• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.539-542
• /
• 1987

This paper presents driving circuits technology to enable high speed drive of MOSFET, IGBT(Insulated Gate Bipolar Transistor) and SIT(Static Induction Transistor). In addition to, it demonstrates application circuits(high frequency resonant type inverters, ultrasonic power supply etc.) using the, developing drive circuits.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.33 no.4
• /
• pp.134-139
• /
• 1984

This paper presents the computer program to design the synchronous sequential logic circuit. The computer program uses the MASK method to get the circuit of optimal cost. The computer program takes as an input, the minimal reduced state transition table where each state has its internal code. As an output,the optimal design of synchronous sequential logic circuit is generated for each flipflop type of JK,T,D, and RS respectively. And these circuits for 4 flipflop types are evaluated and sorted in ascending order of their costs, so that the user can select the proper flipflop type and its circuit. Furthermore,the proposed computer program may be applied to state assignment with its facility of cost evaluation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.4
• /
• pp.667-673
• /
• 2000

This paper presents the modeling method of nonlinear circuits with lumped elements by using a hybrid Haar -wavelet MRTD/FDTD techniques. To analyze nonlinear circuits with lumped elements, the Haar-wavelet MRTD scheme is applied to the entire structure of interest and the conventional FDTD scheme is locally used to describe the characteristics of the lumped elements. To validate the scheme, microstrip structure with lumped elements and a single diode mixer are simulated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.11a
• /
• pp.353-356
• /
• 1996

Ultra-high-speed analog and digital ICs (integrated circuits) fur 10Gbit/sec optical communication systems have been designed, fabricated and analyzed in this research. These circuits, which are laser diode (LD) driver, pre-amplifier, automatic gain controlled (AGC) amplifier, limiting amplifier and decision circuit, have been implemented with AIGaAs/GaAs heterojunction bipolar transistors (HBTs). The optimized AIGaAs/GaAs HBTs for the 10Gbps circuits in this work showed the cutoff and maximum oscillation frequencies of 65㎓ and 53㎓, respectively. It is demonstrated in this paper that the 10Gbps optical communication system can be realized with the ICs designed and fabricated using AlGaAs/GaAs HBTs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.11a
• /
• pp.86-88
• /
• 1996

A method is presented for the development of the PC-based measurement system on the 6 cathodes-single anode type multi-functional oxygen electrodes for detecting various components of the solution by measuring the dissolved oxygen(DO) concentration. The system is consisted with the 6 channel sensor signal modyfing circuits for the sensor and the PC interface circuits using the single chip microprocessor 80c196kc. Typical polarograms for the DO probes under test using this sensor circuits are presented. This system covers wide range of measuring time from 300sec to over 16 hour in one measurement step by programming the 9 monitor disply mode.

• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.49-51
• /
• 1994

LIM has been developed for use in the industry, transportation, OA, FA because of the merits of direct drive and simple structure. The thrust control of LIM usually has been the average thrust control. However, vector control is required to control the instantaneous thrust force for an accurate positioning and speed control. To obtain dynamic vector control characteristics, it is important to make equivalent circuits which represent exactly LIM In this paper, asymmetrical d-q equivalent circuits is built [1] and vector control characteristics is calculated by simulation using these circuits.

• Proceedings of the KIEE Conference
• /
• 2003.11b
• /
• pp.275-278
• /
• 2003

This paper presents a full-adder using current-mode multiple valued logic CMOS circuits. This paper compares propagation delay, power consumption, and PDP(Power Delay Product) compared with conventional circuit. This circuit is designed with a samsung 0.35um n-well 2-poly 3-metal CMOS technology. Designed circuits are simulated and verified by HSPICE. Proposed full-adder has 2.25 ns of propagation delay and 0.21 mW of power consumption.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.270-272
• /
• 2003

Switching power supplies are widely used in many industrial fields. Power factor correction(PFC) circuits have tendency to be applied in new power supply designs. The input active power factor correction(APFC) circuits can be implemented using either the two-stage approach or the single-stage approach. The single-stage PFC circuit has advantage to reduce the number of components by eliminating a need for the PFC switch and control circuit. However, unlike in the two-stage approach, the do voltage on the energy storage capacitor in a single-stage PFC circuit is not well regulated. As a result. in universal line application($90{\sim}265Vac$), the storage capacitor voltage varies with the load and line variation. In this paper, the performance of output voltage regulation and transient response are clarified here. The validity of designed boost PFC circuit is confirmed by MATLAB simulation and experimental results of 2 [kW] prototype converter.

• Journal of Aerospace System Engineering
• /
• v.8 no.1
• /
• pp.1-6
• /
• 2014

The conventional hydraulic circuits for electro-hydrostatic actuators equipped with a single-rod cylinder can oscillate under overrunning load conditions. In this paper the oscillation problem encountered in the conventional hydraulic circuits for EHAs is analyzed and it is shown by simulation results that this problem can be solved by employing a counter balance valve instead of a pilot-operated check valve generally used in the conventional hydraulic circuits.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.1724-1728
• /
• 2008

Track circuit is transmitted throughout the rails. In order to insure safe and reliable operation of track circuits, the track and the environment should respect mandatory electrical characteristics. In addition, for cab signalling through track Circuit as per TVM 430, these electrical characteristics should insure the transmission to the train. Track circuits have several operation and safety functions. They can detect the train position and broken rails. When track circuits are used as track to train transmission, they also have to be powered enough to be captured by the train sensors.