Correct voltage regulator

Projects General Guidance
1

I´m going to install Arduino to my car and I need voltage regulator. Is this regulator working with Arduino to get lower volts?:

http://www.ebay.co.uk/itm/DC-Converter-Module-12v-20V-convert-to-9V-output-car-led-power-Voltage-Regulator-/261212233717?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3cd1765ff5

2

You are regulating in two steps, using that first regulator and the one on the Arduino. but that is probably OK and in fact reasonably safe.

There are other considerations, depending on what else you wish to connect to the Arduino.

3

use a buck module.

4

Thanks for answer. I will controll two 12vdc relay with arduino. What is buck module (I´m just a newbie with this)?

5

google to know details.