The overall input to the power surface is DC (12 volts, approximately 1 amp if memory serves). The "Power Control Circuit" contains a microcontroller, one of whose digital IO pins switches the power MOSFET on or off. This on / off switching chops the DC into AC in order to drive the primary coil (the power surface). It is important that the coil be driven with AC, as this is what generates the magnetic flux that facilitates wireless communication and power.
4:49 pm
@ Anonymous,
The overall input to the power surface is DC (12 volts, approximately 1 amp if memory serves). The "Power Control Circuit" contains a microcontroller, one of whose digital IO pins switches the power MOSFET on or off. This on / off switching chops the DC into AC in order to drive the primary coil (the power surface). It is important that the coil be driven with AC, as this is what generates the magnetic flux that facilitates wireless communication and power.
Hope this helps.