A4WP Wireless Charging Includes:
A4WP wireless charging A4WP wireless signalling protocol A4WP wireless charger / PTU A4WP wireless receover / PRU
See also: Wireless charging basics Inductive power transmission Shielding / screening Qi wireless charging Buy the best wireless charger
The A4WP wireless charger or pad is known as the power transmitting unit, PTU.
This power transmitting unit is the key controller and power source for the wireless charging system.
The A4WP charger or power transmitting device contains all the electronics to enable power to be taken from the mains of other power supply and convert it into a format where it can be picked up by the receiver unit to enable it to be charged.
A4WP PTU basics
The A4WP power transmitting unit or charging pad has a number of basic building blocks within it.
The A4WP wireless charger consists of a number of blocks that provide the functionality required to meet the specification set down by the Alliance for Wireless Power.
The A4WP charger / power transmitter unit, PTU contains two main areas. One comprises the areas used for the power transfer, and the second is associated with the signalling.
The signal for the power is generated at a frequency of 6.78 MHz which is in the HF portion of the radio spectrum, in a band reserved for Industrial, Scientific, and Medical applications. Traditionally this band has been widely used for industrial inductive heating.
Also generated, is a signal in another ISM band, but at 2.4 GHz. This link is used for the data transfer for control between the A4WP power transmitting unit and the receiving unit.
Both signals are generated and amplified to the required level before being applied to the transmit resonator.