scholarly journals Quadrature Oscillators Using Operational Amplifiers

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Jiun-Wei Horng
Keyword(s):  
Phase Difference ◽  
Current Drive ◽  
Experimental Results ◽  
Operational Amplifiers ◽  
High Current ◽  
Output Impedance ◽  
Third Order ◽  
Oscillation Frequencies ◽  
Quadrature Oscillators ◽  
Circuit Configuration

Two new quadrature oscillator circuits using operational amplifiers are presented. Outputs of two sinusoidal signals with 90° phase difference are available in each circuit configuration. Both proposed quadrature oscillators are based on third-order characteristic equations. The oscillation conditions and oscillation frequencies of the proposed quadrature oscillators are orthogonally controllable. The circuits are implemented using the widely available operational amplifiers which results in low output impedance and high current drive capability. Experimental results are included.

scholarly journals Design and Experimental Evaluation of Quadrature Oscillator Employing Single FB–VDBA

2016 ◽  
Vol 67 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Abdullah Yesil ◽  
Firat Kacar ◽  
Koray Gurkan
Keyword(s):  
Experimental Evaluation ◽  
Active Element ◽  
Current Drive ◽  
Experimental Results ◽  
High Current ◽  
Output Impedance ◽  
Quadrature Oscillator ◽  
Theoretical Assumptions ◽  
Circuit Structure ◽  
Buffer Amplifier

Abstract This paper presents an attractive and a new voltage-mode quadrature oscillator using a single Fully Balanced-Voltage Differencing Buffer Amplifier (FB-VDBA) as the active element. The circuit structure is very simple, consisting of merely one FB-VDBA, one resistor and two capacitors. The circuit is implemented using the commonly available OPA860 which results in low output impedance and high current drive capability. The proposed circuit also has a suitable architecture for IC production. Experimental results which are matched well with the theoretical assumptions are given.

NEW CONSTRUCTION OF MIXED-MODE CHAOTIC CIRCUITS

2010 ◽  
Vol 20 (05) ◽  
pp. 1485-1497 ◽  
Author(s):  
KITDAKORN KLOMKARN ◽  
PITIKHATE SOORAKSA ◽  
GUANRONG CHEN
Keyword(s):  
Mixed Mode ◽  
Experimental Results ◽  
Operational Amplifiers ◽  
Third Order ◽  
Simple Scheme ◽  
New Construction ◽  
Suitable Combination ◽  
Chaotic Circuits

This paper presents a simple scheme for designing mixed-mode chaotic circuits using quadrature core oscillators. Two mixed-mode circuits are constructed by using a few operational amplifiers in suitable combination with some autonomous/nonautonomous second/third-order chaotic circuits. Simulation and experimental results have verified the simplicity and effectiveness of the new design.

scholarly journals Current-Mode Third-Order Quadrature Oscillator Using CDTAs

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jiun-Wei Horng
Keyword(s):  
Theoretical Analysis ◽  
Phase Difference ◽  
Oscillation Frequency ◽  
Current Mode ◽  
Third Order ◽  
Quadrature Oscillator ◽  
Oscillation Condition ◽  
Transconductance Amplifiers ◽  
Simulation Results ◽  
A Current

This paper describes a current-mode third-order quadrature oscillator based on current differencing transconductance amplifiers (CDTAs). Outputs of two current-mode sinusoids with90°phase difference are available in the quadrature oscillator circuit. The oscillation condition and oscillation frequency are orthogonal controllable. The proposed circuit employs only grounded capacitors and is ideal for integration. Simulation results are included to confirm the theoretical analysis.

Dual-Mode Quadrature Oscillator Using Current Follower Transconductance Amplifiers for GMI Sensors

2013 ◽  
Vol 712-715 ◽  
pp. 1886-1890
Author(s):  
Lei Zhang ◽  
Zhong Ming Pan
Keyword(s):  
Dual Mode ◽  
Transconductance Amplifier ◽  
Current Voltage ◽  
Sinusoidal Oscillator ◽  
Current Follower ◽  
Condition Of Oscillation ◽  
Transconductance Amplifiers ◽  
Passive Sensitivity ◽  
Quadrature Oscillators ◽  
Circuit Configuration

For designing GMI sensors, realization of current/voltage-mode (dual-mode) quadrature sinusoidal oscillator with the employment of current follower transconductance amplifier (CFTA) as the active component is presented. The proposed circuit configuration comprising two CFTAs, one grounded resistor and two grounded capacitors can simultaneously provide two explicit quadrature output currents and two quadrature output voltages. Moreover, the proposed circuit topology enjoys the advantage of independent control of the condition of oscillation and frequency of oscillation and good active and passive sensitivity performances. The functionality of the proposed quadrature oscillators has been verified by PSPICE simulations.

scholarly journals Study of off-axis current drive using EC top-launch in KSTAR

2019 ◽  
Vol 203 ◽  
pp. 02003
Author(s):  
Young-soon Bae
Keyword(s):  
Operation Research ◽  
Essential Element ◽  
Current Drive ◽  
Electron Trapping ◽  
Lower Hybrid ◽  
Low Density ◽  
Simulation Studies ◽  
High Current ◽  
High Efficient ◽  
Lower Hybrid Current Drive

The off-axis current drive using electron cyclotron (EC) wave is typically very low due to the low density and temperature and electron trapping effect when it is launched from outside midplane. However, the heating and current drive by EC wave is being regarded as a essential element as an off-axis current drive source together with lower hybrid current drive (LHCD) for advanced tokamak operation research in KSTAR in future. Therefore, the reliable and high efficient ECCD using top launch has been studied for two different launch schemes of down-shift and up-shift resonance with various EC frequencies which will be available in the future KSTAR ECRH system. The ray tracing (GENRAY) simulation studies show that a broad ECCD profile peaked off axis is obtained with a high current drive efficiency for both schemes. It is almost twice as high as that of the outside midplane launch for the fundamental O-mode EC wave.

High Current Drive in Ultra-Short Impact Ionization MOS (I-MOS) Devices

2006 ◽  
Author(s):  
C. Charbuillet ◽  
S. Monfray ◽  
E. Dubois ◽  
P. Bouillon ◽  
F. Judong ◽  
...  
Keyword(s):  
Impact Ionization ◽  
Current Drive ◽  
High Current ◽  
Mos Devices

Research on Current Control of Photovoltaic Grid-Connected Inverter

2013 ◽  
Vol 291-294 ◽  
pp. 2446-2451
Author(s):  
Yan Zhang ◽  
Wei Wang ◽  
Shi Tao Wang
Keyword(s):  
Phase Difference ◽  
Field Experiments ◽  
Current Control ◽  
Experimental Results ◽  
Current Frequency ◽  
Feed Forward ◽  
Grid Voltage ◽  
Feed Forward Control ◽  
Grid Connected Inverter

Grid-voltage feed-forward control was added to improve the grid-connected current quality on photovoltaic grid-connected inverter. The method decreases the phase difference between the grid-connected current and grid voltage and reduces the total harmonics distortion (THD) of grid-connected current. So the grid-voltage feed-forward compensation can improve grid-connected current availably and keep the current frequency and phase synchronous to the grid. The study is validated through simulations and field experiments. Experimental results obtained on 2.5-kw inverter demonstrate the feasibility of the proposed method.

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