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Title: Elevator control apparatus

Abstract: An elevator car control apparatus is disclosed in which a three-phase AC tachometer generator is coupled to a motor for driving an elevator car, and the AC output of the tachometer generator is full-wave rectified for use as a speed feedback voltage. A waveform-shaping circuit generates one pulse for each cycle of the output of the AC tachometer generator. A counter counts such pulses after the car has passed a deceleration-initiating point, thereby producing the number of counts proportional to a car running distance after the passage of the deceleration-initiating point. From this number of counts, a deceleration command voltage decreasing progressively in accordance with car positions is obtained by a decoder and a digital-analog converter. During deceleration, the car-drive motor is subjected to feedback control in accordance with the difference between the speed feedback voltage and the deceleration command voltage, thus effecting deceleration control of the elevator car.


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Inventors: Ohira, Takeshi (Katsuta, JP)
Kameyama, Tadao (Higashiibaraki, JP)
Honzyo, Chihiko (Katsuta, JP)
Iwasa, Yuzaburo (Hitachi, JP)
Hatakeyama, Takanobu (Katsuta, JP)

Application Number: 871801
Filing Date: 1978-01-24
Publication_date: 1979-04-24
Assignee: Hitachi, Ltd. (JP)
Primary Class(es): 187/296
Other Classes:
US Patent Ref:
3090901May, 1963Shaw318/328.
3250975May, 1966Pepper318/328.
3531704Sep, 1970Uemura et al.318/328.
3728565Apr, 1973O'Callaghan318/618.
3764888Oct, 1973Anderson318/328.
3774729Nov, 1973Winkler187/29.
4024445May, 1977Tokuda et al.318/328.
4046229Sep, 1977Kernick et al.187/29.
4083431Apr, 1978Oohira et al.187/29.
4084662Apr, 1978Tezuka et al.187/29.

Other Refs:
Primary Examiner: Rubinson, Gene Z.
Assistant Examiner: Duncanson, Jr., W. E.
Attorney: Craig & Antonelli