Finland's Relations with the Soviet Union, 1940-1986

A control system for a rock crusher in a rock crushing plant operates the crusher at optimum efficiency for increasing the throughput of the crusher. The horsepower of the motor that drives the crusher is sensed, and the level of rock within the crusher bowl is sensed, and these sensed conditions are inputted into a programmable logic controller. The programmable logic controller correspondingly adjusts the feed rate of a feeder that supplies rock to the crusher. The controller also commands a bypass component positioned between the feeder and crusher adjacent the mouth of the crusher for providing an immediately responsive control of the feed rate being delivered to the crusher.