High quality switching 'wall wart' 'wall adapter' AC to DC 3.3V 2A wall power supply. These are switch mode power supplies which mean the output is regulated to 3.3V. They take 100-240Vac 50/60Hz input and output 3.3V 2A (2A is very incredible for its size). These will power most projects that don't require more than 2A of current. Center-negative 5.5x2.1mm barrel connector.
They are design to take up ONE position on your outlet strip or wall outlet. These will convert international voltage (100V-240Vac 50/60Hz) automatically; no transformer needed. The cable is about 4.5 ft. long. There is an LED indicator for supply OK. Great for many electronic projects!
There are 3 things to watch for when choosing wall adapter:
1) Voltage and Current (3.3V, 2A)
2) Plug size (2.1mm)
3) Center polarity (Negative center)
We did some testing on these adapters and here are some of the measurements:
INPUT: 110VAC 60HZ
OUTPUT: 3.40V@no load
* We're no longer sell 2.5mm version of these adatpers. If you need 2.5mm or 1.4mm version just purchase these adapter cables below.
2.1mmx5.5mm Female to 2.5mmx5.5mm Male Jack Adapter
2.1mmx5.5mm Female to 2.5mmx5.5mm Male Cable Adapter
2.1mmx5.5mm Female to 1.4mmx3.8mm Male Cable Adapter