• Journal of the Institute of Convergence Signal Processing
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• v.10 no.4
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• pp.289-293
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• 2009

This study proposes a novel double-base log encoder (DBLE) for flash Analog-to-Digital converters (ADCs). Analog inputs of flash ADCs are represented in logarithmic number systems with bases of 2 and 3 at the outputs of DBLE. A look up table stores the sets of exponents of base 2 and 3 values. This algorithm improves the performance of a DSP (Digital Signal Processor) system that takes outputs of a flash ADC, since the double-base log number representation does multiplication operation easily within negligible error range in ADC. We have designed and implemented 6 bits DBLE implemented with ROM (Read-Only Memory) architecture in a $0.18\;{\mu}m$ CMOS technology. The power consumption and speed of DBLE are better than the FAT tree and binary ROM encoders at the cost of more chip area. The DBLE can be implemented into SoC architecture with DSP to improve the processing speed.

• Journal of Power Electronics
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• v.5 no.1
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• pp.45-54
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• 2005

This paper presents an application of SR drives for LSEV's(Low Speed Electric Vehicles) which are used for golf and leisure. Two types of 5[HP] SRM's and its drive system are designed and tested. In order to be energy saving and have effective braking during deceleration, a multi-level inverter is proposed. For the precise switching angle control, a new type of analog encoder is proposed. A current control is adopted for soft starting and an angle control is adopted at high speed to increase efficiency. Drive characteristics and performance are shown with test results.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1216-1219
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• 2003

The position control is very important in semiconductor manufacturing devices, precision machining tools, precision measuring instruments, etc. The accuracy of measurement for the distance in these devices affect on the performance of the whole devices. Therefore, in those precision instruments, a sensing device that can measure the distance of movement with high-precision resolution is required. In this paper, a novel hybrid (digital and analog) type encoder is proposed. It is shown that from several experiments, a high-resolution angular position measurement device can be designed with a low cost incremental encoder and a DSP controller.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1183-1190
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• 2001

In this paper, it used a different pipeline method from conventional method which is encoding the video signal of analog with digital. It designed with pipeline structure of 4 phases as the pixel clock ratio of the whole operation of the encoder, and secured the stable operational timing of the each sub-blocks, it was visible the effect which reduces a gate possibility as designing by the ROM table or the shift and adder method which is not used a multiplication flag method of case existing of multiplication of the fixed coefficient. The designed encoder shared with the each sub-block and it designed the FPGA using MAX+PLUS2 with VHDL.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.237-239
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• 2005

This paper describes the ultra precise position estimation of a servomotor using sinusoidal encoder based on Arcsine Interpolation Method. The amplitude and offset errors of the sinusoidal encoder output signals are effectively compensated and on-line tuned by utilizing a low cost programmable differential amp without any special expensive equipments. To theoretically evaluate the practical resolution of this system, the relationship between the amplitude of A/D converter input signal errors and the anticipated resolution is briefly dealt with. The performance of the proposed method is verified by the experiments, by comparing it with position and speed control characteristics of the servomotor driving system using a digital incremental 50,000ppr encoder.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.197-200
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• 2002

In this paper, presents a 1.8V 8-bit 300MSPS CMOS Subranging Analog to Digital Converter (ADC) with a novel reference multiplex is described. The proposed hか converter is composed of Sub A/D Converter block, MUX (Multiplexer) block and digital block. In order to obtain a high-speed operation, further, a novel dynamic latch, an encoder of novel algorithm and a MUX block are proposed. As a result, this A/D Converter is operated 100MHz input frequence by 300MHz sampling rate.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.1
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• pp.87-94
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• 2005

This paper is about the compensation of phase angle error and amplitude difference in stationary 2 pole coordinates by the installation variation of sensor at low cost high resolution digital hybrid encoder. To solve the problem of amplitude difference at the existing hybrid encoder, we normalized the relative magnitude of the two analog signals. and also to solve the problem of installation variation when installed the sensor, we rotate the stationary 2 pole coordinates to compensate the location error of sensor. and we used and tested the QEP function and A/D port in DSP(TMS320F2812) to verify the mentioned proposed method.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.878-882
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• 2004

Position controls are very important in semiconductor manufacturing devices, machine tools precision measuring instruments, etc. In this paper, a novel encoder of digital and analog hybrid type is proposed. It is shown that from this experiment a high-resolution angle measurement device can be designed by a low cost incremental encoder.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.219-223
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• 2004

Since rotor position information is necessary to drive the SRM, absolute-encoder, resolver and incremental encoder is used to detect a rotor position. But, it is not desirable to use a high price encoder and microprocessor under the condition of the simple driving system when precision control is not demanded. In this paper, only using the reflective type two photo-sensors replaces the conventional opto-interrupter and slotted-disk, which not only remove a slotted-disk section but drive three-phase 6/4 pole SRM bidirectionally, Therefore, control circuit can compose common analog device with low price.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.898-900
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• 2001

In general, the accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor. But the region of high speed, switching angles are fluctuated back and forth from the preset values, which are cause by the sampling period of the microprocessor. Therefore, the low cost linear encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple analog type switching logic circuit is also presented in this paper.