A low power and low-phase noise quadrature voltage controlled oscillator (QVCO) using the differential complementary Colpitts oscillator topology has been developed. A transformer inductor is used to form a differential output oscillator and the back-gate coupling technique is used to generate quadrature outputs. The advantage of proposed QVCO is analyzed in terms of power consumption, phase no...

Limited Common-Mode Rejection Ratio (CMRR) in balanced interfaces often limits dynamic range in real-world audio systems. Conventional differential amplifier input circuits suffer serious CMRR degradation when driven by real system signal sources instead of laboratory generators. An ideal audio transformer, because of its extremely high common-mode impedances, is virtually immune to this degrad...

This paper presents an efficient wavelet and neural network (WNN) based approach for distinguishing magnetizing inrush currents from internal fault currents in three phase power transformers. The wavelet transform is applied first to decompose the current signals of the power transformer into a series of detailed wavelet components. The values of the detailed coefficients obtained can discrimin...

Second harmonic restraint is still commonly used to discriminate fault current and transformer inrush conditions. Such approach, however, has some disadvantages and limitations. Therefore various other criteria signals for power transformer inrush discrimination have been analysed. The paper presents a new multi-criteria stabilization algorithm that employs fuzzy reasoning technique for better ...

Risk assessment for power transformer is an important means to guide the condition based maintenance of transformer and enhance the reliability of power system operation, but also to strengthen the power transformer to provide an important basis for quality control. In this paper, an index system for comprehensive evaluation of transformer is put forward and a risk assessment model for power tr...

Transformer fault diagnosis and repair is a complex task that includes many possible types of faults and demands special trained personnel. In this paper, Petri Nets are used for the simulation of transformer fault diagnosis process and the definition of the actions followed to repair the transformer. An integrated safety detector relay is used for transformer fault detection. Simulation result...

According to the chronological literature survey, there exist three types of the on-chip transformer i.e the traditional on-chip passive transformer, the Distributed active transformer (DAT), and the CMOS gyrator-C active transformer (Yuan 2007). Formerly, there exist many review articles on the on-chip transformer. However, these articles focus on the on-chip passive transformer due to its ren...

Transformer is the power equipment of power system core. Intelligent monitoring and operation of transformer can not only monitor the full range of the transformer, the realization of state evaluation, it should be required repair, maintenance required good, but also on the latent fault early diagnosis and prediction. Research on transformer intelligent monitoring and operating technology of sa...

It may be well to point out explicitly that the networks considered in this paper and in the preceding papers are definitely not arbitrary nonlinear networks. Rather, it has been the aim to define nonlinear networks which share the uniqueness properties of passive linear networks. Physical considerations suggest that such networks may be aptly termed reliable networks. The networks considered h...