Julsereewong, Amphawan

Preferred name

Alternative Name

Julsereewong, A.

Main Affiliation

School of Engineering

amphawan.ju@kmitl.ac.th

Now showing 1 - 10 of 71

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Study on field control locations for Foundation Fieldbus-based cascade control loop
(2012-01-01)
Julsereewong, Amphawan
;
Julsereewong, Prasit
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Dejsiriphant, Thipat
This paper focuses on implementing cascade control in the field using Foundation Fieldbus technology. The key consideration is the assignment of master and slave PID block locations in Fieldbus devices for minimizing network traffic without negative impact on an ability to control the process. A plant model using multi-vendor Fieldbus devices for level-to-flow cascade control is described as an illustrative case study. This paper examines calculated macrocycle timing schedules produced by the DeltaV system for six possible field control locations of the PID blocks. Experimental results obtained from the preferred field control location with minimum number of scheduled data transmissions over the network are also included. © 2012 SICE.
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Analog median filtering circuit using CMOS three-input max/min cell
(2018-06-08)
Wongjan, Anan
;
Julsereewong, Amphawan
;
Junsing, Tipparat
This paper presents a current-mode design technique for complementary metal oxide semiconductor (CMOS) implementation of an analog median filtering circuit for real-time signal processing. The proposed three-input median filtering circuit consists of three-input maximum/ minimum (max/min) cell, dual-output current mirrors, and current summation. The max/min cell used is based on an existing multiple-input max/min circuit for simultaneously determining the maximum and minimum values of input signals to overcome the limitations of tree realization by using two-input max/min selectors. Additionally, transistors used in the max/min cell are biased at the edge of conduction to minimize corner errors. PSPICE simulation results are given to verify the operation of the proposed median filtering circuit.
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Foundation fieldbus-based laboratory: A case study of Harmonas-DEO system
(2011-01-01)
Thepmanee, Teerawat
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Pongswatd, Sawai
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Julsereewong, Amphawan
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Julsereewong, Prasit
This paper presents a Foundation Fieldbus-based laboratory for education of automation infrastructure. Design and implementation of a level-control plant model using multi-vendor field devices is proposed. Harmonas-DEO fieldbus system is described as an illustrative case study for configuring and commissioning fieldbus segment, defining control strategy, designing human machine interface (HMI) screen, and troubleshooting. Fieldbus control valve diagnostics based on the use of Valstaff are also included. © 2011 SICE.
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Digital fieldbus-Analog system integration for revamping projects
(2013-01-01)
Thepmanee, Teerawat
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Pannil, Pittaya
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Pongswatd, Sawai
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Rerkratn, Apinai
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Julsereewong, Amphawan
This 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.
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Enhanced differential voltage-to-Frequency converter for telemetry applications
(2010-01-01)
Petchmaneelumka, Wandee
;
Julsereewong, Amphawan
This paper presents an enhanced differential voltage-to-Frequency (dVFC) suitable for telemetry applications. The realization method employs op-amps in conjunction with current conveyors and Set-Reset latch. The converter gain can be easily adjusted through the variation of a single resistor. Compared to the previous dVFC using only current conveyors and Set-Reset latch, the proposed converter offers significant improvements in accuracy and circuit configuration. Its benefits are higher accuracy, simpler structure, fewer components, and lower costs. Experimental results verifying performances of the proposed dVFC are closely agreed with expected values. © 2010 SICE.
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Design of a non-thermal food processing system utilizing wire discharge of dual electrodes in underwater
(2018-06-01)
Eguchi, Kei
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Jaiwanglok, Anurak
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Julsereewong, Amphawan
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Asadi, Farzin
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Abe, Hiroto
To provide nutritious and fresh processed foods, non-thermal food processing technologies have been developed in recent years. Among others, a non-thermal food processing method utilizing underwater shockwaves has cost-effectiveness. In this method, the design of a high voltage multiplier and its discharging method are key factors for processing target foods effectively. This paper proposes a non-thermal food processing system utilizing wire discharge of dual electrodes in underwater. Unlike conventional non-thermal food processing systems, the proposed system has two pairs of electrodes with thin metal wires. Owing to the electric discharge using thin metal wires, the energy to generate underwater shockwaves can be decreased. For this reason, by only one electric discharge, both sides of the target food are crushed by the proposed technique. The experiments using a laboratory prototype clarified that the proposed method can soften the whole flesh of the target food effectively. Furthermore, by assuming a four-terminal model, an equivalent model of the high voltage multiplier was analyzed theoretically. Concerning the series-connected voltage multiplier, the design conditions were derived to estimate the characteristics such as output voltage and power efficiency.
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Simple vector summation circuit using opamps
(2011-01-01)
Kamsri, Thawatchai
