RLC circuit

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

Bilateral series resonant inverter for high frequency link UPS

Abstract: A description is given of a bilateral series-resonant inverter for high-frequency link uninterruptible power supply. The inverter consists of a zero-current-switched series-resonant power converter, a high-frequency transformer, and a zero-current-switched cycloconverter, whereby bidirectional power flow is possible and high efficiency is obtained. The output voltage is regulated by controlling the resonant tank energy, and the switching pattern of the cycloconverter is fixed to obtain the high-frequency transformer. A novel control scheme to minimize the output ripple voltage is suggested and verified through computer simulation, and the effects of the circuit parameters on the output voltage ripple are discussed. >

Ultrahigh-frequency high-impedance passive voltage probe

Abstract: The most commonly used type of voltage probe for high-bandwidth applications is the high-impedance passive probe. It is reliable, rugged, simple to use, and inexpensive. However, because it has a relatively high input capacitance, it is not truly “high impedance” to the higher frequency components of a test signal. Consequently, connecting the probe can distort the signal under test (e.g., by increasing the rise and fall times of a fast pulse). Also, the probe input capacitance forms a resonant circuit with any parasitic inductance in the probe ground lead. In response to a short-duration step in voltage, this can cause spurious oscillations in the input signal to the instrument. Active probes generally have a much lower input capacitance, thereby minimizing these problems. Also, active probes have been able to achieve much higher bandwidths than those of high-impedance passive probes. But active probes are very expensive, and they are not as rugged or as reliable as passive probes. They also require a power source, and they can introduce a DC offset error to the measured signal. The present invention is for circuitry that greatly increases the bandwidth of high-impedance passive probes. The invention employs a plurality of separate circuit paths for the AC components of a test signal to bypass the attenuating resistor at the probe tip. This circuitry also increases the input impedance for the higher frequency components of a test signal. Thus the invention allows the design of high-impedance passive probes that are competitive in performance with active probes while retaining the much lower cost, and the other inherent advantages, of passive probes. Also disclosed, are voltage probes with selectable attenuation factors of specific values that combine user convenience with relatively high bandwidth.

A wirelessly-controlled piezoelectric microvalve for regulated drug delivery

Abstract: This paper reports a novel wireless control of a normally-closed piezoelectric microvalve activated by a wireless inductor-capacitor (LC) resonant circuit, and enabled by an external magnetic field. The LC circuit is formed by connecting a multilayer coil to a piezoelectric actuator (PEA) that behaves as a capacitor and a resistor in parallel. The LC circuit is activated by modulating the field frequency to its resonant frequency ( fr ) of 10 kHz, which matches the optimal operating frequency of the device, while considering the resonant frequency of the PEA. The working fluid is stored in an 88.9 μL polydimethylsiloxane balloon reservoir that pumps the liquid due to the difference in pressure, which eliminates the need for a pump. The design of the device was optimized using several analytical and experimental approaches. This device was fabricated using a time and cost-effective out-of-clean-room fabrication process. The valving performance was initially characterized in air, then in phosphate buffered saline (PBS) solution to mimic the drug release kinetics into human interstitial body fluids. Maximum flow rate values of 8.91 and 7.42 μL/min are achieved in air and PBS solution respectively, at a maximum input pressure value of ∼13 kPa. A programmed short-term delivery of desired liquid volumes in separate batches shows that the volumes are delivered into air and PBS solution with maximum percentage errors of 7.49% and 7.91%, respectively. Additionally, a programmed 3-day long-term reliability test shows that the device was able to achieve desired flow rate values between 160 and 320 μL/day in air and PBS solution with a maximum percentage error of 3.11% and 4.39%, respectively. The results show that the developed device has high potential to be used in drug delivery applications.

Phase-shifted resonant converter having reduced output ripple

Abstract: A power converter (100) comprises a pair of resonant converter circuits 112-115, 132, 136, 138, 146 and 116-119, 134, 142, 144, 148) coupled together in parallel and operated at respective switching frequencies that are out of phase. The power converter includes a first resonant converter circuit and a second resonant converter circuit operatively coupled together. The first resonant converter circuit (112-115, 132, 146, 136, 138) includes at least one power switch (112, 114) adapted to convey power to a first resonant circuit (132, 146, 136, 138) and a first rectification (152, 154) stage adapted to rectify the conveyed power from the first resonant circuit. The second resonant converter circuit (116-119, 134, 148, 142, 144) includes at least one power switch (116, 118) adapted to convey power to a second resonant circuit (134, 148, 142, 144) and a second rectification stage (156, 158) adapted to rectify the conveyed power from the second resonant circuit. A filter capacitor (162) is coupled to the first and second rectification stages to provide DC output power therefrom. A regulator (126) is operatively coupled to the first and second resonant converters to control.

Generalized traveling-wave-based waveform approximation technique for the efficient signal integrity verification of multicoupled transmission line system

Abstract: As very large scale integration (VLSI) circuit speed rapidly increases, the inductive effects of interconnect lines strongly impact the signal integrity of a circuit. Since these inductive effects make the signal integrity problems much more serious as well as intricate, they become one of the critical issues in today's high-speed/high-density VLSI circuit design. In this paper, a generalized traveling-wave-based waveform approximation (TWA) technique is presented which can be accurately as well as efficiently employed for the signal integrity verification of the inductively dominated (moderate Q) multicoupled RLC transmission line system. The technique is composed of three steps. First, the signals in the multicoupled (n-coupled) transmission line system are decoupled into n-isolated eigen-modes (i.e., basis vectors). Next, the slow-transient low-frequency characteristics of the system response are determined, approximately, in the frequency-domain by using the dominant poles of the basis vectors. Finally, the fast-transient high-frequency characteristics of the system response are calculated in the time domain by using the traveling wave characteristics of the basis vectors. It is shown that the time-domain responses of the multicoupled RLC transmission line system can be accurately as well as efficiently modeled with the generalized TWA technique. Then, in inductance-dominant multicoupled interconnect networks, switching-dependent signal integrity, i.e., signal delay, crosstalk, ringing, and glitches are investigated extensively with the proposed technique.