As the title says I want to no how much AMP's can arduino handle on from input through the adaptor power socket Im not worried about pins all I want to know how much can go in cheers. 
Less than 1. The reverse polarity protection diode that is in series after the barrel jack is rated for 1A.
Excellent thanks very much
Im not worried about pins all I want to know how much can go in cheers.
Just so we're clear.... The current depends on the load ([u]Ohm's Law[/u]).
That means you can use a power supply capable of 10Amps or a 12V car battery capable of hundreds of amps and nothing bad will happen unless you connect something to the Arduino's 5V pin that draws too much current.
DVDdoug:
The current depends on the load ([u]Ohm's Law[/u]).
An Arduino board is not a resistor so Ohm's law does not apply.
The supply current and ground current of an ATmega328 microcontroller chip (for instance) should not exceed its maximum rating of 200mA. The current will depend on the loads placed on output pins. I doubt other things on an Arduino board draw much current.
The supply current and ground current of an ATmega328 microcontroller chip (for instance) should not exceed its maximum rating of 200mA.
That is true for a DIP component with a single VCC pin. 32-pin SMD parts with 2 VCC pins can do more as evidenced by the notes in Section 29, where the current totals are 300mA:
3. Although each I/O port can source more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed:
ATmega48A/PA/88A/PA/168A/PA/328/P:
1] The sum of all IOH, for ports C0 - C5, D0- D4, ADC7, RESET should not exceed 150mA.
2] The sum of all IOH, for ports B0 - B5, D5 - D7, ADC6, XTAL1, XTAL2 should not exceed 150mA.
If IIOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition.
4. Although each I/O port can sink more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed:
ATmega48A/PA/88A/PA/168A/PA/328/P:
1] The sum of all IOL, for ports C0 - C5, ADC7, ADC6 should not exceed 100mA.
2] The sum of all IOL, for ports B0 - B5, D5 - D7, XTAL1, XTAL2 should not exceed 100mA.
3] The sum of all IOL, for ports D0 - D4, RESET should not exceed 100mA.
If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition.[code]
CrossRoads:
That is true for a DIP component with a single VCC pin. 32-pin SMD parts with 2 VCC pins can do more as evidenced by the notes in Section 29, where the current totals are 300mA:
I think you also need to note the 'Absolute Maximum Ratings' (Section 28.1):
DC Current VCC and GND Pins................................ 200.0 mA
Yes, but that is PER PIN. Two Vcc pins = 400mA. Four Vcc pins = 800mA ('2560).
I have this documented from Atmel (and have posted it previously).
CrossRoads:
Yes, but that is PER PIN. Two Vcc pins = 400mA. Four Vcc pins = 800mA ('2560).
I have this documented from Atmel (and have posted it previously).
Thanks. That's certainly not clear from the datasheet!
Yes, the Absolute Max section could have said PER in both these lines:
"DC Current per I/O Pin ................................................ 40.0mA
DC Current VCC and GND Pins................................. 200.0mA"
This is more of a geek curiosity question than a practical one. Would 20 mA out on one pin be balanced by 20 mA in on another pin? That is, would either of those pins contribute to the load going through the VCC and GND pins or would they, at least approximately, cancel each other out?
Please don't anyone spend time researching this. It's not that important. Just if someone happens to already know.
No. 20mA comes in on Vcc pin, goes thru transistor out of pin, comes in on input pin, goes thru transistor and goes out on Gnd pin.