Different standards belong to different alliances or companies. These four standards belong to Wireless Power Alliance (WPC) and Duracell Powermat Company (a joint venture between P&G and wireless charging technology company Powermat).
A4WP is the abbreviation of Wireless Power Standard Alliance, which was established by Qualcomm, Samsung and Wireless Power Alliance. The alliance also includes members such as Ever Win Industries, Gill Industries, Peiker Acustic and SK Telecom. The goal is to establish technical standards and industry dialogue mechanisms for wireless charging equipment for electronic products, including portable electronic products and electric vehicles.
In addition, Powermat is one of the supporting members of the Wireless Power Alliance (A4WP) standard. There is already an at&; T, Google and Starbucks all joined the PMA alliance. PMA Alliance is committed to creating wireless power supply standards for mobile phones and electronic devices that meet IEEE Association standards, and is in a leading position in the field of wireless charging.
INPOFi ("invisible electric field", that is, "invisible energy field") wireless charging is a new wireless charging technology. Its wireless charging series products adopt intelligent electric transmission wireless charging technology, which has the characteristics of no radiation, high electric energy conversion efficiency and weak thermal effect.
Details can be found online.