12V DC Regulator

[KC2UGV]

I'm looking to build a 12VDC, 2A minimum regulator for my car.

I know, first question is: Why?

Well, two-fold:

* I'd like to keep a constant voltage of 12V (Not 13.8VDC nominal) to my handy radio, which will serve as a data radio for the car. It needs 12VDC (According to the manual), but appears to run fine on 13.8VDC(From my base station power supply). I'm trying to be safe here.

* I would like for the radio to turn off is vehicle power drops below 11VDC (Safe start voltage). This is secondary, I know I can just turn off the radio. It's for those "Oops, I forgot" times.

Anywhere I should start looking for template circuits here, and build instructions? First time in higher-power applications (couple hundred milliamps has been my experience, and that's in signaling), so it's kind of, new ground for me.

[WØTKX]

Double check the input circuit for 12 volts on that radio, it may be regulated already.

Here's a "cookbook" of sorts, IC regulators are cheap.

http://www.teachers.ash.org.au/jfull...regulators.htm

LM350 is a good choice, 3A max.

http://www.national.com/mpf/LM/LM350.html#Overview

Suggested RadioSnack semiconductor part numbers... will work up to 1.5A, just heatsink the snot out of it?
Do you really need 2A? Measure it.

http://www.radioshack.com/product/in...ductId=2062601

Using the LM317 above because the "Snack" is everywhere. They also have a 2N3055 power transistor that is a 30A overkill, but a popular combo. RS available TIP42G might work as well as some others they have.

The LM350 is a nice simple solution.

[KC2UGV]

Thanks :) Bookmarked for great justice!