Abstract: The user of a portable device defines the charging direction when two devices with bi-directional power transfers interfaces are interconnected. The device detects a gesture of the user and starts the power transfer to the defined direction. The user may also define the amount of charge to be transferred by the same gesture. The portable device may be operational for a longer period as long as there is another device sharing the battery charge. Embodiments of portable devices include smartphones, speakers, tablets, watches or other wearable devices.

Abstract: A diagnosis device and method of a voltage transformer can include a current transformer disposed at one side of an output port for generating a current variation according to an on/off operation of a power switch element; a first current detector configured to detect a forward direction current from the current transformer; a second current detector configured to detect a reverse direction current from the current transformer; a first voltage transformer configured to transform the forward direction current detected from the first current detector to a forward direction voltage; a second voltage transformer configured to transform the reverse direction current detected from the second current detector to a reverse direction voltage; and a diagnosis portion for comparing the forward direction voltage with the reverse direction voltage to determine whether or not an offset is formed.

Abstract: Rectifying elements are connected in parallel with switching elements 4-1 through 4-4 in a switching section 4 for the lower voltage side and rectifying elements are connected in parallel with switching elements 5-1 through 5-4 in a switching section 5 for the higher voltage side. An LC resonant circuit 6 is provided between the winding wire 3-2 for the high-voltage side in the transformer 3 and the switching section 5 for the higher voltage side; currents which flows on the primary side and the secondary side is changed into a sinusoidal one; and switching is executed in the vicinity of the zero crossing points of the currents.