CIRCUITS ARE DISCLOSED TO CONTROL THE POWER SUPPLY FURNISHING D.C. VOLTAGE TO A PLURALITY OF ELECTROMAGNETIC WHORL TENSION DEVICES WHICH CONTROL THE TENSION OF A PLURALITY OF YARNS DURING THE PRODUCTION OF A BEAM BY A WARPER. FIVE VOLTAGE LEVEL CONTOLS, FIVE ADJUSTABLE TIMING CONTROLS AND TWO RAMP VOLTAGE CONTROLS ARE DISCLOSED TO ENABLE THE APPLICATION OF THE TENSION TO THE PLURALITY OF YARNS TO BE WITHIN CLOSE TOLERANCES OF A SELECTED RUNNING TENSION LEVEL DURING THE STARTING, RUNNING AND STOPPING OF THE BEAMING OPERATION.