• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Resource icon

A variable dc power supply for electronics hobbyists 2010-07-13


rajbex submitted a new article:

A Variable DC Power Supply for Electronics Hobbyists - A variable DC power supply is one of the most important tools for an electronics hobbyist. Most of

A variable DC power supply is one of the most important tools for an electronics hobbyist. Most of the microcontroller based projects can be done with a fixed +5V supply but while testing various analog circuits you may require a varying voltage source. I have made one for myself using LM350 IC. The LM350 is an adjustable 3-terminal positive voltage regulator that can supply in excess of 3A over a 1.2V to 33V output range. They are exceptionally easy to use and require only 2 external resistors...
Read more about this article...

Bug 3y3'z

New Member
so question, what is the input voltage for this? i can see the output and whatnot being within workable means, but how do i know what kind of power and how many amperes, ohms, and volts (and all the other stuff) are required to power it up and make it work. other than not knowing that, good job.


New Member
Greetings: Q? Add variable current (within limits of the LM350)..another LM350? Advise also to those using in and around RF...make sure you use decoupling caps or you will take out IC. -Bat


New Member

u wann to +5V thn use IC 7805

Basic 220V to transformer to Brigde rectifier to Smoothing to regulated


I didn't understand quite what you are looking for? This project provides a variable DC voltage ranging from 1.25 V to approx. 18 V that is required for doing basic electronics experiments. If you are looking for a variable DC source from 220 V to 5 V, it is way out of the scope of this project.

Imran Bhatti

New Member
Variab DC Power Source fron 5V ~220 V

A simple solution to ur query is to have a Variac (i.e. an wide range auto transformer with toroidal core) & get the AC out put converted to DC by using a bridge Rectifier however sharpness & linearity of out put response may be a question mark for such a large span of out put voltage range.


New Member
hi buddy. I would like to create a voltage regulator with 1.9v < Vout < 60v using lm317hv. Too bad that part isn't available in electronic store here, can anyone give a schematic without any IC or how to expanda the LM317HV,

Latest threads

EE World Online Articles