I have located the 5V voltage regulator chip on my Arduino board which I am hoping to use to power an attached device (which draws up to 500 mA at 5V). The chip is next to the plug for the external voltage supply. It says:
ON RUX 117-5. It looks like it's in a SOT−223 package (body about 6.1 by 3.4mm).
I used this page to shows 3 different possible voltage regulators from ON Semiconductors: https://www.mouser.co.uk/ON-Semiconductor/Semiconductors/Power-Management-ICs/Voltage-Regulators-Voltage-Controllers/LDO-Voltage-Regulators/_/N-5cgac?P=1z0wa29Z1z0xwtvZ1z0zlrjZ1ywvc7yZ1yxz1yoZ1ywvc5z
This gives two unique data sheets for NCP1117LP and NCP1117, NCV1117. But this is where I'm stuck. They look pretty similar but not exactly the same data sheets. Also I don't know what RUX stands for, perhaps this is important in figuring out what power rating the Arduino 5V line has. Additionally the mouser.co.uk site says they're in SOT-223-3 packages but then gives dimensions which a) aren't the dimensions of the chip I have and b) are the dimensions of the SOT-223-4 package (6.3mm wide instead of the ~6.1 mm I have).
I don't care about the dimensions but I would like to correctly identify the chip on the Arduino board to be able to know what power I can draw from it before it shuts itself down.