Patents Assigned to Frederick Electronics Corporation
  • Patent number: 4425616
    Abstract: A microcoded processor for use in a distributed processing telex exchange to time share process each termination connected to the processor is disclosed. The processor executes selected signaling routines for each termination. The processor contains a sequence file that outputs the address of the next termination to be time share processed. This information controls the transfer of data between the processor and the termination currently being time share processed. Also included in the processor is a constant and a variable data file which contains blocks of data associated with each termination and which contains data needed to execute the selected signaling routine for each termination. A program re-entry file is provided to control the time share execution of each signaling routine since only a predetermined number of microcode instructions are executed in each time share interval.
    Type: Grant
    Filed: November 6, 1979
    Date of Patent: January 10, 1984
    Assignee: Frederick Electronic Corporation
    Inventor: Jack L. Woodell
  • Patent number: 4418318
    Abstract: A digital phase-locked loop consisting of a digital phase detector for detecting the phase differences between the output and the input frequency signals, a microprocessor programmed to perform both the functions of the loop filter and the phase shifter, and a binary rate multiplier to perform the function of voltage-to-frequency conversion is disclosed. A more precise frequency resolution is obtained by use of the binary rate multiplier and a further reduction in circuit complexity is achieved by removal of the phase shifter circuit in favor of the microprocessor programming.
    Type: Grant
    Filed: March 10, 1981
    Date of Patent: November 29, 1983
    Assignee: Frederick Electronics Corporation
    Inventors: Arnold Swagerty, William A. Mitchell
  • Patent number: 4355403
    Abstract: A teletypewriter line keyer with a switching current regulator responsive to a floating, loop current powered voltage comparator used as a loop current monitor. The line keyer, which may have positive and negative line current keying, uses a single current monitor to control positive and negative current regulators responsive to the positive and negative keying respectively. The switching regulators operate within a relatively narrow band centered around the nominal signaling current, with filtering being provided for ripple control. The circuit may also include a keying detector and open loop detector for system monitoring.
    Type: Grant
    Filed: June 1, 1979
    Date of Patent: October 19, 1982
    Assignee: Frederick Electronics Corporation
    Inventors: John W. Spaniol, Ronald E. Tollum, Julius A. Barthelme
  • Patent number: 4292465
    Abstract: A distributed processing telex switch having different levels of processor control to handle the calls between terminations connected to the exchange is disclosed. A common control processor occupies the highest level of processor control and function as the system-wide manager. Next below common control is a plurality of master control processors which function to switch the command data between common control and the lower levels of processor control, and to handle the conversation data generated by each of the terminations connected to the exchange. Each master control processor controls a predetermined number of termination from among all of the terminations connected to the exchange. Connected to each master control processor is a plurality of group control processors which control the flow of data to and from a second predetermined number of terminations from among the terminations controlled by each master control processor.
    Type: Grant
    Filed: November 6, 1979
    Date of Patent: September 29, 1981
    Assignee: Frederick Electronics Corporation
    Inventors: John F. Wilson, Edward D. Hoover, Philip K. Hammond, William A. Moshier, Jack L. Woodell, John W. Spaniol, John J. Bowerman, Larry C. Bieber, Marvin Perlman
  • Patent number: 4288658
    Abstract: A system for generating telex signaling sequences in each termination line in a group of customer termination is disclosed. The system includes a multi-line high-speed line control processor which transmits to and receives from each customer termination, data signals indicative of the signaling levels in the termination lines. The line control processor controls the termination signals by executing, in a time share mode, selected signaling routines for each termination. Connected between the line control processor and the customer terminations is a terminator controller means for selecting the termination currently being time share processed to input to or receive signals from the line control processor. Also connected to the line control processor is a group control processor which supervises the generation of the signaling sequences in each termination by executing script task routines.
    Type: Grant
    Filed: November 6, 1979
    Date of Patent: September 8, 1981
    Assignee: Frederick Electronics Corporation
    Inventors: Larry C. Bieber, Jack L. Woodell
  • Patent number: 4107612
    Abstract: A phase locked loop signal generator is especially adapted for synthesizing a selectable frequency signal for exciting an HF radio frequency transmitter to transmit over the seven marine telegraph bands. The signal generator includes an oscillator for providing a highly stable frequency standard. Another signal generator is responsive to the frequency standard and to frequency selector signals input by the operator for generating an exciter signal which is coupled to the transmitter for effecting the RF transmission within a predetermined frequency range.
    Type: Grant
    Filed: May 5, 1976
    Date of Patent: August 15, 1978
    Assignee: Frederick Electronics Corporation
    Inventor: J. Howard Leveque