I am working on led light controlled by Arduino (Arduino Nano V3.0 or Arduino Mega2560 Rev3 I have those two I am not sure which one I will finally use).
For led light power supply I will use AC/DC converter with output 12V 60W/5A.
I would like to use same power supply to run Arduino on.
Is it possible to use it? are there any limitations when I use it (to avoid risk of damage)? Is it suitable for both variant?
(What A? is max for 12V input)
I found controversial information about this topic. Someone says 12V 1A max, someone says A is not important.
I will very appreciate to be sure how it is.
Thanks in advance
I would use a Step Down Switch Mode converter to take 12V down to 5V.
12V is OK as long as you don't power "other stuff" through the Arduino's on-board 5V regulator.
The current rating on a power supply is the maximum allowed from the power supply and the actual current depends on the resistance* of the load (). If you draw excess current you'll burn-up the power supply or it will shut-down etc.
It's like the power in your house... Here in the U.S., 120VAC is always present at a power outlet but current doesn't flow until we plug something in and turn it on. If you plug-in two hair driers at once you get excess current a you blow a circuit breaker.
- We don't usually know the actual resistance of the load and the resistance goes down if you turn-on an LED or motor, etc. The important thing is, it's a characteristic of the load that determines current.
Take care when applying 12V through the "power jack" or Vin. Powering through Vin or the power jack means that the Arduino and all peripherals that are on the 5V rail are powered by the onboard 5V regulator. The on board 5V regulator is not heat sinked so will supply limited current before it overheats and shuts down. The recommend max power dissipation for the regulator is 1 Watt. With 12V into the regulator the max current is about 140 mA (1W / (12V - 5V)). The Arduino uses around 50ma of that leaving less than 90mA (max) for everything else. I would use a buck converter to drop the 12V to 5V and connect that to the 5V on the Arduino, bypassing the, weak, 5V regulator. Then the rated current of the DC DC converter is available on the 5V line.
you can get a 12 volt to USB charger in any car parts store for chump change. just put a 12 v power point on that charger, plug in the USB converter and carry on.
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