Variable current speed controller for eddy current motors

Patent · Fri Mar 12 04:00:00 EST 1982

OSTI ID:6570518

Gerth, H L; Bailey, J M; Casstevens, J M; Dixon, J H; Griffith, B O; Igou, R E

A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

• DOE Contract Number: W-7405-ENG-26
• Assignee: ERA-08-018421; EDB-83-051177
• Patent Number(s): None
• Application Number: ON: DE83006862
• OSTI ID: 6570518
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420200* -- Engineering-- Facilities
Equipment
& Techniques
CONTROL EQUIPMENT
CONTROL SYSTEMS
CURRENTS
DESIGN
ELECTRIC CURRENTS
ELECTRIC MOTORS
EQUIPMENT
LATHES
MACHINE TOOLS
MECHANICAL VIBRATIONS
MIRRORS
MOTORS
SPEED REGULATORS
SURFACE FINISHING
TOOLS