Forums » General Electronics Discussion

Hey guys, I'm a new poster.

I've joined because I'm looking at expanding my knowledge of all things electronics.

My first project I've started on is building a Variable DC Power Supply for a friend who is a tattooist.

I'm hoping I can recieve some pointers from anyone willing to help.

• The input for my power supply is going to be just a standard 12VDC Power Supply
• The output voltage needs to range from somewhere between 5-10VDC (with a little leeway)
• Current will be no more than 1.5A
• ON/OFF Isolator
• LED Indicator
• Standard female jack for the input (common size)
• 1/4" (guitar jack) for the output

The components I have bought and believe I need are (including extras): - 1x LM317T - 2x 270Ohm Resistor - 1x 10K POT - 1x 5K POT - 2x 1/4" Jack - 1x DC Power Supply Jack - 1x Isolator - 1x 12v LED - 1x 0.1 Micro Farad Cap - 1x 1 Micro Farad Cap - Steel Enclosure (To use as heatsink) - 2x Small PCB

Here's a circuit I drew up for my project I'm just sort of lost as to where I need to connect a couple of things. Hopefully someone can help

@jjdans,

Welcome to CL.

Have a look at this:

and the following thread from here down:

https://www.circuitlab.com/forums/support/topic/ffgw6682/lm317-does-not-regulate/#comment_2631

and have a search of CL for LM317.

Also search TI.com for datasheets and apps notes for the LM317.

This may also be of some general help:

https://www.circuitlab.com/forums/basic-electronics/topic/9dg62j8d/help-for-beginners-hobbyists/

Thanks @signality I had a look at a couple of LM317 circuits online

Do you think this one could work?

Thanks!

Well done. That's pretty much right.

Here are a few suggestions and bits you may not have picked up from the datasheets etc:

:)

You may also want to consider a series diode for input polarity protection and maybe a fuse.

Then you'll need to increase the input voltage to make up for the diode drop ...