Hi everyone. I have a arduino mega and a rfid reader which can be worked with 5V dc voltage and 110mA-300mA current.
Can arduino mega supply this rfid reader ?
If that's coming from the 5V pin, yes. If that's coming from an IO pin, no.
If the board is powered by USB yes, powered from 12V on the barrel jack - probably not,
powered from 7V on the barrel jack - probably yes.
When not USB powered you have to consider the power dissipation on the on-board regulator
for "5V dc voltage and 110mA-300mA current." it is probably best to have a second power supply to provide that. Make sure to hook the grounds together, as common.
The onboard regulator should have no problem supplying 300mA (+ ~80mA for the Mega).
As stated by MarkT, input voltage has to be low enough to limit the temp of the regulator.
7volt on the DC jack is a bit on the low side though. Onboard external supply detector is set for 7.3volt.
A regulated 7.5 to 9volt supply is ideal.
Leo..
Suggest you give a link to which RFID reader this is.