Abstract: A method and apparatus for detecting imperfections in a semi-conductive strand shield applied to an electrical conductor. The method comprises the steps of applying AC current between a bare portion of the conductor and apparatus applying a jacket of insulating material over the strand shield, as the conductor and shield move through the apparatus. The current and the voltage applying the current are measured to determine the impedance of the circuit of the conductor and apparatus applying the insulating jacket. Changes in the impedance are then monitored, such changes being indicative of changes in the quality of the strand shield applied to the conductor.

Abstract: A control method and circuit providing smooth transition between two regulating modes involving two regulating parameters, one active and one inactive. The method comprises the steps of providing a reference signal and developing a signal representing the inactive parameter. The two signals are then compared to provide an inactive output signal that is indicative of any difference existing between them. Another signal is developed that represents the active parameter, and this signal is compared to the inactive output signal. The inactive output signal is then forced continuously to the value of the signal representing the active parameter when the values of the two signals are different. Change from the one parameter and mode to the other parameter and mode can now be made without a disturbing effect.