Power distribution control in bipolar low-pressure glow discharge process - with controllable superimposed direct current adjusted so that specified power distribution between the two electrodes is maintained.

Abstract
The process concerns control of the power distribution between two electrodes (2a,2b) in a bipolar low-pressure glow discharge installation driven by an alternating voltage and a superimposed direct voltage. The direct voltage is produced by a controllable four-quadrant direct voltage source (6). One terminal of this source is connected to the alternating current source (5), while the other terminal is connected to the electrode (2b). Dependent on a parameter of the glow discharge process and the coating task, the direct voltage is controlled and/or adjusted so that a specified ratio of power distribution between the two electrodes is maintained. USE - Used for surface treatment, cleaning and coating. ADVANTAGE - Static and dynamic control of the power distribution can be exerted over a broad frequency range and at high power levels. Very accurate maintenance of process parameter is possible.