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Need IC part number 16VDC->12VDC

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  • Member since
    December 2004
  • From: Pa.
  • 3,361 posts
Need IC part number 16VDC->12VDC
Posted by DigitalGriffin on Tuesday, August 28, 2012 9:12 AM

For the bloody life of me I can't find the part.  I've looked 2 hours.

I want an inline package IC in: 16VDC to out: 12VDC.  I want to power some low power accessories from my MRC AC terminals (18VAC->Full bridge recitifer->voltage converter) 

I know they exist and are cheap, but I can't find the darn things.

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Tuesday, August 28, 2012 9:18 AM

What you need is a simple 12 Volt regulator.  All Electronics has a LM340T-12 priced at 50 cents each.  You may also be able to find these at any electronics supply house except Radio Shack.  All the local RS stores have stopped selling any components.

Circuits utilizing regulators are available on the internet, and consist of nothing more than a capacitor on the input and a capacitor on the output.

Here's a link to the National Semiconductor tech sheet for a LM340 series regulator, including circuit details.

https://www.national.com/ds/LM/LM340.pdf 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, August 28, 2012 5:08 PM

 Or an LM7812. Lower power than the 340, but still capable of an amp if a heat sink is added.

            --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Tuesday, August 28, 2012 7:14 PM

DigitalGriffin

For the bloody life of me I can't find the part.  I've looked 2 hours.

I want an inline package IC in: 16VDC to out: 12VDC.  I want to power some low power accessories from my MRC AC terminals (18VAC->Full bridge recitifer->voltage converter) 

I know they exist and are cheap, but I can't find the darn things.

 

Knowing how to ask the question can be the most difficult part of a Google search. voltage regulator 12 vdc would have been a good way to start a search. Then just download the PDF and check the specs.

I use the LM317 with two resistors and the two capacitors for different voltages, along with a heat sink.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    December 2004
  • From: Pa.
  • 3,361 posts
Posted by DigitalGriffin on Tuesday, August 28, 2012 8:37 PM

Thanks gentlemen.  Found almost instantly what I was looking for @ mouser after I got a part #

Much appreciated as always!

-Don

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
    May 2012
  • 602 posts
Posted by NP01 on Tuesday, August 28, 2012 10:34 PM

Ooh the LM340T. I think I worked on a little piece of that one when I was at National Semiconductor. Fond memories. 

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