Definition: US Wall Plug (Power Adapter)
The wall plug is a power adapter which converts alternating current (AC) to direct current (DC) which can be used by the Nano Board microcontroller and ESP8266 NodeMCU boards. The voltage format used by national power grids varies across the globe, so this wall plug is specifically formatted to work within the United States and across North America. It converts the ~120 Volt AC power that you find in wall outlets to 5 Volt DC power that is safe to the end user and that each Tech-Box.io circuit can use to function.