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Julsereewong, Amphawan
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Keawpoonsuk, Anucha
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Petchmaneelumka, Wandee
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Riewruja, Vanchai
This paper presents a vector summation circuit using operational amplifiers (opamps) for multiple voltage inputs. The implementation method based on the opamp supply-current sensing utilizes an inherently quadratic characteristic of the opamp class-AB output stage. The distinguishing features of the proposed implementation are simple configuration and low cost. Experimental results verifying the performances of the proposed vector summation circuit are included. © 2011 SICE.
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Simple square-rooting voltage-to-frequency converter using opamps
(2010-12-01)
Maneechukate, Thongchai
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Yaonun, Tawatchai
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Kamsri, Thawatchai
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Julsereewong, Amphawan
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Riewruja, Vanchai
This paper presents a simple method based on commercially available operation amplifiers (Opamps) for realizing the square-rooting voltage-to-frequency converter (VFC). The realization of square-root function is provided through the use of the opamp supply-current sensing, which utilizes an inherent quadratic characteristic of the opamp class-AB output state. Experimental results verifying the performances of the proposed square-rooting VFC are included. ©ICROS.
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Design of a nesting-type switched-capacitor AC/DC converter using voltage equalizers
(2017-01-01)
Eguchi, Kei
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Junsing, Tipparat
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Julsereewong, Amphawan
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Do, Wanglok
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Oota, Ichirou
For electric appliances, an electric circuit that changes an alternating current (ac) into a direct current (dc) is necessary. Among others, a small and light ac/dc converter is indispensable to develop novel mobile devices. As one of the most promising design approaches, the ac/dc converter designed by switched-capacitor (SC) techniques attracts many researchers’ attention, because the SC ac/dc converter can be implemented without a high turn ratio transformer. Owing to the heavy transformer-less design, the SC ac/dc converter can realize smaller size and lighter weight than traditional ac/dc con-verters. However, the SC ac/dc converter suffers from complexity of the circuit control and the inflexibility of conversion ratio. To overcome these problems, this paper proposes a nesting-type SC ac/dc converter using voltage equalizers. Unlike conventional SC ac/dc converters, the proposed converter consists of a full waveform rectifier with a big capaci-tor and nested voltage equalizers. In the nested voltage equalizers, a part of the capacitor voltage of a voltage equalizer is converted by other voltage equalizers, where each voltage equalizer is controlled by non-overlapped two-phase clock pulses. By the nesting conver-sion, the conversion ratio of the proposed converter is expressed as a reverse value of the total sum of main capacitors’ voltage ratios. Therefore, the proposed converter can achieve not only simple circuit control but also flexible conversion ratios. Concerning the 1/9× step-down SC ac/dc converter, the advantages of the proposed converter were investigated by theoretical analysis, simulated program with integrated circuit emphasis (SPICE) simulations, and experiments. First, mathematical formulas for estimating the characteristics of the proposed converter were derived theoretically by utilizing a simple four equivalent circuit. Then, by comparing the proposed converter with conventional SC ac/dc converters, the effectiveness of the proposed converter was clarified by SPICE simulations. Finally, the feasibility of the proposed converter was confirmed by using the experimental circuit implemented on a breadboard.
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Safety and availability of basic process control using foundation fieldbus with control in the field - An experimental analysis
(2017-08-01)
Sangsuwan, Thaksin
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Thepmanee, Teerawat
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Julsereewong, Amphawan
Detailed knowledge of how to balance between safety and availability for instruments is essential to successful design and implementation in fieldbus-based process control systems. The configuration correctness is crucial to actually obtain the benefits of digital fieldbus technology used. In actuality, a number of device parameters must be set to provide the required functionalities. This paper focuses on improving safety and availability for the proportional-integral-derivative (PID) and cascade control strategies using Foundation Fieldbus (FF) with control in the field. The aim of this paper is to analyze the logical behaviors of PID and cascade loops in two conflicting purposes for studying how different configuration options affect the interlocks between function blocks located in instruments as well as the initialization and fail-safe mechanisms in response to invalid measurements. For safety purpose, the interested control loops are configured to bring the process to a safe state in the presence of a fault. For availability purpose, the interested control loops are configured to keep the process running in the event of a failure. A water tank process is utilized as a case study for control loop implementations. Interactions between the status propagation and mode shedding for demonstrating the studied control loop behaviors are examined experimentally in Petri net models. In addition, the function block options for bumpless transfer and setpoint tracking are also described. The proved configuration method for proper operations in balancing the interests of safety and availability is proposed.

Julsereewong, Amphawan

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