• Fire Protection Technology
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• s.12
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• pp.5-9
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• 1992

This reoprt is explained about test results of pressure operated switch for automatic fire extinguishing systems. It may include pressure operated Switch for automatic water supply control valves for use in automatic fire suppression system for fire protection service. The testing program was progressed devided by Two testing items, extermal oppearane test and performance test. The object of this report is present the problem which appear from the analysis of test results.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1256-1267
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• 2017

A fault tolerant structure and its corresponding control strategy for electromagnetic stirring power supplies are proposed in this paper. The topology structure of the electromagnetic stirring power supply contains two-stages. The fore-stage is the PWM rectifier. The back-stage is the fault tolerant inverter, which is a two-phase three-bridge orthogonal inverter circuit while operating normally. When the power switch devices in the inverter are faulty, the structure of the inverter is reconfigured. The two-phase half bridge inverter circuit is constructed with the remaining power switch devices and DC-link capacitors to keep the system operating after cutting the faulty power switch devices from the system. The corresponding control strategy is proposed to let the system work under both normal and fault conditions. The reliability of the system is improved and the requirement of the electromagnetic stirring process is met. Finally, simulation and experimental results verify the feasibility of the proposed fault tolerant structure and corresponding control strategy.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.391-396
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• 2009

In this paper, a control algorithm for DC-Link voltage unbalancing compensation of a four-switch inverter for a three-phase BLDC motor drive is proposed. Compared with a conventional six-switch inverter, the split source of the four-switch inverter can be obtained by splitting DC-link capacitor into two capacitors to drive the three phase BLDC motor. The voltages across each of two capacitors are not always equal in steady state because of the unbalance in the impedance of the DC-link capacitors $C_1$ and $C_2$ or the variable current flowed into the capacitor's neutral point in motor control. Despite the unbalance, if the BLDC motor may be run for a long time the voltage across one of the capacitors is more increased. So the unbalance in the capacitors voltages will be accelerated. As a result, The current ripple and torque ripple is increased due to the fluctuation of input current which flows into 3-phase BLDC motor. According to that, the vibration of motor will be increased and the whole system will be instable. This paper presents a control algorithm for DC-Link voltage unbalancing compensation. The sampling from the voltages across each of two capacitors is used to perform the voltage control of DC-Link by using the feedforward controller.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.136-144
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• 2010

This paper presents the two-switch interleaved active clamp forward converter, which is mainly composed of two active clamp forward converters. Only two switches are required, and each one is the auxiliary switch for the other. So, the circuit complexity and cost are reduced and control is more simple. An additional resonant inductance is employed to achieve ZVS(Zero-Voltage-Switching) during the dead times. Interleaved output inductor currents diminish the voltage and current ripple. Accordingly, the smaller output filter and capacitors lower the converter volume. This research proposed the Two-switch interleaved Active Clamp Forward Converter characteristic. The principle of operation, feature and design considerations is illustrated and the validity of verified through the experiment with a 160[W] based experimental circuit.

• Progress in Superconductivity and Cryogenics
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• v.13 no.1
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• pp.31-35
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• 2011

A Hybrid Fault Current Limiter(FCL) which has more advantages in fast response and thermal characteristics than a simple resistive FCL had been proposed by our group. The Hybrid FCL consists of a resistive FCL for the magnitude of the first peak of fault current, and a fast switch for detecting fault current and generating the repulsive force within a cycle in fault situation. In ideal case, the impedance of the fast switch wound with two other kinds of HTS tape is negligibly zero in normal operation. But, during the fault situation, each HTS tape has different quench characteristics because of asymmetric current distribution. And this phenomenon causes effective flux and this flux opens the switch through the repulsive force applied to a metal plate of the fast switch. The magnitude of the repulsive force affects the switching characteristics of the fast switch. It should be large enough to raise the metal plate up. Otherwise the arc re-out break which are caused by not enough repulsive force to raise the metal plate up can cause unintended operation of the fast switch. In this paper, the numerical calculation of the repulsive force applied to the metal plate of the fast switch in various combinations of HTS tapes was performed by using the short-circuit test and finite element method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1926-1940
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• 1998

