This paper describes incorporation of a piezoelectric transformer into a laptop computer adaptor in order to miniaturize the size and improve the energy utilization. Conventionally, electromagnetic transformer is used in the adaptor for generating the 45W output power. In this study, we show that a multilayer piezoelectric transformer rated 30W output power can satisfy the laptop specifications...

The gases generated in oil filled transformer can be used for determination of incipient faults. Dissolved gas analysis (DGA) of transformer oil has been one of the most power full methods to detect the faults. The various methods such as liquid chromatography, acoustic analysis, and transformer function techniques are require some experience to interpret observations. The researchers have used...

To study the voltage distribution in transformer windings under VFTO, a model for transformer windings has been developed based on Multi-conductor Transmission-Lines (MTLs) theory and the computing equations of the model based on FiniteDifference Time-Domain method (FDTD) is deduced. The Vector Fitting method is adopted to treat the frequency-dependent parameter by expanding the time-domain for...

Copper and aluminium are the two conductors most commonly used in transformer windings. This study presents a comprehensive comparison of distribution transformers built either with copper or with aluminium windings. The comparison is based on winding material conductivity, density, cost, connectivity, oxidation, machinability and behaviour under short-circuit. Additionally, a parametric analys...

This work presents a micromachined RF-CMOS transformer fabricated in a commercially available 0.18μm CMOS process. Maskless micromachining post-processing is used to remove oxide and substrate material from around the transformer, reducing parasitic effects and improving the performance of the transformer. Index Terms — baluns, CMOS integrated circuits; MEMS, maskless micromachining, Q enhancem...

In the present paper, a Transformer Design Optimization (TDO) software package is developed providing a user-friendly transformer design and visualization environment. This software consists of a collection of design optimization, visualization and verification tools, able to provide transformer designers all the proper interactive capabilities required for the enhancement of the automated desi...

We consider the problem of recovering the coefficient q(x) in the equation ut = ∆u− qu from boundary observations. Uniqueness of q based on knowledge of the ‘Neumann 7→Dirichlet response operator’ is shown as an implication of (known) corresponding results concerning the inverse problem for the corresponding hyperbolic equation wtt = ∆w − qw. This is then reduced to use of the response to a sin...

An on-chip transformer with a ferrofluid magnetic core has been developed and tested. The transformer consists of solenoid-type coil and a magnetic core of ferrofluid, with the former fabricated by MEMS technology and the latter by a chemical co-precipitation method. The performance of the MEMS transformer with a ferrofluid magnetic core was measured and simulated with frequencies ranging from ...

At high frequency, the winding losses of power transformer due to skin and proximity effects becomes a significant component in the loss calculation of the transformer efficiency. This paper examines the winding losses associated with these effects for planar-type low-profile transformers that are suitable for high frequency high density soft switching power supply application. The transformer ...

Transformer inrush currents are high-magnitude, harmonic-rich currents generated when transformer cores are driven into saturation during energization. These currents have undesirable effects, including potential damage or loss-of-life to the transformer, protective relay misoperation, and reduced power quality on the system. Controlled transformer switching can potentially eliminate these tran...