Signal Transformations for Analysis of Supraharmonic EMI Caused by Switched-Mode Power Supplies

Switched-Mode Power Supplies (SMPSs) are a relevant source of conducted emissions, in particular in the frequency interval of supraharmonics, between 2 kHz and 150 kHz. When using sampled data for assessment of compliance, methods other than Fourier analysis should be considered for better frequency resolution, compact signal energy decomposition and a shorter time support. This work investigates the application of the Wavelet Packet Transform (WPT) and the Empirical Mode Decomposition (EMD) to measured recordings of SMPS conducted emissions, featuring steep impulses and damped oscillations. The comparison shows a general accuracy of the amplitude estimate within the variability of data themselves, with very good performance of WPT in tracking on stationary components in the low frequency range at some kHz. WPT performance however may vary appreciably depending on the selected mother wavelet for which some examples are given. EMD and its Ensemble EMD implementation show a fairly good accuracy in representing the original signal with a very limited number of base functions with the capability of exploiting a filtering effect on the low-frequency components of the signal.

Comparative analysis of positive output super lift DC-DC luo converters

<p>Due to the advancement in the semiconductor technologies, DC-DC converters are gaining the importance in several industrial applications. They form the core of the switched mode power supplies which are used in real time applications. The performance of the conventional converter is affected by the parasitic elements and their voltage gain is also limited. To improve upon this, Super lift converters converter were developed by Luo. Voltage lift technique increases the voltage in geometric progression .These super lift converter are classified as positive output and negative output which are further classified into different series. In this paper series of Positive output Super lift converter topologies are analyzed. The proportional –integral controller is employed to theses converter in the paper. These converters boost the voltage up to three times the input voltage and gaining importance in Electric vehicles and Solar powered applications. The simulations are carried in PSIM.</p>

Design of a Dispensing CNC Device

<span style="font-family: 'Times New Roman',serif; font-size: 10pt; -ms-layout-grid-mode: line; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-GB">This article deals with the design and practical realization of a CNC device designed for the application of viscous materials, such as a thermal conducting paste. Paste is used for effective heat transfer what is essential in switched mode power supplies. However, its application on surface can be an issue. Designed CNC device serves for easier and more accurate application in production process using standard tubes.</span>