Elevator control system
US4213517A · kind A · utility
7Cited by
3References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 6, 1978 |
| Grant date | Jul 22, 1980 |
| Priority date | — |
| Expiry date | Jul 6, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B1/308
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An elevator control system includes a power source which supplies AC power to an induction motor for driving an elevator car through a first thyristor gate circuit. Another induction motor provided for braking the elevator car is connected to the power source through a second thyristor gate circuit. A tachometer generator connected to the induction motors produces an speed signal indicative of the speed of the elevator car. The speed signal is compared with a reference signal and the difference therebetween is used to control the first and second thyristor gate circuits for controlling the elevator car speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.