Device housing a battery and charging pad

A combination of a battery housing device and a charging pad, wherein:

• the battery housing device comprises an internal battery and a receiving coil that supplies charging power to the internal battery;
• the charging pad comprises a transmitting coil that magnetically couples with the receiving coil of the battery housing device and supplies charging power,
• the battery housing device further comprises a modulator circuit that modulates the impedance of the receiving coil in accordance with internal battery information,
• the charging pad further comprises a detection circuit that detects battery information via the transmitting coil by detecting receiving coil impedance changes made by the modulator circuit,
• the modulator circuit comprises a control circuit and a load circuit connected in parallel with the receiving coil, the load circuit having a switching device connected in series with an impedance modulating capacitor, the control circuit switches the load circuit switching device ON and OFF in accordance with battery information,
• the modulator circuit switches the switching device ON and OFF to transmit battery information to the charging pad,
• the charging pad further comprises:
• a case having a charging region capable of receiving the battery housing device in a removable manner;
• a moving mechanism that moves the transmitting coil to a position in close proximity to the receiving coil;
• and
• a position detection controller that determines the position of the receiving coil in the battery housing device placed on the charging region and controls the moving mechanism to move the transmitting coil close to the receiving coil in the battery housing device,
• wherein the position detection controller further comprises position detection coils disposed at a side of an inner surface of a top plate of the case, a detection signal generating circuit that supplies position detection signals to the position detection coils, a receiving circuit that receives echo signals output from the receiving coil to the position detection coils due to excitation of the receiving coil by position detection signals supplied to the position detection coils from the detection signal generating circuit, and a discrimination circuit that determines receiving coil position from the echo signals received by the receiving circuit,
• wherein the battery housing device further comprises a rectifying circuit connected to the receiving coil that converts AC induced in the receiving coil to DC to supply the internal battery with charging power, and a series capacitor connected in series with the receiving coil to input receiving coil AC to the rectifying circuit, and
• wherein, when the position detection controller issues position detection signals, the modulator circuit control circuit switches the switching device ON to connect the impedance modulating capacitor to the receiving coil.