Patent · US Active

Safe control of a brake using low power control devices

US8585158B2 · kind B2 · utility

5Cited by

25References

28Claims

0Family size

Assignee

OTIS ELEVATOR COMPANY · US

Inventors

Juergen Gewinner · Berlin, DE
Marvin Dehmlow · Berlin, DE

Key dates

Filing date	Jun 17, 2008
Grant date	Nov 19, 2013
Priority date	—
Expiry date	Apr 20, 2029

Classification

Technology area (CPC H)Electricity
CPC primaryH02M3/33523
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A control circuit selectively energizes a load, such as an elevator or escalator brake (12). The circuit includes a transformer (28) with a primary-winding connected to a series with a semiconductor switch (40) that is driven by a pulse width modulation (PWM) controller. Power to the PWM controller is supplied through safety relay contacts (52A, 52B). When the load is to be energized, the safety relay contacts are closed and the PWM controller drives the semiconductor switch to supply energy through the transformer to the secondary circuit. A command signal to secondary circuitry (64) causes power in the secondary to be applied to the load (12). If the safety relay contacts open, the PWM controller turns off and power is no longer delivered to the secondary circuit and the load.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.