Hoist control system utilizing reversible, variable speed induction motor
Abstract
Abstract APPARATUS FOR CONTROLLING THE MOVEMENT OF A HOIST IN A LATERLA DIRECTION BY MEANS OF A REVERSIBLE A.C. INDUCTION MOTOR. A CIRCUIT SUPPLIES A.C. POWER TO THE MOTOR, THE CIRCUIT INCLUDING A TRIGGERABLE SEMICONDUCTOR CURRENT SWITCHING DEVICE FOR VARYING THE AVERAGE POWER SUPPLY TO THE MOTOR IN RESPONSE TO VARIATIONS IN THE PHASE OF TRIGGERING. A CONTROLLER INCLUDES MANUALLY OPERATED SWITCH MEANS AND MEANS FOR GENERATING A D.C. REFERENCE SIGNAL, THE AMPLITUDE OF WHICH CHANGES LINEARLY IN RESPONSE TO OPERATION OF THE SWITCH MEANS. MEANS IS PROVIDED WHICH IS RESPONSIVE TO THE RELATIVE AMPLITUDES OF THIS D.C. REFER- ENCE SIGNAL AND A D.C. FEEDBACK SIGNAL VARYING WITH THE SPEED OF THE MOTOR, FOR VARYING THE PHASE OF TRIGGERING OF THE SWITCHING DEVICE TO CHANGE THE MOTOR SPEED LINEARLY, PROVIDING SUBSTANTIALLY CONSTANT LATERAL ACCELERATION OF THE HOIST.
Inventors
- 👤 John P Truemper
Bibliographic Details
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