04631467 is referenced by 10 patents and cites 5 patents.

A variable-frequency, variable-voltage (VVVF) converter is interposed in the line between an AC source and an asynchronous escalator motor. Current to the motor is sensed to determine load in conjunction with a passenger detector and load simulating electronic system and the frequency and voltage of the converter are automatically adjusted in response thereto to control escalator speed. The system includes a converter to supply the asynchronous drive motor of the escalator with variable frequency and an appropriate control circuit for manual or automatic operation of the escalator at different speeds, which is equivalent to different motor frequencies.

Title
Escalator passenger flow control
Application Number
6/738336
Publication Number
4631467
Application Date
May 28, 1985
Publication Date
December 23, 1986
Inventor
Detlev Abraham
Berlin
DE
Dietrich E Herrmann
Vechelde
DE
Agent
Gerald E Linden
Assignee
Otis Elevator Company
CT, US
IPC
H02P 5/40
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