Larry B Bishop

US Patent:

42031419, May 13, 1980

Filed:

Mar 30, 1978

Appl. No.:

5/891531

Inventors:

Larry D. Bishop - Colleyville TX
Jack C. Parker - Bolingbrook IL

Assignee:

Wescom, Inc. - Downers Grove IL

International Classification:

H02H 308

US Classification:

361 18

Abstract:

A current regulator for a pulse code modulated (PCM) transmission line is interposed between a voltage potential and a load (consisting of repeater amplifiers along the PCM transmission line) for limiting the current flow to the load. During normal operation, the regulator provides a relatively low impedance path from the voltage potential to the load through a series pass transistor and a sensing resistor. During an overload condition, which is sensed by the sensing resistor, the series pass transistor is deprived of base drive thereby providing a high impedance path with an accompanying increased voltage drop across the series pass transistor of the series regulator. This voltage drop is used to drive a timer which turns the series pass transistor off and on, with a low on time or duty cycle, in order to minimize power dissipation during the overload condition. After the overload condition has been alleviated, the series pass transistor is turned back on by the timer, and due to the low current flowing to the load, the series pass transistor is again returned to its relatively low impedance conducting condition.

US Patent:

43934927, Jul 12, 1983

Filed:

Feb 17, 1981

Appl. No.:

6/234797

Inventors:

Larry D. Bishop - Colleyville TX

Assignee:

Reliance Electric Co. - Cleveland OH

International Classification:

H04J 308
H04J 314

US Classification:

370 15

Abstract:

A multi-channel digital subscriber carrier system for serving a multiplicity of subscribers one or more of whom may be located at points between the central office and the subscriber (furthest remote) terminal. One or more drop terminals are provided to serve these inbetween subscribers. Each terminal has a receiver section for recovering the clock signal generated by a master oscillator located in the central office. The receiver section also synchronizes on the received signal and generates signals indicating times of occurrence of the channels in the received signal. The transmitter section of each terminal uses the above signals and the recovered clock to generate a digital signal wherein messages from the subscribers at the terminal are inserted in those channels associated with the subscribers for the messages received from the office for the subscribers. Each terminal has associated therewith a circuit for bypassing the terminal upon the occurrence of a terminal fault condition. When the drop terminals are connected to the inward cable pair each terminal has associated therewith a circuit for looping back the system at the terminal upon the occurrence of a cable fault condition.

US Patent:

41608844, Jul 10, 1979

Filed:

Feb 6, 1978

Appl. No.:

5/875330

Inventors:

Larry D. Bishop - Colleyville TX

Assignee:

Wescom, Inc. - Downers Grove IL

International Classification:

H04B 344

US Classification:

179170J

Abstract:

A telephone transmission system has repeaters spaced along both the transmit and receive legs of the transmission line, with a power supply for the repeaters including a current regulator having positive and negative supply lines connecting the power supply to the two legs of the transmission line. Current surge protectors are connected from the two legs of the transmission line to ground. A pair of current sensors responsive to the current levels in the positive and negative supply lines, between the power supply and the current surge protectors closest to the power supply, produce output signals representative of the respective current levels. A control signal generating means receives the output signals from the current sensors and produces a control signal in response to a deviation of the higher current in the supply lines from a preselected reference level. The control signal is supplied to the current regulator to maintain the higher current level in the supply lines at the preselected reference level.