• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.9 no.3
• /
• pp.80-87
• /
• 1995

In this paper, we design the microcontroller-based optimal lead angle control system on the basis of the presented maximum average torque formula of the permanent-type stepping motor with respect to the inductance. We confirm that optimal lead angle enlarges the operating range twice as much and increases the torque over all of the operating range in the case of presented formula as well as experimental results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.651-652
• /
• 2012

Wireless monitoring and hybrid mobile web have become an emerging area of research in recent year. This paper deals with the design and implementation of mobile web page for sensing data monitoring. The mobile web monitoring system for sensing data transmission is implemented by 8-bit AVR microcontroller and bluetooth communication module.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.316-319
• /
• 1998

RPWM(Random Pulse Width Modulation) is a switching technique to spread the voltage and current harmonics on the wide frequency area. Using randomly changed switching frequency of the inverter, the power spectrum of the electromagnetic acoustic noise cab be spread to the wide-band area. The wide-band noise is much more comfortable and less annoying than the narrow-band one. So RPWM have been attracting an interest as an excellent method for the reduction of acoustic noise on the inverter drive system. In this paper a new RPPWM (Random Position PWM) is proposed and implemented. Each of three pulses is located randomly in each switching interval. Along with the randomization of PWM pulses, the space vector modulation is executed in the C167 microcontroller also. The experimental results show that the voltage and current harmonics were spread to wide band area and that the audible switching noise was reduced by proposed RPPWM method.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.321-324
• /
• 1998

A single phase induction motor (SPIM) rated in fractional horsepower is widely used in home and industrial equipment: washing machines, fans, refrigerators, etc. In this paper, authors present the experimental results of the SPIM under controlling of currents of main and auxiliary windings by using a one-chip micro stator(OMS). This new starting method is developed to replace the conventional starting device consisted with a mechanical switch and a capacitor. In mentioned method, the soft-starting of SPIM is simply implemented and higher efficiency is obtained in comparison with conventional condenser type SPIM.

• Journal of Electrical Engineering and Technology
• /
• v.5 no.4
• /
• pp.623-630
• /
• 2010

This paper presents the implementation and characteristic analysis of a drive system for a three-phase permanent magnet motor with independent excitation winding that is applicable for electric bicycles. The design features improves the phase current waveform, output power, and torque by using advance angle control. This adjusts the phase angle of each phase current in relation to back EMF. In addition, a DC-side PI current control is performed through PWM generation circuit using a low-cost one-chip microcontroller and a CPLD chip, resulting in reduced system costs. Finally, the validity of this control scheme for driving electric bicycles and output/torque improvement characteristics are verified through analysis and experimental results.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.1
• /
• pp.205-213
• /
• 2014

A wind generator (WG) maximum power point tracking (MPPT) system is presented here. It comprises of a variable-speed wind generator, a high-efficiency boost-type dc/dc converter and a control unit. The advantages of the aimed system are that it does not call for the knowledge of the wind speed or the optimal power characteristics and that it operates at a variable speed, thus providing high efficiency. The WG operates at variable speed and thus suffers lower stress on the shafts and gears compared to constant-speed systems. It results in a better exploitation of the available wind energy, especially in the low wind-speed range of 2.5-4.5 m/s. It does not depend on the WG wind and rotor-speed ratings or the dc/dc converter power rating. Higher reliability, lower complexity and cost, and less mechanical stress of the WG. It can be applied to battery-charging applications.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06b
• /
• pp.447-449
• /
• 2012

This paper present an intelligent microcontroller based chess playing robot which can play a board game against opponent and calculate its moves in a non-idealized environment. In this work, for the sake of simplicity task is accomplished by using Cartesian coordinate system. Chess playing system has been designed in such a way that it provides an interface between user and robot to control chess movements using RS232. Various algorithms are implemented for interfacing hardware in C++ language. Our main goal is to design a cost effective and highly accurate robot system that consumes minimal power to complete its task.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1730-1732
• /
• 2002

This paper proposes a multi-color lamp using ROB LEDs for color variation. The lamp has an internal controller circuit. so it can be directly connected to the existing incandescent lamp socket. It's main body is comprised of two PCB layers. The upper layer contains 44 LEDs and the lower one has a simple microcontroller-based PWM control circuit. Appropriate number of RGB LEDs are so chosen according to the color mixing theory that the overall LEDs represent a color temperature of 6500K. The lamp has functions of both ON/OFF control and PWM control, so is capable of color variation of over 100,000 colors and of more than 10 patterns.

• Proceedings of the Korea Contents Association Conference
• /
• 2017.05a
• /
• pp.439-440
• /
• 2017

최근 다양한 분야에서 IoT(Internet of Things)를 위한 마이크로 컨트롤러 디바이스가 사용되고 있다. BLE 통신을 통한 전력소모감소로 인해 작은 크기에서 다양한 기능을 수행할 수 있게 되었으며, 이를 위해 마이크로 컨트롤러에서 RTOS가 사용되는 분야가 늘어나고 있다. 본 연구에서는 국내 기술로 개발된 iRTOS를 IoT 디바이스에 포팅하는 연구를 수행한다. Cortex-M 시리즈를 위해 내부 컨텍스트 관리 및 RTOS 타이머 관련 내용을 수정하여 포팅하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.472-472
• /
• 2000

An analog signal conditioner using fuzzy logic technique, which has multiple-input and multiple-output terminals, is proposed in this paper. The proposed signal conditioner can be employed to linearly translate the level of signals to a standard voltage signal (1-5V) and convert the form of signals to a standard current signal (4-20mA). The implementation method based on the use of a commercial 8-bit microcontroller, the analog-to-digital (A/D) converters, the digital-to-analog (D/A) converters and the voltage-to-current (V/I) converter. The simulation result and the experimental results are presented, which further confirm the feasibility of this approach.