Chaichana, Amornchai
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Chaichana, Amornchai
Alternative Name
Chaichana, Amonchai
Chaichana, Amornchia
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Email
amornchai.ch@kmitl.ac.th
38 results
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Item type:Publication, Current-mode MISO filter using CCCDTAs and grounded capacitors(2015-07-01); ; This paper presents the current-mode multi-input single-output (MISO) biquadratic filter using current-controlled current differencing tranconductance amplifier (CCCDTA) as an active building block. The proposed circuit comprises three CCCDTAs and two grounded capacitors performing completely standard functions: low-pass, high-pass, band-pass, bandreject and all-pass functions and does not require double input current signals as well as inverting input currents. The pole frequency and quality factor of the proposed circuit can be adjusted electronically/independently via dc bias currents. In addition, the filter circuit has low-input and high-output impedance which facilitates easy connecting for current-mode circuit. The proposed circuit uses all grounded capacitors which is very suitable to further develop into an integrated circuit and without requiring any matching condition. Moreover, the active and passive sensitivities are low. The PSPICE simulation results are included to show the workability of the proposed circuit. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis of electronically tunable multifunction biquad filter using voltage differencing differential input buffered amplifiers(2025-02-01); ; ; Biquad filters are commonly used in analog circuits for various purposes in signal processing and communication applications. We synthesize an analog active biquad filter with five types of voltage-mode filtering functions. The filter is synthesized using a parallel passive resistor-inductor-capacitor (RLC) network and unity-gain voltage differencing amplifier. A voltage differencing differential input buffered amplifier (VD-DIBA) is the main active component, and the biquad filter has a three-input single-output (TISO) topology. By replacing the passive inductor and resistor with VD-DIBA-based inductance and resistance simulators with a subtractor, the TISO voltage-mode versatile filter is obtained from two VD-DIBAs, one resistor, and two capacitors connected to the ground. The proposed filter can provide five types of voltage-mode filtering functions: inverting bandpass and lowpass responses as well as noninverting band-stop, high-pass, and all-pass responses. The all-pass filter requires no additional active components. The three input voltage nodes have high impedance, and a low-impedance output voltage node facilitates cascade connections without using additional voltage buffers. In addition, the natural frequency and quality factor can be electronically tuned. The quality factor is controlled without disturbing the passband gain and natural frequency. The proposed filter is simulated and verified experimentally in the Personal Simulation Program with Integrated Circuit Emphasis (PSPICE) and through laboratory tests employing VD-DIBAs implemented using commercially available components. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Single Active Element Based Electronically Controllable Capacitance Multiplier(2022-07-15); ; ; The realization of capacitance multiplier using the versatile active building block, namely voltage differencing differential difference amplifier (VDDDA) is presented in this paper. The realized capacitance multiplier is very simple consisting of one VDDDA, one MOS resistor (RM) and one grounded capacitor which is attractive for integration. The multiplication factor (KC) of the realized circuit can be electronically controlled via the bias current (IB) and control voltage (VC) without the need of any matching condition of active and passive element. Moreover, the multiplication factor can be adjusted to be more or less than one. The performances of the presented capacitance multiplier are verified through Pspice simulation using CMOS VDDDA in 0.18μm TSMC technology with ±0.9V power supplies. The multiplication factor is designed to be KC=2 by choosing VC=0.85V, IB=50μA and C=30 pF. The simulated multiplication factor is around 1.98. The simulated operational frequency range is around three decades (6.16 kHz-8.91MHz). The performances of the proposed circuit are also verified by the experiment using VDDDA implemented from the commercial ICs, AD830 and LM13700 with ±5V power supplies. The experiment is conducted under the same multiplication factor (KC=2) as the simulation by choosing RM=0.27 kω (1% passive resistor), IB=96.2μA and C=1nF. The experimental multiplication factor is around 2.06. The experimental operational frequency range is around three decades (1kHz-1.25MHz). By adjusting the bias current from 17.67μA to 400 μA, the experimental multiplication factor is controllable from 11.47 to 0.48. The percent deviation of the theoretical and experimental multiplication factor is lower than 5% when the value of bias current is greater than 39μA. These deviations stem from the effect of the parasitic capacitance and resistance in VDDDA. Moreover, the application example of the presented capacitance multiplier as the sinusoidal oscillator is presented. The performances of the presented oscillator verified via the experiment are well consistent with theoretical anticipation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electronically tunable current-mode quadrature oscillator derived from first-order allpass filter(2014-01-01); In this study, an electronic controllability current-mode quadrature oscillator based on first-order all pass filter employing current follower cascaded Tran conductance amplifier (CFCTA) is presented. The proposed oscillator uses two CFCTAs, two electronic resistors and two grounded capacitor, which is easier for monolithic IC implementation. The condition of oscillation (CO) and frequency of oscillation are electronically and independently controlled which is well suited to use in modern electronic devices controlled by