公开(公告)号：US3568027A

公开(公告)日：1971-03-02

申请号：US3568027D

申请日：1969-11-18

Applicant: IBM

Inventor： BACON JAMES L ,  CLEAVE GEORGE W

IPC: H02P7/06 ,  H02P7/288 ,  H02P5/16

CPC classification number: H02P7/288 ,  H02P7/2885 ,  Y10S388/902 ,  Y10S388/91 ,  Y10S388/917 ,  Y10S388/934

Abstract: The invention concerns a motor control circuit especially useful with small direct-current-type motors and featuring a symmetrical circuit topology that achieves motor regulation and temperature compensation in a simplified manner. The circuit includes an upper portion comprising a motor model section for establishing a reference voltage to determine the speed of the motor, a parallel circuit section including the motor itself, a lower section intended for detection of current changes in the motor section, and a difference amplifier interconnected with the motor model and motor sections for maintaining an essentially zero potential difference between these sections. The symmetrical layout achieves a highly accurate measure of control over motor speed once a nominal speed has been established. Due to the symmetrical configuration of the circuit, effects of temperature and humidity are essentially eliminated. Some provision is made for alternative ways of controlling the desired motor speed including a variable control for changing motor speed in a regular fashion throughout a desired range of speeds.