公开(公告)号：DE2446293A1

公开(公告)日：1975-10-16

申请号：DE2446293

申请日：1974-09-27

Applicant: NAT RESEARCH DEV CORP LONDON

Inventor： HURLE DONALD THOMAS JAMES ,  JOYCE GORDON CHARLES

IPC: C30B15/28 ,  G05B11/32 ,  B01J17/18

Abstract: In crystal growing apparatus in which a crystal is vertically pulled from an electric heated melt the weight of the crystal is measured by a load cell whose output is compared with an expected function to form a control loop for controlling heater power, the improvement comprises a correction circuit for applying to the control loop a signal compensating for a time differential ( lambda a) of an error signal in the load cell output. The correction circuit may be a feedback or a feed forward loop.