+5V Supply using 12V Wall Wart

Thread Starter

miniengine

Joined Sep 6, 2009
7
Would a 12V 800mA wall wart suffice as a proper input to make a 5V Power Supply for Breadboard circuits needing less than 1 Amp current? Recommend a schematic please. Thank you
 

nanovate

Joined May 7, 2007
665
Yes.
The datasheets for a LM317 or LM7805 could be a starting point for a schematic. These would work without a heatsink to about 250 mA.
 

SgtWookie

Joined Jul 17, 2007
22,201
You didn't say whether the output from the wall wart was AC or DC. That makes a difference in the design.
 
Slightly off topic:

Why is it that when I run a 78M05, for a PIC and 7 segment LED, there is no heat when reducing to 5v from 12v? Is the small amount of amperage I'm drawing the reason?
 

SgtWookie

Joined Jul 17, 2007
22,201
Slightly off topic:

Why is it that when I run a 78M05, for a PIC and 7 segment LED, there is no heat when reducing to 5v from 12v? Is the small amount of amperage I'm drawing the reason?
Yes. It's best to start your own topic though; otherwise the thread can get confused very quickly.
 

SgtWookie

Joined Jul 17, 2007
22,201
You're welcome, Ray.

A note on the LM317 schematic - the terminal labeled as "COM" is actually the "ADJ" terminal.

For more information on the LM317 regulator, go to National Semiconductor's site:
http://www.national.com
and download the datasheet for the LM117/LM317.
 
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