• 전기의세계
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• v.28 no.9
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• pp.51-59
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• 1979

The forming and design method of D.C thyristor chopper circuit for DC Series motor control is suggested, ard the computation method of thyristor commutaing element's, value which makes it all the more important, is possible. Also the trigger circuit was dealt with. In this paper, in order to control the duty cycle, the duty time is kept on constancy and variable chopping frequency was adopted. By above mentioned circuit design method, the D.C thyristor chopper circuit was implemented and tested. In this circuit, the result of D.C motor control was good and reliable. The relation between the $K_{d}$ and the ratio of input-output current, or the characteristic of speed was varied lineary at the range 0.1 ~ 0.9 of duty cycle. This confirms the fact that D.C to D.C power conversion which is the merit of chopper control is operated most likely a transformer.ormer.

• Journal of Practical Engineering Education
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• v.9 no.2
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• pp.99-106
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• 2017

The most important thing in STEAM education is to enhance students' interest and understanding of science and technology. In this paper, we propose basic circuit system design and control method applicable to STEAM fusion education. The circuit system design practice using the breadboard is designated as an essential curriculum in the corresponding department at the high school and college level in the domestic curriculum. However, there is a lack of STEAM convergence implementation examples that can easily understand circuit system design and control methods. Therefore, we proposed and tested a method to implement and control a media art type circuit system.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.5
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• pp.71-85
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• 1993

The Cycloconverter that the author is going to treat in this paper, has strong advantages over the D.C. Link Inverter in points of chattering torque problem and natural commutation. Thus, the Cycloconverter is expected to be well applied to large and low-speed machines which require better speed control at low frequency. But the control circuit of Cycloconverter has two weak points described as follows. 1) Because of its rather complicated control circuit, it is likely to be illoperating due to unexpected noise signals, thus the higher the accuracy and reliability of the circuit is required to be, the more the circuit may cost. 2) Because the load current is not purely sinusoidal, the Cycloconverter may possibly be destroyed in case of inaccurate convert switching resulted from the difficulties in detecting the load current-zero and the current direction at the moment. In this paper, the author first of all intends to design and build a modified VVVF-type Noncirculating Current Cycloconverter to which recently proposed control methods are applied for improving the circuit simplicity, the control performance, and the system reliability. And then, experiments for observing the output waveforms of the Cycloconverter which is controlled by Singled-Board Computer using 8086 16-bit microprocesser are carried out. Finally the author concludes the result of this study as follows. 1) By replacing the conventional analog control circuits such as Reference Wave Generator, Cosine Timing Wave Generator, and Comparator with softwares, a great circuit simplicity is achieved. 2) The output of the designed Cycloconverter changes its frequency very fast without showing discontinuity of its waveform, and this waveform characteristics enables the smooth speed control of Induction Motor. 3) The design control circuit of Cycloconverter can be applied to the systems of 12 or 24 pulses because of its short processing period.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.404-412
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• 2014

We proposed a design method for squib current supply & interlock circuits in guided-missile fire control systems. In order to design squib current supply circuits, various missile squib loads including line resistance and squib devices have to be considered in advance minimizing probability of redesign of circuits and reducing the development cost by implementing the most proper squib current supply circuit. Also, we presented a hardware interlock logic instead of the commonly used software safety logic to improve the safety of guided-missile fire control systems. The proposed squib interlock circuit enhances safety requirements of guided-missile fire control systems. We confirmed that simulation and measurement results of the proposed design method are the same as theoretical analysis results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.407-409
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• 2006

This paper presents the methods of designing the control circuits for a Class D amplifier to have a peak performance. The proposed approach is based on the three functional components - a carrier generator, a feedback circuit and a dead-time circuit. First the analog signal is applied to the controller, which outputs the 3 level PWM waveform. The controller used for this experiment is made of the operational amplifier and the logic circuit. The experimental results show that the control circuit performs with satisfaction and its output is proportional to input audio signal, providing a satisfactory 3 level PWM pattern. From this design methodology, by implementing a proposed control circuit we can achieve the efficient Class D amplifier using the half-bridge, full-bridge or push-pull topology at the output stage.

• Journal of Power Electronics
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• v.7 no.4
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• pp.294-300
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• 2007

This paper deals with a design of a bootstrap power supply using snubber energy regeneration, which is used to power a high-side gate driver of a half-bridge circuit. In the proposed circuit, the energy stored in the low-side snubber capacitor is transferred to the high-side bootstrap capacitor without any magnetic components. Thus, the power dissipation in the RCD snubber can be effectively reduced. The operation principle and design method of the proposed circuit are presented. The experimental results are also provided to show the validity of the proposed circuit.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.27-29
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• 2004

In this paper, a levitation control circuit for a magnetic levitation system supplied with a battery is designed. The control circuit consists of DSP, 4-quadrant chopper, and gap sensor as feedback sensors. Moreover the DSP includes PWM generator, A/D converter, etc. The feedback signals from gap sensors go into A/D converter of DSP to compare with reference. As a result, The design procedures of the levitation control circuit and battery power distribution system are described and basic experiment results are shown.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.434-438
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• 2000

In this paper the low cost sensorless control circuit for a PM synchronous motor without the mechanical rotor position sensors is presented. The sensorless control algorithm and position detection circuit for the sinusoidal current wave drive is more complex than that of the rectangular current wave drive. The proposed position sensing circuit is composed of an operational amplifier and several passive elements. The design procedures for getting the optimal parameters for the position sensing circuit are presented. The performance of the proposed algorithm is verified through the simulations and experiments.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.1
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• pp.8-15
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• 1993

A concrete disign of memory circuit is presented aiming at the application of sliding diagonal test patterns. A modification of sliding diagonal test pattern includes the complexity reduction from O(n$^{32}$) to O(n) using parallel test memory concept. The control circuit design was based on delay-element, and verified via logic and circuit simulation. Area overhead was evaluated based on physical layout using a 0.7 micron design rule resulting in about 1% area increase for a typical 16Mbit DRAM.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.2
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• pp.141-146
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• 2009

In this paper, a novel harmonic control circuit has been proposed for the design of high-efficiency power amplifier with Si LDMOSFET. The proposed harmonic control circuit haying the short impedances for the second- and third-harmonic components has been used to design the in/output matching network. The efficiency enhancement effect of the proposed harmonic control circuit is superior to the class-F or inverse class-F harmonic control circuit. Also, when the proposed harmonic control circuit has been adapted to the input matching network as well as the output matching network, the of ficiency enhancement effect of the proposed power amplifier has increased all the more. The measured maximum power added efficiency (PAE) of the proposed power amplifier is 82.68% at 1.71GHz band. Compared with class-F and inverse class-F amplifiers, the measured maximum PAE of the proposed power amplifier has increased in $5.08{\sim}9.91%$.