformer and a UA3842 running from 24 volts. The chip needs 15 volts to start up. I use only the start up sequence to drive an electric fence so that it always pulses every second or so.
If you want to go SMD there are loads of lower voltage parts on old computer motherboards if you are prepared to trawl through the look-up tables for the part numbers.
The manufacturers data sheets are your friends here.
Refugee is offline