Automatic Control of the Trim-Coil Power Supplies at the Berkeley 88-Inch Cyclotron

The automatic-control requirements of the 88-inch cyclotron trim-coil power supplies resemble those of many industrial processes. Certain set points must be automatically realized and maintained throughout an extended experimental run. The recently installed system reduces trim-coil setup time to less than 5 min, and maintains these set points within 0.4% or less over an 8-hour period. Although the system is primarily analog, the set points for a run are programmed on an IBM card and entered into the system through a digital-to-analog interface. The system is being extended to include the many machine-parameters--such as the deflector positions and voltages--that have set points.