Powering Arduino with 12V AC-DC Adapter Jack

Question

I have 12V,700mA AC-DC adapter power jack. Is it ok power on arduino board directly using this power jack?

Though Arduino webpage suggests that arduino can stand and upto 20V power supply, I ask this because somewhere it is written that supply 12v, 700mA will end up the board to smoke and need a converter to make it 5V.

Is this correct?

Thanks, Jyoti Raj

Answer 1

You can use that to power the Arduino through the barrel jack or the VIN pin. The only way you end up with smoke is if you try to pull too much current through that setup. Don't power any motors or solenoids directly off of output pins for example.

• Jyoti Raj Sharma: I am using barrel Jack. My setup is simple it just has temperature, moisture sensors and ZigBee attached.
• Delta_G: I don't know how much power the ZigBee draws, but if it is very much then you might consider powering it separately. When you supply 12V to the barrel jack then there's a lot of power that has to be dissipated across the regulator as heat. Since there's not a very big heat sink on the regulator on the Arduino this can cause it to get hot and shut down. If you're just running the processor off the on-board regulator and nothing else is pulling power through it then you're fine at 12V.

Answer 2

Is it ok power on arduino board directly using this power jack?

it depends on the regulator used and the current you expect to draw from the regulator.

essentially, you want to make sure that the power dissipation over the regulator isn't too much. that power dissipation is proportional to the voltage drop over the regulator (Vin - Vcc) and the current draw (20ma + whatever you may draw from the arduino).

once you have that, check against the regulator datasheet to make sure that its temperature rise is within range.