• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1345-1347
• /
• 2008

This paper described a method of determining whether arcing is present in a low-voltage wiring system. We simulated the series arcing that generated in electrical loads and fabricated a arc detection module which can discriminate between normal and arcing state. The module consists of a high-pass filter with a low cut-off frequency of 3 kHz to attenuate power frequency voltage and an active band-pass filter with a frequency of 4 kHz ${\sim}$ 8 kHz to detect series arc signals only. We tested an Incandescent lamp that was controlled by a dimmer and analysed. The module consists of a high-pass filter with a low cut-off frequency of 3 kHz to attenuate power frequency voltage by 80 dB and an active band-pass filter with a frequency of 4 kHz to detect series arc signals only. From the experimental results, we could detect series arc signals without an influence of non-linear loads.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.4
• /
• pp.886-893
• /
• 2004

In this paper, active resonator oscillator using active band pass filter with gain, active resonator with negative resistance using transistor(agilent ATF-34143) is designed and fabricated. Proposed active resonator oscillator for local oscillator in ISM band(5.8GHz) is designed with 5.5 GHz oscillation frequency. Designed active resonator oscillator implemented on the substrate which has the relative dielectric constant of 3.38, the height of 0.508mm, and metal thickness of 0.018mm. Active resonator oscillators using active band pass filter with gain show the oscillation frequency of 5.6GHz with the output power of -2dBm and phase noise of -81dBc/Hz at the offset frequency of 100kHz. Active resonator oscillators active resonator with negative resistance show the oscillation frequency of 5.6, 5.8GHz with the output power of -4dBm and phase noise of -91dBc/Hz at the offset frequency of 100kHz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.353-354
• /
• 2014

An active vibration control technique of a time-varying cantilever beam is proposed in this study. A simple in-house coil sensor instead of expensive commercial sensors was used to measure the vibrational displacement of the beam. Active band pass filters and artificial neutral net works detect the frequencies, amplitudes, and phases of the main vibration mode. The time constants of the low pass filter representing the positive position feedback controller are updated in real-time, which generates the control voltage input to actuate the piezoelectric actuator and suppress the vibration. An experiment was successfully performed to verify the algorithm for a cantilever beam, which fundamental natural frequency arbitrarily varies between 9 Hz ~ 18 Hz. The present active vibration suppression technique can be applied to variety of structures which undergoes large variation of dynamic characteristics while operating.

• Proceedings of the IEEK Conference
• /
• 2003.07c
• /
• pp.2733-2736
• /
• 2003

This paper proposes a dry-type active surface EMG electrode for the myoelectric prosthetic hand. The designed electrode is small size for embedding in the socket of prosthetic hand, and it has three leads including the reference of signal. To acquire EMG signal rejected the power noise, a precision differential amplifier and various filters such as the band pass filter band rejection filter, low pass and high pass filter are embedded on the electrode. The final output of the electrode is integrated absolute EMG (IEMG) obtained by full rectifier and moving average circuits. From experimental results using the implemented dry-type active surface EMG electrode, the proposed electrode is feasible for the myoelectric prosthetic hand.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.8 no.5
• /
• pp.20-26
• /
• 1971

A function relationship between the envlope rise time and Q v91ue of band pass filter is studied by using the time response to the step and sinusodal inputs. It is discovered that the above relationship is linear in the very low frequency band. The filter was constructed by the Analog computer so as to do the function of 2nd order RC active band pass.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.10
• /
• pp.2395-2402
• /
• 2013

An active-RC channel selection filter (CSF) with the bandwidth of 40MHz and the improved linearity is proposed in this paper. The proposed CSF is the fifth butterworth filter which consists of a first order low pass filter, two second order low pass filters of a biquad architecture, and DC feedback circuit for cancellation of DC offset. To improve the linearity of the CSF, a body node of a MOSFET for a switch is connected to its source node. The bandwidth of the designed CSF is selected to be 10MHz, 20MHz and 40MHz and its voltage gain is controlled by 6 dB from 0 dB to 24 dB. The proposed CSF is designed by using 40nm 1-poly 8-metal CMOS process with a 1.2V. When the designed CSF operates at the bandwidth of 40 MHz and voltage gain of 0 dB, the simulation results of OIP3, in-band ripple, and IRN are 31.33dBm, 1.046dB, and 39.81nV/sqrt(Hz), respectively. The power consumption and layout area are $450{\times}210{\mu}m^2$ and 6.71mW.

• Smart Structures and Systems
• /
• v.22 no.1
• /
• pp.95-103
• /
• 2018

Active vibration control via inertial mass actuators has been shown as an effective tool to significantly reduce human-induced vertical vibrations, allowing structures to satisfy vibration serviceability limits. However, a lot of practical obstacles have to be solved before experimental implementations. This has motivated simple control techniques, such as direct velocity feedback control (DVFC), which is implemented in practice by integrating the signal of an accelerometer with a band-pass filter working as a lossy integrator. This work provides practical guidelines for the tuning of DVFC considering the damping performance, inertial mass actuator limitations, such as stroke and force saturation, as well as the stability margins of the closed-loop system. Experimental results on a full scale steel-concrete composite structure (behaves similar to a footbridge) with adjustable span are reported to illustrate the main conclusions of this work.

• Journal of Power Electronics
• /
• v.8 no.1
• /
• pp.91-100
• /
• 2008

The d-q harmonic detecting algorithms are dominant methods to generate current references for active power filters (APF). They are often implemented in the synchronous frame and time domain. This paper researches the frequency characteristics of d-q synchronous transformations, which are closely related to the analysis and design issues of control system. Intuitively, the synchronous transformation is explained with amplitude modulation (AM) in this paper. Then, the synchronous filter is proven to be a time-invariant and linear system, and its transfer function matrix is derived in the stationary frames. These frequency-domain models imply that the synchronous transformation has an equivalent effect of frequency transformation. It is because of this feature, the d-q method achieves band-pass characteristics with the low pass filters in the synchronous frame at run time. To simplify these analytical models, an instantaneous positive-negative sequence frame is proposed as expansion of traditional symmetrical components theory. Furthermore, the synchronous filter is compared with the traditional bind-pass filters based on these frequency-domain analytical models. The d-q harmonic detection methods are also improved to eliminate the inherent coupling effect of synchronous transformation. Typical examples are given to verify previous analysis and comparison. Simulation and experimental results are also provided for verification.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1972-1974
• /
• 2004

This paper describes the high pass filter with notch charecteristics. The proposed circuits configuration consists of two uniformly distributed RC line (herein after is called URC) and two gain amplifiers ($K_1$ and $K_2$). With the appropriate $K_1$ and $K_2$ , the circuit has a steeper slope of magnitude response at pass band steeper than using a single gain amplifier.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.4
• /
• pp.312-319
• /
• 2014

When distributed generation such as a wind power system is connected to the grid, it should meet grid requirements like IEEE Std. 1547, which regulates the anti-islanding method. Since the islanding may cause damage on electrical equipments or safety hazards for utility line worker, a distributed generation should detect it as soon as possible. This paper proposes a hybrid anti-islanding method coupled with the active and passive detection methods. To enhance the harmonic extraction capability for an active harmonic injection method, cascaded second-order band-pass filter and signal processing scheme are employed. Simulation and experiments are carried out under the islanding test condition specified in IEEE Std. 1547. Passive over/under voltage and over/under frequency methods are combined with the active method to improve the detection speed under certain condition. The simulation and experimental results are presented to verify that the proposed hybrid anti-islanding method can effectively detect the islanding.