Power supply connects with electrical load
Packaging
Power supplies are packaged in different ways and classified accordingly. A bench power supply is a stand-alone desktop unit used in applications such as circuit test and development. Open frame power supplies have only a partial mechanical enclosure, sometimes consisting of only a mounting base; these are typically built into machinery or other equipment. Rack mount power supplies are designed to be secured into standard electronic equipment racks. An integrated power supply is one that shares a common printed circuit board with its load. An external power supply, AC adapter or power brick, is a power supply located in the load's AC power cord that plugs into a wall outlet; a wall wart is an external supply integrated with the outlet plug itself. These are popular in consumer electronics because of their safety; the hazardous 120 or 240 volt main current is transformed down to a safer voltage before it enters the appliance body.