Abstract: A metal detector system which includes an electromagnetic search coil, a gate for diverting portions of a material stream containing metal detected by the search coil to a reject container, and a coupling for isolating vibrations caused by the gate from the search coil. The metal detector system also includes control circuitry for automatically recycling the gate when an obstruction prevents the gate from returning to its normal standby position. A test circuit is provided to test the search coil by closing a conductive loop passing through the electromagnetic field of the search coil.

Abstract: A control system for an electrically powered vehicle has thyristors acting as choppers and switches in its power circuit. An on-board digital computer provides gating pulses to the thyristors to control traction and auxiliary motors in accordance with programs responding to operator, circuit and vehicle condition signals. The programs provide for vehicle start-up, shutdown, regular operation, limited operation and maintenance.

Abstract: A searching method for optimizing the rate of penetration of a drill into a given medium based upon the two drilling parameters of thrust and speed of revolution. Preset base values of both parameters are input into the drilling control mechanism at the start of the process. Thereafter, based upon readings from an automatic penetration rate calculator, incremental changes are automatically made to one of the parameters, the other being held constant, until a maximized rate of penetration is established. Subsequently, the other parameter, previously held constant, is changed until a new maximized penetration rate is found. This optimized penetration rate searching is continuously and automatically effected until the drilling process is completed. The method additionally provides for the allowance of a wait period between successive incremental changes for accommodating response times of the system as well as instabilities which may occur as the result of nonlinear process dynamics.

Abstract: An apparatus employed in the searching of the optimized rate of penetration of a drill into a given medium based upon the two drilling parameters of thrust and speed of revolution. Preset base values of both parameters are input into the drilling control mechanism at the start of drilling. Thereafter, based upon readings from an automatic penetration rate calculator, the apparatus effects automatic incremental changes to one of the parameters, the other being held constant, until a maximized rate of penetration is established. Subsequently, the other parameter, previously held constant, is changed until a new maximized penetration rate is found. This optimized penetration rate searching is continuously and automatically effected until the drilling process is completed. The apparatus additionally provides for the allowance of a wait period between successive incremental changes for accommodating response times of the system as well as instabilities which may occur as the result of nonlinear process dynamics.