Abstract: A charging system for a mobile device includes a transmitter and a receiver. The transmitter includes (a) a first interface to a power source; (b) a second interface to the receiver; (c) a polarity detection circuit for detecting polarities of the; and (d) first and second switches controlled by the polarity detection circuit, wherein each switch selectively connects a terminal of the first interface to a terminal of the second interface. The receiver includes: (a) a first interface; (b) a second interface coupled to a device to be charged; and (c) a connection circuit between a terminal of the first interface and a terminal of the second interface, wherein the connection circuit is conductive when the voltage across these terminals is of a first polarity, and a second polarity otherwise.

Abstract: A charging system for a mobile device includes a transmitter and a receiver. The transmitter includes (a) a first interface to a power source; (b) a second interface to the receiver; (c) a polarity detection circuit for detecting polarities of the; and (d) first and second switches controlled by the polarity detection circuit, wherein each switch selectively connects a terminal of the first interface to a terminal of the second interface. The receiver includes: (a) a first interface; (b) a second interface coupled to a device to be charged; and (c) a connection circuit between a terminal of the first interface and a terminal of the second interface, wherein the connection circuit is conductive when the voltage across these terminals is of a first polarity, and a second polarity otherwise.

Abstract: A wireless direct contact charger includes (a) a voltage supply; (b) a first plate electrode and a second plate electrode; (c) a polarity detection circuit that detects; and (d) a switching circuit. When the first electrode or the second electrode of the portable device is placed on the first plate electrode or the second plate electrode, the polarity detection circuit detects the polarity of the portable device charging terminals (i.e, whether the first electrode of the portable device is in contact with the first plate electrode, the second electrode of the portable device is in contact with the first plate electrode or any other suitable orientations).