microprocessor. Moreover, the oscillator possesses high output impedances and thus it enables simple current-mode cascading. The PSPICE simulation results are included, verifying the workability of the proposed current-mode oscillator. The given results agree well with the theoretical anticipation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A study of health service accessibility in aging society and technological development: A case of the urban community surround sirinthorn Hospital, Bangkok(2020-11-04); ; ; Munkong, PratumThe situation of health in aging society and the issues on travelling in city communities in Bangkok have a relationship with its environment where is under an investigation of health activities and patterns of travelling among the elderly. This research aims to examine health activities, patterns of travelling and factors influencing health service assess in city communities among the elderly. Following the objectives of the present study, suggestions for further development are given to relevant departments.The major findings of the situation on travelling and problems on receiving health service of the elderly who have lived in city communities of Sirindhorn hospital, Bangkok leads to some recommendations for developing patterns of travelling for health service, designing activities for the elderly with different ages to have appropriate health service and promoting an engaging environment in the communities - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electronically and orthogonally tunable sito voltage-mode multifunction biquad filter using lt1228s(2021-10-27); ; The commercially available IC LT1228 is an interesting active device due to its advantage features, such as a fast transconductance amplifier, a wide bandwidth over a wide range of voltage gain, low total harmonic distortion (THD), high impedance differential input, etc. The single-input triple-output (SITO) voltage-mode (VM) multifunction biquadratic filters using ICs, LT1228s are introduced in this research. This circuit design provides the three-filtering functions, low-pass (LP), high-pass (HP), and band-pass (BP), without changing the circuit architecture. It comprises three LT1228s, four resistors, and two capacitors connected to the ground. The low impedance voltage output nodes are HP and BP responses. The quality factor (Q) and the pole frequency (ω0) can be electronically and orthogonally tuned by altering the third LT1228's bias current (IB). The PSPICE simulation and the experiment are verified to describe the circuit operation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Classroom Management as Virtual World for Creating Professional Teaching Environment(2024-01-01); ; Phetsinchorn, AueamaumpornResearch and innovation for community or local development, aims at providing the individuals with a high quality of life and enhancing capabilities for competition through collaborative efforts of stakeholders, including beneficiaries in the area, especially the academic sector of which powerful educational institutions in the central and metropolitan areas of Thailand. Innovation in vocational education management through online teaching environments intends to have educational innovations in the central and metropolitan areas as a mechanism and process of educational reform that can manage online teaching in line with the local context. This involves flexible and adaptable management that eliminates the need for travel and reduces consumption of resources. This is achieved by research objective of 1) developing innovations in vocational education management through online teaching environments to enhance educational efficiency, 2) reducing educational quality disparities by designing virtual reality training centers for professional skill development, with a case study in the field of art and design, and 3) developing mechanisms for collaborative education management in the community, through the design and use of application programs to create a professional teaching environment. Therefore, this research and innovation in vocational education management in the central region of Thailand through online teaching environments can enhance self-directed learning. This involves designing and developing learning technology, creating a virtual world to establish a professional teaching environment, and innovating learning application programs from 400 sampling. The education system in this changing crisis has a responsibility to stimulate and revive the grassroots economy after the crisis. This emphasizes the crucial role of education as a continuous tool in building economic and social resilience later. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Single commercially available ic-based electronically controllable voltage-mode first-order multifunction filter with complete standard functions and low output impedance(2021-11-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A new quadrature sinusoidal oscillator for telecommunication system using VDDDAs(2016-03-22); ; ; A CMOS voltage differencing differential difference amplifiers (VDDDAs) based voltage-mode quadrature sinusoidal oscillator is proposed. The proposed oscillator is based on the two integrator loop configuration with amplifier wherein the frequency of oscillation (FO) is tuned by the time constant of two integrator and the condition of oscillation (CO) is tuned by gain of amplifier. It is constructed from two VDDDAs, two resistors, and two grounded capacitors. With this structure, it is attractive to develop in monolithic chip. The tuning of frequency of oscillation can be electronically done without affecting the condition of oscillation. Also, the condition of oscillation can be adjusted by external resistor without affecting to frequency of oscillation. The simulation results have been demonstrated and discussed using parameters of 0.18um TSMC CMOS technology and +0.9V power supply voltages. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A New Method to Synthesise the Sinusoidal Oscillator Based on Series Negative Resistance-Capacitance and its Implementation Using a Single Commercial IC, LT1228(2023-01-01); ;