• Proceedings of the KIPE Conference
• /
• 2003.11a
• /
• pp.132-136
• /
• 2003

Generally, PM BLDC drive system is necessary that the three Hall-ICs evenly be distributed around the stator circumference and encoder be installed in case of the 3 phase motor. So, the Hall-ICs are set up in this motor to detect the main flux from the rotor, and the output signal from Hall-ICs is used to drive a power transistor to control the winding current. However, instead of using three Hall-ICs and encoder, we used only two Hall-ICs for the permanent magnet rotor position and for the speed feedback signals, and also for a micro controller of 16-bit type (80C196KC) with the 3 phase PM BLDC whose six stator and two rotor designed. Two Hall-IC Hc and $H_B$ are placed on the endplate at 120 degree intervals, and with these elements, we estimated information of the others phase in sequence through a rotating rotor.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.5
• /
• pp.165-170
• /
• 2001

In the continuos process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, winding, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction play major role in the determination of the traction force between the moving web and the rollers. In this paper the characteristics of friction between the moving web and the rollers are studied. A procedure to determine the friction coefficient between the moving web and rollers is developed. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operation web tension increase.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.5
• /
• pp.52-59
• /
• 2014

This paper presents an improved operating characteristics of squirrel-cage induction motor(IM) for 5-phase 1.5kW, 220V, 60Hz in order to study a polyphase AC machinery that keep hold of advantages more than traditional three-phase a IM, such as reducing a amplitude of torque pulsation, decreasing electric noises, and increasing the reliability. The developed manufacturing motor was necessary to do improvement of speed regulation, efficiency, operating characteristics, and so on at rated load. There are remake a redesigned and distributed stator winding connection without changing the frames of stator and rotor core in previous established the motor by a repeat tests. There are shown a experiments results of no-load test, locked rotor test, operating characteristics at variable load, FFT analysis of harmonics within output voltages and current waveform, decided motor parameters.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.9
• /
• pp.53-61
• /
• 2013

This paper propose a improved operating characteristics of the 5-phase 5kW within developed the surface permanent mount synchronous generator (SPMSG) in order to make a study of a polyphase ac motors keeping hold of more advantages. The developed manufacturing motor was necessary to do improvement of voltage regulation, efficiency, operating characteristics, and so on at the rated load. There are remake a redesigned and distributed stator winding connection without changing the frames of stator and rotor core in previous established generator by a repeat tests. There are shown a amplitude and waveform of the generated electromotive force, FFT analysis of harmonics within output voltages, and reviewing a experiment results in load of resistive and 5-phase induction motor by variable generator output frequency.

• Journal of Conservation Science
• /
• v.31 no.3
• /
• pp.255-265
• /
• 2015

In this study, the potash glass beads of 281 samples in 30 sites analyzed until now were classified according to the chemical composition. And the color, size, manufacturing technique and distribution period were compared. Korea potash glass beads are divided into 3 types depending on the stabilizer content. I, II type is the CaO and $Al_2O_3$ content of less than 5%. Relatively, I type has a high CaO and II type has a high $Al_2O_3$. In contrast, III type comprises more than CaO 5%. I, II type is the saltpetre, III type is estimated using plant ash as row material of flux. A review of the properties by type, I type is cobalt blue, copper blue and purple beads. The outer diameter is sized to the range 1.4~7.4mm. Also it was produced by the drawing technique. It was used continuously from BC 1C until around AD 6C. On the other hand, II type is outer diameter of 1.9~3.6mm and a copper blue beads. manufacturing technique is the same as the I type. This seems to have been in use since around AD 1C to 4C. Finally, III type is brown, colorless, amber beads and an outer diameter of about 10mm. It was formed by winding technique and appeared in the tombs of Goryeo and Joseon Dynasty. As a result, 3 types of potash glass beads distributed in Korea is likely to flowing through the various trade routes from different provenances.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.6
• /
• pp.536-543
• /
• 2004

