[en] Theoretical and experimental studies on a possibility of using the automatically controlled cross field for increasing the maximum gas kinetic plasma pressure in a three-turn stellarator are performed. Within the framework of a simplified theoretical model various laws of cross field control using feed--- back are analysed. It is shown that the control scheme based on magnetic measurements can ensure necessary accuracy of maintaining equilibrium near the optimum. Experimental data concerning equilibrium effects obtained at the stellarator ''URAGAN'' are in a satisfactory agreement with the theory