12v power to arduino uno? Vin or Plug?

Greetings, quick question. If im using a external 12v power supply to run LEDs, should i plug the power to the Vin or to the power jack? certainly not the 5v pin right?

Run the 12 volt to your LEDs but there have been a few people had issues with 12 volts to the Arduino

So either lower the voltage to the Arduino or use a seperate PSU with a lower voltage and just keep a common ground from the LED's to the Arduino.

Ballscrewbob:
Run the 12 volt to your LEDs but there have been a few people had issues with 12 volts to the Arduino

So either lower the voltage to the Arduino or use a seperate PSU with a lower voltage and just keep a common ground from the LED’s to the Arduino.

Ok so run my 12v battery to my LEDs and run like a 9v battery with the positive to Vin Pin and ground to the LED ground on the GND Pin on the Arduino?

Yes..

Have to ask what type of batteries as some types may bring new issues into play.

Are those LEDs independent from the Arduino? So just sharing the same 12V power supply to a) drive the LEDs separately b) power the Arduino?

Or do you want to control the LEDs via the Arduino?

If the latter you have to keep in mind that the maximum current of the Arduino pins (max. 40mA each, preferred: 20mA each) and in total 200mA for the Arduino MUST NOT be exceeded if you don't want to kill your Arduino.

That said, yes you can use the same 12V for powering the Arduino and the LEDs and you can use rather the power jack than the Vin to power the Arduino plus the LEDs. The power jack has a protection diode before the power "reaches" Vin and then the regulator onboard. That means that the diode reduces the voltage a little bit, and thus reduces the overall power loss.

But generally I would recommend to use either 9V to power everything or use a transistor array (controlled by the Arduino I/O pins) to drive the load current through the LEDs (this configuration will lower the overall power loss of the Arduino).