DC compact controller for speed-regulated conveyor belt - operates in hazardous atmos. on unidirectional or reversible conveyor with speed adjustment governed by loading data

摘要

A combination of electrical components affords infinitely adjustable speed control in accordance with the torque characteristics of DC motors for mine workings with fire-damp hazards. The rectifier, thyristor firing control, DC motor and process control computer are all protected against sparking. The motor is supplied from thyristor modules in an inverse-parallel bridge circuit for four-quadrant operation with bidirecitonal rotation and braking. USE/ADVANTAGE - In explosive atmos. of coal-mines. Stepless control of continuous or shuttle conveyors is achievable without groundwater pollution and at less cost than with induction motors.