Newbie help. 12v regulator

Hello all, Nathan here. I'm new to this board.
I am really new to electronics, and have run into an embarrassingly simple problem.

I have a battery that can fluctuate from DC 12v to 17v providing up to 8 amps.
I have a load that needs 12v, up to 2.5 amps.

I realize how simple this must seem to the majority of you reading this. I have been working on this for some time, but knowing so little about the subject has made this problem a fiasco.

I have several 7812 Voltage Regulators from Radio Shack. The problem there is that they only allow up to 1 amp. I considered putting 3 of them in series, my thinking is that this would allow up to 3 amps, but keep the voltage at something close to 12. I don't know why I think this, but it makes sense

I also went out to a local store and bought a NTE970, but this component has proven too complicated for me to understand the finer points of setting the variable voltage to something I can use.

I would like a simple solution, if anyone knows what part I can use to provide 12vdc, with up to 2.5 amps. PLEASE let me know.


Thanks for your time.

-Nathan

you can use switching regulator such as lm2576
**broken link removed**
**broken link removed**

nugab said:

I have a battery that can fluctuate from DC 12v to 17v providing up to 8 amps.
I have a load that needs 12v, up to 2.5 amps.

Click to expand...

Note that a regulator needs a higher voltage in the input to output the required voltage, for example a 7812 needs at least 14v (Vin-Vout=2v) in the input or LM2576 about 13.5v (Vin-Vout=1.5v), if your battery voltage drops below that you will not get 12v in the output.

Alex

alexan_e said:

Note that a regulator needs a higher voltage in the input to output the required voltage, for example a 7812 needs at least 14v (Vin-Vout=2v) in the input or LM2576 about 13.5v (Vin-Vout=1.5v), if your battery voltage drops below that you will not get 12v in the output.

Alex

Click to expand...

In the case you may need to use Sepic converter topology. It will first scaled down the voltage to lower level say 10V by buck converter then again scaled up to 12V by boost conveter.

Also you can find buck boost regulator see this :
https://www.google.com/url?sa=t&sou...8OO9YqNGLWnA3FwuQ&sig2=x7u4zV2nPK0eQlY5gAqWBg
for example : input :4 - 36 v output : 12v

With considering your first voltage source NTE970 is a good idea, It is not really complicated to use .

Try this link..
Switching Regulator - Linear Technology
fill your needs, choose a component and than get the Demo Borad Design files.