RLC circuit

About: RLC circuit is a research topic. Over the lifetime, 14490 publications have been published within this topic receiving 142697 citations.

Off line resonant converter with merged line rectification and power factor correction

Abstract: An off line resonant converter with improved power factor and merged line rectification is disclosed. An example off line resonant converter includes a boost storage inductance circuit to be coupled to receive an ac input line voltage. A switcher circuit is coupled to the boost storage inductance circuit. The switcher circuit includes stacked first and second passive switching devices coupled to the boost storage inductance circuit. The switcher circuit further includes stacked first and second active bidirectional switching devices coupled to the stacked first and second passive switching devices. The stacked first and second active bidirectional switching devices are controlled to generate a square wave signal and to alternately store energy in and receive energy from the boost storage inductance circuit such that a pulsating current is conducted between the boost storage inductance circuit and the switcher circuit. The pulsating current is bidirectional and flows in a first direction when the ac input line voltage is at a first polarity. The pulsating current flows in an opposite second direction when the ac input line voltage is at a second polarity. A resonant circuit is coupled to an output of the switcher circuit to receive the square wave signal from the switcher circuit to generate an output of the resonant converter.

Transistor conduction-angle control for a series-parallel resonant converter

Abstract: A DC to DC series-parallel resonant converter (10) having a plurality of switches (Q1-Q4) which are switched alternatively between on and off states to cause electrical current to flow alternatively in first and second directions through a series-resonant circuit (60) Including a variable frequency ramp generator (28) having a reset input (R) for casuing an output ramp signal produced at an output to drop to zero in response to each reset signal; a comparator (30) having an input coupled to the output of the ramp signal generator, a second input for controlling the output DC voltage of the series-parallel resonant circuit and an output which changes level each time the ramp signal reaches the magnitude of the second input; a bistable circuit (32) having first and second outputs (Q, Q) for respectively outputting first and second signals, the output signals changing in response to a change in the output signal of the comparator coupled to the input; a pulse generator (26), coupled to the series-parallel resonant circuit for producing an output pulse train with an output pulse occurring each time the flow of current through the series-resonant circuit changes from one of the first and second directions to another of the first and second directions, the output pulses being applied to the reset input of the variable frequency ramp generator to regulate the frequency of the output ramp signal.

Position-Insensitive Wireless Power Transfer Based on Nonlinear Resonant Circuits

Abstract: Near-field resonant-based wireless power transfer (WPT) technology has a significant impact in many applications ranging from charging of biomedical implants to electric vehicles (EVs). The design of robust WPT systems is challenging due to its position-dependent power transfer efficiency (PTE). In this paper, a new approach is presented to address WPT’s strong sensitivity to the coupling factor variation between the transmit and receive coils. The introduced technique relies on harnessing the unique properties of a specific class of nonlinear resonant circuits to design position-insensitive WPT systems that maintain a high PTE over large transmission distances and misalignments without tuning the source’s operating frequency or employing tunable matching networks, as well as any active feedback/control circuitry. A nonlinear-resonant-based WPT circuit capable of transmitting 60 W at 2.25 MHz is designed and fabricated. The circuit maintains a high PTE of 86% over a transmission distance variation of 20 cm. Furthermore, transmit power and PTE are maintained over a large lateral misalignment up to ±50% of the coil diameter and angular misalignment up to ±75°. The new design approach enhances the performance of WPT systems by significantly extending the range of coupling factors over which both load power and high PTE are maintained.

Rf connector for connecting a mobile radiotelephone to a rack

Abstract: An RF connector for connecting a radiotelephone (1) to an external antenna, whereby the telephone and a corresponding device rack (2) are connected to the external antenna by two pairs of matching metal plates (1a, 2a, 1b, 2b) that provide a capacitive two-wire connector-interface. In order to avoid too large a size and too high an attenuation, a coil (3a, 3b) is connected in series with the pair of plates (1a, 2a; 1b, 2b) constituting each capacitor. The coil and capacitor are dimensioned so that they form a resonant circuit with an attenuation of nearly 0 at the desired transmission frequency. A first balancing transformer (4) before the resonant circuit transforms the signal into a balanced signal, and a second balancing transformer (5) after the resonant circuit transforms the signal back to an unbalanced signal to be transmitted further on a coaxial cable.

Method for processing traffic data in a wireless communications system

Abstract: The present invention concerns a method of processing traffic data in Layer 2 of a wireless communications system, whereby the MAC layer is arranged, after receipt of a traffic data volume report from the RLC layer, to process said data volume report and to then issue an acknowledgement message to the RLC layer. The method ensures that the RLC and MAC layers are synchronised with respect to traffic data processing. The MAC layer may be arranged to issue an acknowledgement to the RLC layer only where it determines from processing a data volume report that the RLC layer is not permitted to transmit data in a next or subsequent corresponding TTI. The present invention also concerns a process for data discard in a Radio Link Control (RLC) layer of a Wideband Code Division Multiple Access (WCDMA) wireless communications system such as a Universal Mobile Telecommunications System (UMTS). The process involves, responsive to the triggering of a data discard operation, determining whether the RLC layer is permitted to transmit data. Where it is determined that the RLC layer is not permitted to transmit data in a next or subsequent TTI, the method includes the step of informing the RLC layer that data is not required.