Inductor

About: Inductor is a research topic. Over the lifetime, 52565 publications have been published within this topic receiving 484068 citations. The topic is also known as: passive two terminal.

Fault Diagnosis of PWM DC–DC Converters Based on Magnetic Component Voltages Equation

Abstract: Switch fault diagnosis is an important design aspect for pulse width modulation (PWM) dc-dc power converters. It can prevent power converters from further damage, and also make preparations for remedial actions. In this paper, a fast switch fault diagnostic method is proposed for PWM dc-dc converters operating in continuous conduction mode. The proposed method utilizes the magnetic component (inductor or transformer) voltage for fault diagnosis. Based on the real-time voltage measurement and switch gate-driver signals, characteristics of switch open-circuit faults and short-circuit faults are rapidly extracted, and thus, switch faults can be quickly detected. The magnetic component voltage can be measured by an auxiliary winding in the magnetic core, and gate-driver signals can be easily got from the control circuit. Moreover, the fault detection can be implemented by a low-cost logical hardware circuit, and this circuit can be integrated into the control circuit. The fault diagnosis principle, design considerations, and implementation are discussed in this paper. Experiments are conducted to verify the theoretical analysis.

A 6.5 GHz monolithic CMOS voltage-controlled oscillator

Abstract: Phase noise and frequency tuning range are key performance parameters of high-frequency voltage-controlled oscillators (VCOs). To achieve low phase noise, LC sinusoidal oscillators with high quality factor (Q) are preferred to other topologies, such as inverter-based ring oscillators. The frequency tuning of LC oscillators can be readily achieved with varactor diodes either on-chip or external. The frequency tuning range is often limited by low supply voltage and maximum variable capacitance available to varactors at high frequencies when on-chip inductors are used. Other frequency tuning approaches include varying current in the resonator to alter effective capacitance, or varying relative weighting between two different LC resonators. While the former approach varies loop gain in addition to the phase, the latter requires careful choice of the resonators and their Qs for stable oscillations. This VCO architecture incorporates two coupled fixed-frequency LC oscillators to generate a variable-frequency output by varying the coupling between two oscillators.

Signal generating device and method for producing coagulation electrosurgical current

Abstract: A signal generating device and method for producing an RF output signal regulated in power and of decaying amplitude suitable for use in an electrosurgical generator for surgical coagulation purposes. The device includes a circuit tuned to a predetermined radio frequency suitable to prevent nerve stimulation and the tuned circuit has connected therewith an unregulated power supply with current through the tuned circuit being controlled by means of a solid state switching system. The tuned circuit includes an inductor initially charged to a predetermined energy level. The switching system is automatically controlled so that the switching system is repeatedly urged to the closed position at predetermined time intervals and remains in this position until the current through the tuned circuit reaches a predetermined level at which time the switching system is caused to open and the tuned circuit thereafter rings to produce a regulated output signal of decaying amplitude, this output being taken from the tuned circuit across a transformer and is well suited for surgical coagulation purposes wherein the electrical current passes from an electrode to body tissue in the form of an arc with power dissipation being far greater in the tissue than in the arc for best operation.

Regulated dc to dc converter

Abstract: A DC-DC converter includes first and second switches to be opened and closed at mutually exclusive times at a predetermined frequency. The first switch is connected to an inductor and a transformer primary winding so that a first current component from a DC input supply flows through it via the inductor. A second current component having a sinusoid component flows through the first switch in response to discharge of energy stored in a resonant circuit coupled to the transformer. The second component begins approximately simultaneously with closure of the first switch. The second switch, when closed, is connected so that a bidirectional current component flows through it in response to energy stored in the inductor. The rectifier is connected between the secondary winding and the load so the secondary winding supplies substantial current to the load.

Design and Analysis of Single-Stage Power Factor Correction Converter With a Feedback Winding

Abstract: A new single-stage power factor correction (SSPFC) converter is proposed for the adapter application, which is composed of a flyback converter, a feedback winding and a front-end input current shaper. Through the feedback winding, a direct energy transfer path is configured to improve the conversion efficiency and alleviate the voltage stress across the bulk capacitor. Moreover, the feedback winding is connected to the input through only two diodes, which results in low conduction losses. Equations and configurations are given to design the input current-shaping inductor and the magnetizing inductor of the transformer, which are operated in the discontinuous conduction mode (DCM) and the DCM/ continuous conduction mode boundary mode respectively for well-shaped current waveform and reduced bulk capacitor voltage. The theoretical analysis of the converter is verified by two SSPFC prototype circuits with 19 V/90 W output. One prototype achieves a high efficiency of 90.3%, while complying with IEC 61000-3-2 Class D standard. With a different turns ratio design, the power factor can be further improved to 0.97 in another prototype.