Hi guys,
I've got a question about the NHduino Uno.
Is it possible to supply this NHduino Uno with a voltage of 5 volt and a current of 3 amps?
I've got a question about the NHduino Uno.
I don't know anything about that version...
Is it possible to supply this NHduino Uno with a voltage of 5 volt and a current of 3 amps?
Yes. You can use a 5V, 3A power supply and the Arduino will only use a fraction of that available current.
[u]Ohm's Law[/u] says:
Higher Voltage = Higher Current
Higher Resistance (or impedance) = Lower Current
We don't know the resistance or impedance of the Arduino and it's not constant (although we can calculate the effective resistance if we measure the current), but the important thing is that the current depends on the load (and in this case, the load is the Arduino).
For example, a car battery is capable of supplying hundreds of amps to the starter, but if you connect a regular little LED with the normal current-limiting resistor you'll only get about 20mA through the LED. With nothing connected to the battery, 12V is still present but no current is flowing.
On the other hand, if you connect a 10A motor to your 3A power supply the voltage will drop and you might burn-out the power supply.
It's the same thing with the electricity in your house.... The voltage is always present but current only flows when something is plugged-in and turned-on. A 100W light bulb draws less current than a hair dryer or toaster. If you plug in too much stuff, too much current flows and the circuit breaker blows.
More amps the better. Devices only draw what they need. They don't get force fed current just because it's available.
As long as your voltage matches what is required and the amperage is at LEAST what the device will use, you're fine.
Load current is a function of source voltage and load resistance (I=V/R)
I see! Thanks for the answers.
I'll check the resistance of the arduino.
And then I will try to simulate it with the resistance of the arduino as load.
jacky1997:
I see! Thanks for the answers.
I'll check the resistance of the arduino.
And then I will try to simulate it with the resistance of the arduino as load.
I think you'll find that that won't work. The Arduino is just a wee bit more complicated than a resistor.
Just a wee bit. 
Oh come on !
An UNO draws about 50 mA @ 5 V.
5 V/0.050 A = 100 ohms.
P=I *V= 0.050 A * 5 V= 0.250 W
R= 100 ohm, 1/4 W
How complicated is that ?
Actaully, a CMOS digital chip with a constant switching frequency probably does act like a reasonable approximation to a resistive load.
You just aren't going to measure that with an ohmmeter.
That's irrelevant The OP asked for the equivalent resistance which is , for an UNO , 100 ohms.
Read Reply#1 and Reply#4.