公开(公告)号：US3584232A

公开(公告)日：1971-06-08

申请号：US3584232D

申请日：1969-01-21

Applicant: BELL TELEPHONE LABOR INC

Inventor： WALLACE ROBERT L JR

IPC: G06G7/24

CPC classification number: G06G7/24

Abstract: Precision logarithmic conversion is achieved by utilizing a serial connection of Schottky barrier diodes in conjunction with an operational amplifier. Deviation from the desired logarithmic characteristic because of diode limitations, namely, reverse-bias saturation current, forward-bias resistance, temperature dependence and the like, is minimized by selectively supplying compensating signals into the input and output circuitry of the amplifier.

公开(公告)号：US3502811A

公开(公告)日：1970-03-24

申请号：US3502811D

申请日：1967-12-11

Applicant: BELL TELEPHONE LABOR INC

Inventor： SCHROEDER MANFRED R ,  WALLACE ROBERT L JR

IPC: H04R1/40 ,  H04R1/20 ,  H04R1/34

CPC classification number: H04R1/406

公开(公告)号：US3644674A

公开(公告)日：1972-02-22

申请号：US3644674D

申请日：1969-06-30

Applicant: BELL TELEPHONE LABOR INC

Inventor： MITCHELL OLGA M M ,  ROSS CAROLYN ,  WALLACE ROBERT L JR

IPC: G10K11/178 ,  H04M9/00 ,  H04R3/00 ,  H04B15/00

CPC classification number: H04R3/005 ,  G10K11/178 ,  G10K2210/108 ,  G10K2210/1082 ,  G10K2210/111 ,  G10K2210/3012 ,  G10K2210/3045 ,  H04M9/001

Abstract: Signals from a desired source, such as a person speaking, are enhanced relative to unwanted ambient sound by a speech processor that includes an array of microphones arranged at equal distances from the desired source. The unwanted sound, being ''''off-center, '''' arrives nonconcurrently at the individual microphones. The processor continuously arranges the instantaneous microphone outputs in order of their relative energy contained, and selects as its output some one of the microphone outputs that is intermediate in the instantaneous ranking.

公开(公告)号：US3585528A

公开(公告)日：1971-06-15

申请号：US3585528D

申请日：1968-10-28

Applicant: BELL TELEPHONE LABOR INC

Inventor： WALLACE ROBERT L JR

IPC: H01L43/04 ,  H03B19/00 ,  H03C3/12 ,  H03C1/48

CPC classification number: H03B19/00 ,  H01L43/04

Abstract: In practical Hall-effect modulators, unwanted signal components, for example, carrier frequency harmonics and magnetic field components, appear in the output signal. These unwanted signal components are suppressed by selectively shaping a face of a magnetic core member of the modulator to introduce an inhomogeneity into the magnetic field applied to the Hall element. Further suppression of unwanted signal components is achieved by utilizing a potentiometer connected between output terminals of the Hall element and an additional terminal substantially in the center of the element.