12V adapter to 5V arduino

I need to supply an arduino mini from a 12V adapter. I am not sure how to do this but I have found this converter and I wanted to ask you if it would do the job: Waterproof DC/DC Converter 12V Step down to 5V 3A 15W Power Supply Module | eBay
I do not know if that converter would provide to much power and would be inefficient or burn the board.
Also from the same adapter I need to supply a LED strip of 12V.
Thanks in advance.

Why? Arduino can run on 12V.
Can't control 12V on the output. For that you need a buffer - simple NPN transistor between LED strip - and Gnd.
Or N-channel MOSFET.
Or transistor array chip (ULN2803A)
Or open-drain shift register (TCIP6B595)

CrossRoads:
Why? Arduino can run on 12V.
Can't control 12V on the output. For that you need a buffer - simple NPN transistor between LED strip - and Gnd.
Or N-channel MOSFET.
Or transistor array chip (ULN2803A)
Or open-drain shift register (TCIP6B595)

I have read that arduino can work at 12V but it is dangerous and I need it to work for a long time.
So I need a way to frop the voltage to 5V without wasting energy.

You don't need any kind of adapter. Arduino has an inbuilt 5V DC regulator. you may add a 200mA fuse in series with the arduino power socket. It will prevent the arduino board from getting burnt out if any short circuit occurs.

unless you are powering something from the 5V-output of the Arduino, you will not destroy or harm anything, also, the power wasted will be smaller than the power wasted in the DC/DC converter under small load.

If you need the Arduino to drive MosFET's or Transistors and only that, no need to worry.

// Per.

You can run Arduino from 5V directly, with a 5V wallwart.
Examples:
http://www.dipmicro.com/store/DCA-0510
http://www.dipmicro.com/store/DCA-0520
Connect to the power header 5V and Gnd lines.
Add a diode from 5V (anode) to Vin (cathode) to avoid reverse driving the regulator.

You can search ebay for UBEC to find a lot of inexpensive voltage converters. One supposedly can power the arduino from 12v thru the external power barrel connector. If you try to, have a multimeter connected to the arduino 5v pin to verify that the onboard voltage regulator is operating properly and maintain the arduino voltage at 5v.

An Arduino can run perfectly well from 12V applied via the barrel jack, provided you are not drawing much current from the +5V pin or from the Arduino output pins. You will know if you are drawing too much current, because the voltage regulator chip on the Arduino will get too hot to touch.

Thanks folks, very useful responses :grin: