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Inventor

William F. MacPherson

Inventor
DuPage, IL, US

Overview

9→
Patents
1977–1987
Patent span
Electricity
Primary field (CPC H)

Patents· 9 as inventor

Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.

H03Kprimary
H03KPulse technique38%
H04MTelephonic communication23%
H04QSelecting15%
H10DInorganic electric semiconductor devices15%
H02HEmergency protective circuit arrangements8%
PatentTitleYear
4,656,366'Control circuitry using two branch circuits for high voltage solid-state switches'19874,499,532'Floating battery feed circuit'19854,447,744'Control circuitry for high voltage solid-state switches'19844,408,248'Protection circuit'19834,345,163'Control circuitry for high voltage solid-state switches'19824,309,715'Integral turn-on high voltage switch'19824,250,409'Control circuitry using a pull-down transistor for high voltage field terminated diode solid-state switches'19814,166,931'Miniature bridge lifter for telephone lines'19794,021,617'Telephone ringer isolator'1977

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1977–1984Patents assigned to BELL TELEPHONE LABOR INC (7)· patent assignee history
1977Based in Warren, NJ, US· patent location history
1979–1987Based in DuPage, IL, US· patent location history
1983–1985Based in Wheaton, IL, US· patent location history
1985Patents assigned to AT & T BELL LAB (1)· patent assignee history
1987Patents assigned to AMERICAN TELEPHONE & TELEGRAPH (1)· patent assignee history

Inventor activity

Assignee and location history derived from the patent record.

Assignees
AssigneePatentsSpan
BELL TELEPHONE LABOR INC71977–1984
AMERICAN TELEPHONE & TELEGRAPH11987
AT & T BELL LAB11985
Locations
LocationPatentsSpan
DuPage, Illinois, US61979–1987
Wheaton, Illinois, US21983–1985
Warren, New Jersey, US11977