Peak Value Of Current Pulse Research Articles

The discharge selectivity in an atmospheric pressure helium–argon dielectric barrier discharge

In this paper, an atmospheric pressure polyethylene terephthalate dielectric barrier discharge is produced in a helium–argon mixture. The influences of the electrode voltage on the discharge mode are experimentally investigated. The results show that, at a fixed argon content of 50%, the discharge transits from local uniform, through the isolated pattern, to whole uniform with the increase in the electrode voltage. Both the peak value of current pulse and argon spectra (696.54, 763.13, 772.09, 811.17, and 911.81 nm) intensities are captured to clarify the characteristics of the discharge mode transition. The different discharge characteristic regions are obtained by varying the argon content. In addition, the influence of the argon content on the above-mentioned argon spectra intensities is also researched. The spectra intensities enhance at 696.54, 763.13, and 772.09 nm but weaken at 811.17 and 911.81 nm with the increase in the argon content when the discharge operates in the whole uniform mode. The physical reasons for these results are discussed.

Modeling the dependence of the negative corona current density on applied voltage rise time

In this paper, a numerical simulation is used to investigate the influence of applied voltage rise time on negative corona current characteristics in SF6 at atmospheric pressure. There were 23 particle species and 67 kinds of reactions considered in plasma chemical reactions. The influence of different rise times of the applied voltage is investigated. The spatial distributions of the radial electric field and total density of electrons and positive and negative ions, at and after the inception time of the corona current pulse, are used to explain the role of the rise time of the applied voltage on the mechanism of corona current pulse formation. It is found that the corona inception time, inception voltage, peak value of current pulse, number of sub-current pulses, and the time between the sub-pulses are strongly affected by the movement of negative ion clouds produced by the attachment. The quantitative analysis of the negative ions shows that the light ions preceded the heavy ions in their motion far away from the cathode and that this motion is governed by the rise time of the applied voltage.

Analysis and Comparison of Audible Noise Caused by Magnetic Components in Switch-Mode Power Supplies Operating in Burst Mode and Frequency-Foldback Mode

In this paper, it is theoretically shown and experimentally verified that operation of switch-mode power supplies in burst mode (BM) results in lower audible noise than operation in frequency-foldback mode (FFM). However, the selection of the switching frequency in a burst package can have a significant impact on the audible noise. In both BM and FFM, the audible noise can be reduced by decreasing the peak value of current pulses and proportionally increasing the burst frequency in BM and the switching frequency in FFM. In BM, the audible noise can be further reduced if instead of increasing the burst frequency, the number of burst pulses is increased without changing the burst frequency. The presented BM and FFM audible noise analyses are experimentally verified on a dc–dc boost test circuit.