Regulation of multiple-output DC-DC converters Patent #: 4419723
ApplicationNo. 06/481832 filed on 04/04/1983
US Classes:235/380, Credit or identification card systems235/487, RECORDS363/82With inductive control means in the line circuit
ExaminersPrimary: Pitts, Harold I.
Attorney, Agent or Firm
International ClassesG06K 7/08 (20060101)
G06K 19/07 (20060101)
G06K 7/00 (20060101)
AbstractA circuit for maximizing power transfer from a station to an interactive memory card via a capacitive interface. A reader system in the station generates an ac signal which provides operating power that is transferred to the card through the capacitive interface formed when the card is placed against a window on the station. The ac signal from the station is directed through a series resonant circuit to the card. The capacitive interface between the station and card make up the capacitive element of the resonance circuit while the series combination of the secondary of a transformer and an electrically variable inductor form the inductive element. Use of the variable inductor allows the station to tune the circuit to resonance and cancel the capacitive element, thereby maintaining maximum power transfer to the card.
Field of SearchWith inductive control means in the line circuit