Slotless Permanent Magnet Brushless DC Motor(PM BLDC) with the characteristics of high speed and power density has been more widely used In Industrial and factory machine. Generally, PM BLDC meter is necessary that the three Hall-lCs evenly be distributed around the stator circumference in case of the 3 phase motor. The Hall-ICs are set up in PM BLDC Motor to detect the main flux from the rotor. therefore the output signal from Hall-ICs is used to drive a power transistor to control the stator winding current. However, instead of using three Hall-ICs, if it used only one Hall-IC, we can estimate information of the others phase in sequence through a rotor This paper identified the characteristics and performance by using one Hall-IC with the 3-phase, 2-pole, 6-slot PM BLDC motor.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1297-1300
• /
• 2008

A conventional linear accelerator system requires a flat-topped pulse with less than ${\pm}$ 0.5% ripple to meet the beam energy spread requirements and to improve pulse efficiency of RF systems. A pulse transformer is one of main determinants on the output pulse voltage shape. The pulse transformer was investigated and analyzed with the pulse response characteristics using a simplified equivalent circuit model. The damping factor ${\sigma}$ must be >0.86 to limit the overshoot to less than 0.5% during the flat-top phase. The low leakage inductance and distributed capacitance are often limiting factors to obtain a fast rise time. These parameters are largely controlled by the physical geometry and winding configuration of the transformer. A rise time can be improved by reducing the number of turns, but it produces larger pulse droop and requires a larger core size. By tradeoffs among these parameters, the high-voltage pulse transformer with a pulse width of 10 ${\mu}s$, a rise time of 0.84 ${\mu}s$, and a pulse droop of 2.9% has been designed and fabricated to drive a klystron which has an output voltage of 284 kV, 30-MW peak and 60-kW average RF output power. This paper describes design optimization of a high-voltage pulse transformer for high-power pulsed applications. The experimental results were analyzed and compared with the design. The design and optimal tuning parameter of the system was identified using the model simulation.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.4
• /
• pp.311-318
• /
• 2004

Generally, PM BLDC drive system is necessary that the three Hall-ICs evenly be distributed around the stator circumference and encoder installed in case of the 3 phase motor. The Hall-ICs are set up in this motor to detect the main flux from the rotor. So the output signal from Hall-ICs is used to drive a power transistor to control the stator winding current. Instead of using three Hall-ICs and encoder, this paper uses only two Hall-ICs for the permanent magnet rotor position and for the speed feedback signals, and uses a micro controller of 16-bit type(80C196KC) with the 3 phase PM BLDC whose six stator and two rotor designed. Two Hall-IC Hc and $H_B$ are placed on the endplate at 120 degree phase difference. With these elements, we estimate information of the other phase in sequence through a rotating rotor.

• Cartoon and Animation Studies
• /
• s.28
• /
• pp.55-78
• /
• 2012

Underground comics is a trend of comics started by reflecting hippie culture in the 1960's. It reflects hippie culture proclaiming return to nature and denying war with no humanity and social systems of material civilization expresses anti-culture in a radical and humorous way. Robert Crumb adds the features of hippie culture to comics aggressively with issuing comic book, series. Especially received great response from hippie. It became the chance for underground comics to improve further. includes works like 'Whiteman' expressing the hidden desire of conservative middle class or 'Keep on truckin' describing youths in hippie culture as characters lording it over somebody, strutting confidently across various landscape. The Comic was published and distributed independently and character-driven comic that reflected the variety of hippie culture. The Comic represented the characteristics of the underground comics very well. Winding lines and points, a strong contrast, were used for excellent graphical effect. These comics escaped from heroic comics of the era and played great roles in opening an era of underground comics which express satires of social culture more freely.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.11
• /
• pp.1675-1680
• /
• 2013

Recently, the permanent magnet linear synchronous motor as low noise, high speed and high thrust force transportation system has been proposed but this motor causes an increase of material cost because of its characteristic arranging the armature on the full length of transportation lines when this system is applied to the long distance transportation system. Therefore, we suggested discontinuous arrangement method of the armature to solve this problem. However, Detent force which causes thrust force ripple generating noise, vibration and decline of performance is generated when a mover pass between the armatures. Thus, in this paper, we examined characteristic of detent force to reduce the end edge effect according to the end edge teeth's height and auxiliary teeth and suggested the shape that can the most reduce the detent force.