Pulse/direct current transmitting circuit in a key telephone system
Battery feed circuit for subscriber line
Active impedance line feed circuit
Switching voltage regulator for an interface circuit in a telephone subscriber line
Battery feed circuit
Power supply for telephone exchange
Terminating circuit in a battery feed circuit of an electronic exchange system Patent #: 4982422
ApplicationNo. 852538 filed on 03/17/1992
US Classes:379/412, Protective circuit379/413Power supply (e.g., battery feed)
ExaminersPrimary: Dwyer, James L.
Assistant: Smith, Creighton
Attorney, Agent or Firm
International ClassH04N 009/08
Foreign Application Priority Data1991-03-19 JP
AbstractA power and signal transmission system performs a transmission of a power from a first communication device to a second communication device via a transmission path as well as a transmission of a signal between the first and second communication devices via the transmission path. The first communication device includes a high voltage power source and a first pair of active inductances each having a low DC impedance and a high AC impedance, through which the power from the high voltage power source is supplied to the transmission path, and the second communication device includes a DC/DC converter and a second pair of active inductances each having a low DC impedance and a high AC impedance, through which the power transmitted via the transmission path is supplied.