How many Volts and Amperes can arduino handle?


I'm totally new to electronics and adruino's. Please forgive me for stupid questions. I have an idea how to make dawn simulator with LEDs. I plan to use a lot of them, 300-500 from first draft. LED will be in white, yellow and red color, 5mm. I thought to use 12V, ???A adapter (maybe form 12V halogen lights). LED will be connected in serial and parallel combination.

So, my stupid questions are:
Can arduino work with 12V?
How many V's A's can arduino handle?

I need those answers for start… If you can help, please do :)
Thank you!

sort by: active | newest | oldest
MatH21 year ago

"It is a common misconception that the Arduino 5V regulator will ensure that the 5V voltage remains at 5V, no matter what. IT WILL NOT! The only thing the 5V regulator can do is control current coming from the USB port or the external DC power jack. If the current is coming from an external power source directly connected to the 5V connector pin, the regulator can do nothing about it."


How would i make an on and off switch to power on and off the arduino ??? and better yet can the battery imput handle the same amount of miliamps as the usb??

Lycaon2 years ago

There are half a dozen Arduino models where the voltage regulator can supply either 3.3v or 5v and 500-500 mAh. 500 LEDs, assuming a forward voltage of 3.2v, 20 mAh per LED, a 12v power supply, and wired in a 2x by 250x series/parallel combo, is going to require a 12v 5A power supply and an additional 250 330ohm resistors. But anyway, if by "handle" you mean "supply" then my frist sentennce answers your question.

If you want an exact answer, give us an exact question.

The recommended input voltage for the Ardiuno is 7-15 V and each output can supply 40mA per pin. The full specifications for the Arduino can be found on the Arduino website:http://arduino.cc/en/Main/ArduinoBoardUno.  This is not nearly enough to drive a few hundred LEDs.  You could use a 12V supply to power the Arduino for the logic part of the circuit, but the LEDs will need to be driven with a dedicated driver circuit separate from the Arduino.  You can see an example of this type of circuit in step 7 of this Instructable: https://www.instructables.com/id/Just-in-time-for-the-holidays-Hack-yourself-a-me/step7/Step-7-The-Transistor-Driver/.
davor07 (author)  advancedMischief5 years ago
Thank you very much for info!
I'll check it out
aklay__ davor072 years ago

Ermmmmm, no. This doesn't answer my queries. If I'm not mistaken the question above is how many volts and amperes can arduino handle??Jajaja, get back to me ASAP if possible.

What is your question?

Ermm, No, an Arduino can supply 40mA from ONE pin, not from all of them at once - you will rapidly exceed the total package dissipation figure if you try more.

You can not pull more than a TOTAL of 200mA from all sources, and you shouldn't exceed 100mA on any port.

Sorry, I was going off the spec on the Arduino website and didn't actually pull up the datasheet for the particular microcontroller. That's good to know.

(I didn't dig further in this case because it was obvious that a driver circuit was necessary. I do wish that specs like this were more accessible.)
LEarning to interpret the actual manufacturer's datasheet is a diffcult skill: They will always try and give you an attention grabbing data point - you have to work out what that actually means.....