Theory Of Operation

The 12 volt ignition fed Wireless Charging Pad Module is an inductive charging device used to charge one cellphone unit, equipped with a special interface using an electromagnetic field to transfer energy through electromagnetic induction which supports the wireless power transfer. The Wireless Charging Pad Module has a Light Emitting Diode (LED) indicator to inform the user about charging status.

The Wireless Charging Pad Module is connected via LIN bus to the BCM. The BCM is the master node.

The Wireless Charging Pad Module operates in two basic modes: OFF (Sleep) and ON (Active). The module enters OFF mode, when it stops receiving LIN input messages from the BCM. When the BCM wakes the module with a commanded ignition state signal, the module exits OFF mode, and enters ON mode.

While in ON mode, the Wireless Charging Pad Module performs one the following functions that are defined as states:

• Idle/Searching mode 

  - This is the default state and is initially entered when in ON Mode and can be entered from any state. The module searches at a frequency of 125 kHz for devices that meet the Wireless Power Transfer (WPT) standards. To avoid interference the WCPM is turned OFF when a FOBIK search is performed. There is

  no LED indicator illumination 

  in this state. Once a device is detected, the module exits this state and enters into the Device charging state. If a foreign object is detected or if there is a module internal error, the module will enter into the Foreign Object state or the Module diagnostics state.

• Device charging 

  - While in this mode, there is a

  blue 

  LED indicator illumination while charging. Once the device is fully charged, the

  green 

  LED indicator illumination.

• Foreign Object detection 

  - When a foreign metal object is detected, the module will not radiate except to sense that the foreign object has been removed. The LED indicator

  flashes red 

  during this state.

• Module diagnostic  - This state occurs when the modules internal routine has detected a functional error. The pad will not radiate in this state and the module will communicate the error state to the BCM over the LIN bus. The LED indicator flashes red  during this state. If the error no longer exists, the module will exit this state and enter into the Idle/Searching mode.

Inputs 

• Battery critical State of Charge (SOC) message from the BCM
• The commanded ignition status from the BCM
• Door ajar switch signal from the BCM
• Dimming strategy from the BCM
• 12 volt ignition feed

Outputs 

• 15 watts at 3 amps power output
• Wireless Charging Pad Module temperature error messages to the BCM
• Wireless Charging Pad Module communication error message to the BCM
• Wireless Charging Pad Module coil disconnected error message to the BCM