Powering your Arduino Unowithout a USB cable can be done very effectively with a common wall mount power supply. You just need to know the required and recommended specifications. First you would need the barrel jack measurements from your Arduino Uno which are 2.1mm ID and 5.5mm OD center positive.
For voltage requirements your Arduino Uno can run off a supply from 6-20 VDC, however the recommended voltage is 7-12 VDC as with less than 7 volts you may not have 5 volts on your 5 volt pin and with more than12 volts you may experience excess heat from your regulator.
You individual circuit will determine the current requirements for your Arduino Uno, however having a 1-1.5A supply will ensure that you are able to use the UNO to capacity.
Digi-Key’s full selection of AC/DC Desktop, Wall adapters can be found here
You can further narrow down the options by selecting your desired input voltage 6-20VDC (you will be selecting multiple option to meet this range), the out put connector (2.1mm ID, and 5.5mm OD again multiple options) and be sure to select the option for a polarization of center positive.
Other options you may want to use to narrow is the region utilized. (I for example used North America) I also selected a current of 500mA to 1.5A and narrowed options to 7.5V-12V (recommended) to see available options in stock.
Here is a link to the options I found that would meet the requirements to run the Arduino Uno Board.
1738-1228-ND 1738-1015-ND 1738-1017-ND 1738-1018-ND 1738-1019-ND 1050-1137-ND 1050-1018-ND 1050-1054-ND 1050-1008-ND 1050-1044-ND 1050-1046-ND 1050-1129-ND 1050-1062-ND 768-1265-ND 768-1267-ND 768-1266-ND 1050-1123-ND 1050-1040-ND 1050-1001-ND 1050-1041-ND 1050-1125-ND 1050-1024-ND 1050-1066-ND 1050-1049-ND 1050-1007-ND 1050-1025-ND 1050-1065-ND 1050-1119-ND 1050-1121-ND 1050-1124-ND 1050-1057-ND 1050-1127-ND 1890-1031-ND 1660-1004-ND 1660-1001-ND 1660-1003-ND 1660-1002-ND 1050-1117-ND 1050-1017-ND 1050-1045-ND 1050-1042-ND 1050-1043-ND 1050-1047-ND 1050-1061-ND 1050-1051-ND 1660-1000-ND 1659-1004-ND A000102-ND
DFR0216 DFR0267 DFR0296 DFR0306 DFR0323 ABX00012 A000067 A000111 A000023 A000088 A000087 A000126 A000095 NERO-SP1 NERO-NP1 NERO-LP1 A000093 A000057 A000005 A000073 A000103 A000066 A000053 A000062 A000022 A000069 A000008 A000003 A000052 A000099 A000108 A000116 10021 GBX00053 GBX00067 GBX00005 GBX00003 D000101 A000046 A000051 A000060 A000061 A000074 A000068 E00037 GBX00066 ABX00003 A000102