12 --> 6v

[B&R Innovation2 10+ year member]

Hey guys a pretty simple questions but something I simply dont understand.

I want to create a circut that takes the 12v output of the car batter and run it down to 6v to power an accessory. I know there are ones I can buy for say $15 to do it...but I'd rather just bulid a circut. What do I need to do to keep it regulated as well...since obviously a cars electrical system has dips and what not? And most importanly how do I get it to drop...

I have an idea

Use a series of inductors to run the voltage down to 6v then use a 6v (whatever amp rating i need) capasitator to regulate the signal at 6v and even out the peaks and valleys.

Any input would be appreciated

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[maylar 10+ year member]

The thing you're looking for is a voltage regulator. It's an IC that comes in a 3-lead package that looks just like a power transistor. 6 V is kinda an oddball value (5 V is very common), but there are adjustable ones that can give you any voltage. Radio shack has the LM317 adjustable regulator. It uses 2 resistors to set the output voltage. You should also put capacitors on the input and output to keep the thing from oscillating (anything from 10 to 100 uF will be OK).

The LM317T is good up to 1.5 amps of output current. Above that and it gets complicated...

The data sheet for the part is here:

http://www.national.com/ds/LM/LM117.pdf

And Ratshack's page:

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F017%5F000&product%5Fid=276%2D1778