Can you give 12.3 Volts on Vin pin of Uno?

Hey everyone, i am making a project. In order to power the whole thing, i plan to use a 12 volt power adapter rated for 2.3 Amps. the issue is that when i checked the voltage output of the adapter using my multimeter, i found it is actually outputting 12.3 volts. will it be ok to use this adapter with the Vin pin of arduino uno? is it tolerant enough to receive 12.3 volts? any help would be greatly appreciated.
thanks in advance!

Borderline dangerous, but yes, up to 16volt (capacitor ratings) should be possible.
It's better to use the DC socket of the Uno, which also has reverse voltage protection.
Note that at this voltage you basically can't power anything else off the 5volt pin of the Arduino without overheating the 5volt regulator.

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Thanks for the reply man.
So this wouldn't be feasible as i have to power other components using the 5 volt pin as well. Any recommendations that you could give?
Also would it be possible to simply hook up a couple of resistors in series to lower the voltage a little? If yes which resistors should i use? And it would be great if you could explain if the current being drawn in any circuit has an effect on the resistors? I am a newbie and this resistor thing really confuses me.

Ps. I know these are alot of questions, but i really need some guidance so your help would be greatly appreciated

No, the voltage drop over the resistors will vary based on the instant current requirement. E.g. if a led is on, the circuit will draw more and the voltage drop will be higher than when a led is off.

Further advise depends on which Arduino you are using.

1. If feed via barrel jack, the input voltage range is: 7 V - 12 V (Fig-1).


2. If feed via Vin-pin, the Fig-2 is the situation (Fig-2):

You could use a DC-DC voltage converter, otherwise known as a "buck regulator". There are lots available on eBay etc. Choose one with significantly more current capacity than you need.

You need to study the law.

But the question is - is there anything you are using that needs 12 V. If not, then a 12 V supply is the wrong supply!

USB "phone chargers" are readily available having a regulated 5 V output and those for the iPad and similar tablet are generally rated at 2.1 Amps.

If you connect them to the USB socket on the UNO, you can draw from the "5V" pin (with all grounds connected of course) about 500 mA minus what the UNO (and everything connected to its output pins) takes.

It is better to connect your 5 V to all the devices requiring 5 V and the "5V" pin to power the UNO itself, but you must disconnect the 5 V supply from the "5V" pin whenever you need to plug the USB into your PC for programming or serial communication. :+1:

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