• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.643-648
• /
• 2005

Headlight monitoring is one of the new requirement in the modern Metro EMU design. In order to meet this requirement. several kinds methods are already provided in the train. This paper introduces another method. which is designed with the darlington circuit and can switch off/on the headlight with the circuit. Following the conceptual method. the monitoring module was developed and installed in domestic line. Investigation of the concept shall be focused on the more smaller module and expending the module to other part.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1537-1539
• /
• 2004

This paper introduces a supplementary module reducing the standby-power of Power Line Communication(PLC) modem, one of the network equipments that take up much of the stand-by power. This supplementary module consists of three parts, such as a compare part, a control part, and a switch part. This supplementary module controls the power going from the power supply element into PLC modem, which brings about the effect of standby-power reduction. It is assured that over $30\%$ standby-power reduction is estimated when we applied this module to a low-speedy PLC control modem.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.296-299
• /
• 2004

This paper introduces a supplementary module reducing tile standby-power of Power Line Communication(PLC) modem, one of the network equipments that take up much of tile stand-by power. This supplementary module consists of three parts, such as a compare part, a control part, and a switch part. This supplementary module controls the power going from the power supply element into PLC modem, which brings about the effect of standby-power reduction. It is assured that over 30% standby-power reduction is estimated when we applied this module to a low-speedy PLC control modem.

• Journal of Power Electronics
• /
• v.16 no.2
• /
• pp.490-497
• /
• 2016

The analysis of the switch status of each unit module of a cascaded multi-level inverter reveals that the working condition of the switch of a chopper arm causes unnecessary switching under the conventional unipolar sinusoidal pulse width modulation (SPWM). With an increase in the number of cascaded multilevel inverters, the superposition of unnecessary switching gradually occurs. In this work, we propose an improved SPWM strategy to reduce switching in cascaded multilevel inverters. Specifically, we analyze the switch state of the switch tube of a chopper arm of an H-bridge unit. The redundant switch is then removed, thereby reducing the switching frequency. Unlike the conventional unipolar SPWM technique, the improved SPWM method greatly reduces switching without altering the output quality of inverters. The conventional unipolar SPWM technique and the proposed method are applied to a five-level inverter. Simulation results show the superiority of the proposed strategy. Finally, a prototype is built in the laboratory. Experimental results verify the correctness of the proposed modulation strategy.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.2067-2069
• /
• 1998

A prototype semiconductor switch for the command resonant charging system has been developed for a line type modulator, which charges parallel pulse forming network(PFN) up to voltage of 5 kV at repetition rates of 60 Hz. A phase controlled power supply provides charging of the 4.7 ${\mu}s$ filter capacitor bank to voltage up to 5 kV. A solid state module of series stack array of sixe matched SCRs(1.6 kV, 50 A) is used as a command charging switch to initiate the resonant charging cycle. Both resistive and RC snubber network are used across each stage of the switch assembly in order to ensure proper voltage division during both steady state and transient condition. A master trigger signal is generated to trigger circuits which are transmitted through pulse transformer to each of the 6 series switch stages. A pulse transformer is required for high voltage trigger or power isolation. This paper will discuss trigger method, protection scheme, circuit simulation, and test result.

• Proceedings of the KIPE Conference
• /
• 1997.07a
• /
• pp.276-279
• /
• 1997

본 논문은 통신용전원장치와 같은 대용량의 DC 전원 장치에 적용하기 위하여 3상용 6 Switch로 구성된 Bridge로써 대용량 DC-DC converter에 적합한 Topology에 관한 것이다. 기본 동작은 기존의 Phase shifted ZVS PWM 방식을 사용하며, Bridge의 바깥쪽 양쪽암의 펄스폭을 제어하는데, 같은 펄스를 동시에 주는 방식과 각각 별도로 제어하는 방식, 두암의 위상을 지연시키는 방식에 관하여 연구하였다. 제안된 Topology들은 컴퓨터 시뮬레이션을 수행하여 그 동작특성을 확인하였고, 대용량에 적용할 수 있음을 확인하였다. 장치의 용량은 출력 500[A]/30[V] 회로를 구성하여 각각의 경우에 대하여 컴퓨터 시뮬레이션 결과를 제시하였다.

• Journal of the Optical Society of Korea
• /
• v.11 no.4
• /
• pp.145-148
• /
• 2007

In this paper, we discuss a study on Advanced TCA(ATCA) based 40 Gbps level Optical transport platform having 120 Gbps(12, 10 Gbps modules) switching capacity as an OTP based large capacity multi service technology. The ATCA-based OTP(Optical Transport Platform) is composed of OTH(Optical Transport Hierarchy) 10 or 40 Gbps client signal interface module, OTH 10 Gbps transport module, high-rate OTH unit switch, system processor, and can be installed in ATCA platform.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.73-74
• /
• 2016

This paper proposes a wide output range AC/DC converter for a rechargeable battery of electric vehicle. In the proposed wide output range AC/DC converter for rechargeable battery of electric vehicle, the main transformer in the DC/DC stage is divided by two. Therefore, if the switch is connected to the middle tap, then half of the maximum voltage is applied. Otherwise, it can be applied the full range of the high voltage by connecting the switch to the whole tab. And also, it is designed to have a wide output voltage range by applying Vin/2 made by changing the full-bridge to half-bridge by using the bridge change switch of the input stage. As it can be supplied the wide range output voltage with a single module, it has the advantage of space utilization and cost reduction effect.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.113-116
• /
• 1999

This paper presents a hardware architecture of AAL(ATM Adaptation Layer) type 2 switch. The proposed architecture can assign and configure maximum AAL2 CID limit. AAL2 is the protocol which has been recommended by ITU-T and ATM-Forum for low bit rate delay sensitive services. The architecture assumes 155 Mbps STM-1/STS-3c physical interface, maximum VCC can be 64K connections. It can support maximum 16,384M AAL2 connections. For efficient use of peripheral memory, a concept of segment address was proposed. The proposed AAL2 switch hardware architecture can be used in ATM network as a standalone server or embedded module in a ATM switching system.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.4
• /
• pp.142-151
• /
• 1996

This paper presents a new symmetrical routing architecture for FPGA and an efficient routing algorithm for the architecture. The routing architecture adopts the segmented wires and the improved switch modules. Segmetned wires construct routing channels which pass through the chip in vertical and horizontal directions. To maximize the utility of a track, a track in each switch module can be separated in two part using a programmable switch to route two different net. The proposed routing algorithm finds all assignable tracks for a given net and selects the best track from assignable tracks to minimize the number of programmable switches and the unused portion of the wire segments. In order to stabilize the perfomrance of the algorithm, the routing order is defined by weighted sum of the number of wire segment, the length of wire segmetn, and the number of pin. Experimental results show that routability is improved dramatically and the number of crossing switches are reduced about 40% compared with the previous works.