Rerkratn, Apinai
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Rerkratn, Apinai
Alternative Name
Rerkratn, A.
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Email
apinai.re@kmitl.ac.th
41 results
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Item type:Publication, A simple amplitude detector-based demodulator for resolver converters(2010-12-01); This paper presents a simple method based on sinusoidal-amplitude detector for realizing the resolver-signal demodulator. The proposed demodulator consists of two full-wave rectifiers, two ±unity-gain amplifiers, and two sinusoidal-amplitude detectors with control switches. Two output voltages are proportional to sine and cosine envelopes of resolver-shaft angle without low-pass filter. Experimental results demonstrating characteristic of the proposed circuit are included. ©ICROS. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Four-quadrant analogue multiplier using operational amplifier(2011-04-01); A method to realise a four-quadrant analogue multiplier using general-purpose operational amplifiers (opamps) as only the active elements is described in this article. The realisation method is based on the quarter-square technique, which utilises the inherent square-law characteristic of class AB output stage of the opamp. The multiplier can be achieved from the proposed structure with using either bipolar or complementary metal-oxide-semiconductor (CMOS) opamps. The operation principle of the proposed multiplier has been confirmed by PSPICE analogue simulation program. Simulation results reveal that the principle of proposed scheme provides an adequate performance for a fourquadrant analogue multiplier. Experimental implementations of the proposed multiplier using bipolar and CMOS opamps are performed to verify the circuit performances. Measured results of the experimental proposed schemes based on the use of bipolar and CMOS opamps with supply voltage ±2.4 V show the worst-case relative errors of 0.32% and 0.47%, and the total harmonic distortions of 0.47% and 0.98%, respectively. © 2011 Taylor & Francis. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Internet-based conductivity measurement system with self-temperature compensation(2019-07-01); Kaewpoonsuk, AnuchaAn Internet-based conductivity measurement system with self-temperature compensation is presented in the paper. In order to get a simple and portable measurement system, a readout circuit in analog part is designed using only two operational amplifiers (opamps) connected with basic electronic components and energized using single supply voltage. An excitation voltage generated by the AD9833 module is applied to a conductivity sensor. The measured output DC voltages are found to be directly proportional to the conductivity of the solution. The NodeMCU ESP8266 WiFi dev board is used to determine the conductivity and measure the temperature whose effect on the conductivity is compensated. The measured results are sent to display on a smartphone by Blynk app. The conductivity measured by the proposed system is in good agreement with that due to the standard EC meter. A maximum error of measuring the conductivity at different temperatures of solution is 4.79% of full scale. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Digital fieldbus-Analog system integration for revamping projectsThis paper presents a system integration of modern digital fieldbus and traditional analog devices for revamping projects. Using temperature transmitter with Foundation Fieldbus technology and power regulator with 4-20 mA control input for temperature control based on a PID instruction of programmable logic controller (PLC) is examined as an illustrative case study. A portable plant model was designed and implemented for real hands-on training. In addition, basic network and device configurations as well as ladder logic program and graphical user interface creations are discussed. Experimental results of temperature control in the range of 40-60 °C verifying the proposed concept are also included. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simple and low-cost readout circuit for differential resistive sensors(2018-09-01); Kaewpoonsuk, AnuchaIn this paper, a simple and low-cost readout circuit for differential resistive sensors is presented. The realization method is based on the relaxation oscillation technique, which utilizes the operational amplifiers (op-amps) with a single supply voltage. The oscillating output Duty-Cycle is proportional to the difference of two sensing resistances. In comparison with the traditional voltage divider circuit or the Wheatstone bridge circuit or the previously reported readout circuit based on CCIIs, the proposed circuit can be interfaced with microcontroller without using an analog-to-digital converter. Theoretical predictions are supported by the PSPICE simulation results and the experimental data. In applying a slide potentiometer with changes of slider positions of ±15 mm, it is found that the maximum error of the proposed circuit is approximately-2.90% of full-scale. Copyright © 2018 Praise Worthy Prize S.r.l.-All rights reserved. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Power monitoring circuit using operational amplifiers(2010-12-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simple interface circuit for resistive/capacitive sensors(2013-01-01); ; ; This paper presents a method to realize interface circuit for resistive and capacitive sensors. The proposed circuit employs commercially available devices to generate the output signal in form of time period, which is linearly proportional to the both of sensing resistance and capacitance. Circuit configuration is simple and small in size. Experimental results verifying the performances of the proposed circuit are also included. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Hydropower plant generator system(2018-06-08); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Integration of wireless HART network system into SCADA software for operation & management(2016-11-18); ; This paper describes the technique to integrate HART field devices into SCADA (Supervisory Control and Data Acquisition) system. Wire HART field device is connected to WirelessHART adapter (THUM) and WirelessHART device are assigned act as RTU(Remote Terminal Unit) in SCADA system. In system, THUM and WirelessHART device communicate to WirelessHART gateway that collects their data and send to master station with Modbus/TCP. The paper presents the practices to install and configure the THUM with control valve wire HART device, WirelessHART transmitter, tags assignment, and so on that focus for HART parameters mapping in order to device operation and management. Effectiveness of the proposed system integration is verified by simulation and experimental results. Moreover, the technique can be applied in existing plants or in new project to support end-users to quickly and easily gain the benefits of device diagnostic and decision support for operation and management. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Real-time fault notification for billboard lighting system(2017-11-24); Kaewpoonsuk, AnuchaThis paper presents a technique to implement the alert system for the faults of billboard lighting system. The proposed system consists of the current sensor module SCT-013-005 used to measure the overall current consumption of the billboard lighting system, ARDUINO UNO R3 used as the controller to determine the faults, and GSM module used to remotely transmit faulty data to the data server as well as to the user mobile via short message service. The alert data composes the current consumption of lighting system, number of the bulbs with abnormal condition, and identification number of base station. In addition, the conditions for sending notifications can be set. The billboard lighting system using seven bulbs connected in parallel is employed to test the performance of the proposed notification system. Test results verify that the proposed system can function correctly.