Petchmaneelumka, Wandee
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Preferred name
Petchmaneelumka, Wandee
Alternative Name
Petchmaneelumka, W.
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Email
wandee.pe@kmitl.ac.th
66 results
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Item type:Publication, Linear Variable Differential Transformer Signal Conditioning Circuit Based on Phase-Locked LoopThe purpose of this paper is to propose a novel technique for extracting the position signal from an inductive displacement transducer named a linear variable differential transformer (LVDT). In general, the movement of the LVDT core causes its primary inductance change in linear form. The primary winding of the LVDT is used as a time-dependent element for the triangular and square wave generator, which can be called self-oscillation, to generate frequency. The advantage of the proposed technique is that it can measure the displacement using the LVDT without an external oscillator. The change in primary inductance causes the frequency deviation generated by the oscillator. The deviated frequency is captured and converted into a voltage signal using the principle of the phase-locked loop. All the components used in this study are commercially available. The merits of this proposed technique are simple configuration, small size, and low cost. Moreover, the operating range of the LVDT can be extended without the limitation of the nonlinear transfer characteristic. The performance of the proposed technique is discussed in detail and confirmed by experimental implementation. Experimental results show that the maximum error from the proposed technique is about 0.42% and the operating range of the LVDT can be extended to more than 200%. It can be seen that the proposed technique is suitable for embedded measurement in small or micro robots. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 8-Electrode data collection system for electrical capacitance tomography(2006-12-01); ;Lertpakdee, Thanakorn ;Chitsakul, Kitiphol ;Sangworasil, Manas8-electrode data collection system for electrical capacitance tomography is presented. The system mainly consists of a signal generator, 8×2 multiplexer, detector, amplifier, band-pass filter, rms-to-dc converter, A/D converter circuit and control computer. Experimental results with a circular sensor show that the proposed system is able to collect data with satisfy sensitivities, linearity, resolution and also being insensitive to noise. Reconstructed images from collected data are shown. © 2006 ICASE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Advanced planning for multi-product across a supply chain(2009-04-23) ;Masuchun, RuedeeThis paper presents a linear integer programming model to plan the production for multiple products. The production is planned using information shared across a supply chain. The advantage of information sharing has been proved from research that it can make the whole supply chain globally visualized and yet decreasing in variability on the supply chain. The objective function of the proposed model is to minimize the total costs involved including the production costs, the distribution costs, the setup costs of manufacturing, and the fixed costs of distributing. From previous research, one more restriction which is limitation of distribution centers has been added to make the model more realistic. Numerical results verify that this model can be used to generate feasible and optimal plans for multiple products across the supply chain. © 2009 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simple LVDT signal to DC converter(2017-02-18); ; A simple technique to produce a linear signal from a displacement transducer, linear variable differential transformer (LVDT), is introduced in this paper. The two-quadrant divider is used to precede the ratio of a different and sum of the two winding signals from the LVDT instead of a four-quadrant divider of a recent approach. The two- quadrant divider is obtained by an operational transcondutance amplifier (OTA) in the form of a voltage-tocurrent converter. The signal from the divider is held by the sample and hold circuit (SHC) controlled by the peak-amplitude finder. As a result, the held signal is achieved without using a low-pass filter. The temperature effect of both OTA and LVDT are compensated. The merit of the proposed technique is that the circuit requires without the low-pass filter. Therefore, the fast response is obtained. The performance of the proposed scheme is confirmed by the experimental results using commercial devices. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A current signal CMOS sample-and-hold circuit(2007-12-01) ;Luangpol, Amata; ;Kamsri, ThawatchaiThis article presents a current signal sample-and-hold (S/H) circuit using 0.5μm CMOS technology. A current minimum circuit is used to sample the input signal in place of a sampling switch used in the conventional S/H circuit. The current peak detector is used to hold the signal from the minimum circuit in the "hold" state. The proposed configuration is adopted effectively to cancel switch feedthrough error. The performances of the proposed circuit are demonstrated using the PSPICE analog simulation program. Simulation results show the sampling frequency up to 100MHz and high accuracy. © ICROS. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simple vector summation circuit using opamps(2011-01-01) ;Kamsri, Thawatchai; ;Keawpoonsuk, Anucha; 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Position signal detector for linear variable differential transformer(2020-12-01); ;Luangpol, Amata; This paper presents the position signal detector for linear variable differential transformer (LVDT) based on RMS-to-DC converter. The proposed detector consists of the differential amplifier, the comparator, the phase detector, the controllable unity-gain inverting/non-inverting amplifier and the RMS-to-DC converter. The proposed technique provides a simple scheme and uses the low cost commercial available devices such as opamp, transistor and digital logic gate. The experimental testing with the commercial LVDT model OP12.5G from Solartron Metrology showing the proposed position signal detector can produce the output voltage corresponding to the measured displacement with satisfactory values and good linearity. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simple LVDT demodulator(2020-10-13); ;Luangpol, Amata; A simple technique to realize demodulator for linear variable differential transformer (LVDT) is presented in this paper. The proposed LVDT demodulator is based on sample and hold technique. The proposed scheme consists of peak detector, phase detector, monostable circuit, sample and hold circuit, and controllable unity-gain inverting/noninverting amplifier. The presented technique employs the simple and low-cost devices such as op-amp, and digital logic gate. Experimentation with the commercial LVDT model OP12.5G from Solartron metrology shows that the proposed LVDT demodulator provides the output voltage corresponding to the movement of LVDT core with satisfactory values and good linearity. The maximum error of the proposed demodulator is about 1.5%. In addition, the output magnitude of proposed LVDT demodulator can be adjusted by variable resistor (VR1) without the external circuit requirement. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A gray-code algorithmic analog-to-digital converter based on operational conveyors(2010-01-01); This paper presents one-bit cell supporting input voltage to synthesize triangular-like DC transfer characteristic and digital output of Gray-code algorithmic analog-to-digital converter. The proposed one-bit cell is based on the use of operational conveyors in connection with resistors, diodes, and voltage comparator. An N-bit resolution can be simply realized by cascading the N proposed one-bit cells. Surpassing the previous one-bit cells using operational transconductance amplifiers, the proposed converter affords higher resolution and simpler configuration. The circuit operations of the proposed converter are confirmed through PSPICE simulation and experimental results. ©ICROS. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A current-mode CMOS sample-and-hold circuit for ADC(2006-12-01) ;Mahatthumthanant, Phinet ;Kamsri, Thawatchai; ;Sungkabunchoo, TiparatThis paper presents a current-mode sample-and-hold circuit using 0.5μm CMOS technology. The input signal is sampled using a current subtracter and a half wave rectifier instead of a sampling switch used in the conventional sample-and-hold circuit. As a result, the switch feedthrough error is eliminated. The proposed circuit achieves high sampling frequency up to 100MHz and high accuracy. The performances of the proposed circuit are demonstrated by PSPICE simulation results. © 2006 ICASE.
