Keywords: plasma applications, DC pulse power supply, switching sequences, microcontrollers
A DC-pulse power supply for plasma applications
A DC-pulse power supply designed for plasma applications is presented in this paper. It consists of an H-bridge switching circuits and two DC sources. All pulse parameter values are set in a control panel developed with LabVIEW software. The designed panel adopts RS232 protocol to sequentially transmit the set parameter values to a low-cost 8-bit microcontroller, AT89C51. The microcontroller controls the switching sequences of the H-bridge circuit and the voltage of DC sources. Depending on the user's requirements, the designed power supply can offer positive and negative pulse trains, unipolar and bipolar pulse trains, symmetric and asymmetric pulse trains and other asymmetric pulse trains. The adjustable pulse parameters include pulse dominant time, recessive time, pulse levels and pulse numbers. Experimental results demonstrate that the desired pulsing functions of DC-pulse power supply are all achieved.