This paper is the part II of research results on the performance evaluation of fully interconnected ATM switch, and includes the performance evaluation results for bursty traffic and nonuniform distribution. The switch model is a fyully interconnected switch type proposed by ETRI and is the proper architecutre for a small-sized switch element. The proposed switch consists of two steps of buffering scheme in the switch fabric in order to effectively absorb the effect of bursty nature of ATM traffic. The switch uses bit addressing method for addressing shcmeme and thus it is easy to implement multicasting function without adding additional functional block. In order to incorporate the bursty nature of traffic in ATM networks, we use IBP(Interrupted Bernoulli Process) model as an input traffic model as well as random traffic model which has been used as a traditional traffic model. In order to design the various scenarios for simulation, we considered both uniform and nonuniform output distribution, and also implemented multicast function. In this paper, we presented the simulation results in diverse environments and evaluated the performance of the switch.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.245-249
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• 2010

Now normally using a contact method of vehicle Inhibitor Switch that is use direct voltage level signal. This method is good solution for signal deliverly. but The contacted method have a short lifetime because of deterioration of contact surface. so we suggest to non-contacted method using magnetic sensor. The magnetic sensor is used to non-contacted method that is solution for problem of contacted method. In this paper using that of magnetic sensor feature, so we applied to Vehicle Transmitter switch that of non-contacting method. Sensor voltage outputs have variable electric potential that normally 0 mV to 150 mV, and it is depend on Switch Angle. we used two differential sin wave for switching of 5 state signal.

• ETRI Journal
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• v.31 no.6
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• pp.770-777
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• 2009

We have developed a fully functional reconfigurable optical add-drop multiplexer (ROADM) switch module using a polymer integrated photonic lightwave circuit technology. The polymer variable optical attenuator (VOA) array and digital optical switch array are integrated into one polymer PLC chip and packaged to form a 10-channel VOA integrated optical switch module. Four of these optical switch modules are used in the ROADM switch module to execute 40-channel switching and power equalization. As a wavelength division multiplexer (WDM) filter device, two C-band 40-channel athermal arrayed waveguide grating WDMs are used in the ROADM module. Optical power monitoring of each channel is carried out using a 5% tap PD. A controller and firmware having the functions of a 40-channel switch and VOA control, optical power monitoring, as well as TEC temperature control, and data communication interfaces are also developed in this study.

• Journal of Microbiology
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• v.37 no.3
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• pp.180-184
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• 1999

hybridoma cells producing IgM anti-pneuococcal 6B polysaccharide antibodies were induced to switch to IgG-producing cells in vitro by treating with acridine orange. Treating 0.5 $\mu\textrm{g}$/ml of acridine orange for 24 hours generated maximal number of variant cells. The maximal isotype switch frequency was 3${\times}$10-5, which is about 30-fold higher than the frequency of spontaneous switching. Resulting IgG-producing variants were enriched by sib selection and ELISA spot assay. Two IgG3-producing variant cells were finally cloned by limiting dilution. The variant cells produced similar amounts of antibodies as their parental cells did. The two switched antibodies had similar reactivity to pneumococcal 6B polysaccharide. When compared to their parental IgM antibodies, the switched IgG3 than that of IgM antibody. The antibodies will be useful as essential tools for comparative study of the role of heavy chain isotypes in protection against Streptococcus pneumoniae.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.884-887
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• 2002

This paper considers a scheduling problem of routers with VOQ(Virtual Output Queue)s, where the router has an N ${\times}$N port input-queued switch and each input queue is composed of N VOQs. The objective of the paper is to develope scheduling algorithms which minimize mean tardiness under a common due date. The paper characterizes the optimal solution properties. Based upon the characterization, a integer programming is formulated for the optimal solution and two optimal solution algorithms are developed for two special cases of 2 ${\times}$2 switch and N${\times}$N switch with identical traffic.