arduino mega 2560 r3 power

Other Hardware General Electronics
1

Sorry if this has all ready been posted but i cant find any thing on the subject, so im doing a diy aquarium controller, and im thinking of ways of powering the arduino one way i would like to do this is to power from a PC psu using the 5 volt (red wire) and connecting it to the USB port of the arduino

eg using a usb cable and cutting the cable and connecting the 5v and black to the usb cable

ill be using the 12v for some leds which will be controlled via pwm via the arduino
thanks for any information

2

It should be ok but check if your PSU can work with light loads :wink: but it's a big power supply only for this application.
you can't find an old 1A 12V switching adapter ?

3

its not just leds just an example it will be for relays pumps heater control and other devices so would like a bit of power

4

Many PC power supplies have a minimum load requirement for them to be regulate properly. Your Arduino may not be heavy enough for the 5V supply.

Make sure you measure the voltages while in operation to see that they're reasonable.