Can i use voltage regulator for VIN pin?

I have 22V battery (6S Lipo). I wanna power Arduino using VIN pin. VIN pin accepts voltage that is not above 12V. I'm wondering if could I use 9V voltage regulator to fit VIN pin input requirements. I read Arduino Nano documentation, it suggest using an unregulated voltage source.
I know that I can just simply use 5V input safety with appropriate regulator. But I'm just wondering what would be if would use a voltage regulator before VIN pin and why Arduino documentation suggests not using regulators for VIN pin.

The Nano will not know or care where the 9V is coming from, regulated or not so you can do what you describe

The only downside is that you are wasting power by dropping the voltage twice, once externally and again on the Nano. but this may not matter to you

What is says is that you can use an unregulated supply, not that you can't use a regulated one

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This is the part of the nano schematic that shows the Vin pin.

See that internally in the nano this pin is connected to an LM1117IMPx-5.0V regulator.
This regulator needs an input of at least +- 7V so that it can then supply 5V to the rest of the circuit.

image

Why do you think it is safe?

Yes. But it's also have a limitation of maximum 20V input voltage. As I'm using 22V battery, the voltage should be regulated below 20V. For this reason I'm wondering if it's possible to use one more voltage regulator. For example convert voltage to 9V using my regulator and then Arduino internal regulator will convert it to 5V

Maybe i'm wrong, i'm not expert in circuits analysis. My plan was to use 5V regulator that handle 22V input power supply (for example LM317T voltage regulator). LM317T can handle 22V input and as Arduino does not draw too much current, the voltage regulator should not be overheated.

Yes, power wasting doesn't matter for me, it was just my wondering. Thank you for your answer

Arduino advises against powering a board at the 5V pin, for 2 reasons:

1 A cheap wallwart doesn’t always provide a nice, well regulated voltage. This might interfere with your processor or even damage it.

2 Some boards use a MOSFET to switch from external power to power from USB. This also provides a path to feed back into the USB connection, and your PC may or may not be able to handle that, so it’s not only your board but also your PC that is at risk. (The Nano uses a diode instead of a MOSFET, thus providing some protection.)

So: yes it is possible to power a board from the 5V pin, but…


As for energy: if you use a linear regulator to convert from 22V to 5V or 7V, about 80% of your battery capacity will get turned into heat.

If you have a switching regulator for 7V, or a GOOD one for 5V to power your Nano, your battery life may be up to 4 times longer.

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As I'm planning to make quadcopter, my battery capacity will be drawn quickly anyway by 4 motors. I decided to use linear voltage regulator as switching regulators have susceptibility to power noise.

So, there is no way to power Arduino from battery and upload a code simultaneously?

Thank you for the really useful knowledge.

With your Nano the diode offers protection.

For boards like the UNO R3 it depends on the PC maker.

(I expect most modern PCs to be safe, but I can’t guarantee anything.)

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By the way: if both battery and USB are connected, the board will consume power from the battery.

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