Wandee Petchmaneelumka

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This paper presents the Pulse Induction Metal Detector Using Sample and Hold Method. The proposed method is to measure output voltage from search coil. The system consists of the pulse generator circuit, amplifier circuit, integrator circuit, three mono-stable circuits, sample and hold circuit, comparator circuit and display circuit. The voltage output(More)
A method for realizing a floating resistor based on operational transconductance amplifiers (OTAs) is presented in this paper. The proposed design is composed of only OTAs without any external resistor. The magnitude of the obtained resistance is electronically varied by adjusting the external bias currents of OTAs. Both a positive and a negative resistance(More)
In this paper, a triangular-to-sawtooth waveform converter and a control logic circuit have been described. Using two designed circuits connected with OTA-based sine-to-triangular wave converter and demodulator, a resolver-to-DC converter is proposed. The converter linearly produces output signal proportional to the shaft angle in full range of 360deg.(More)
A simple technique for implementation of resolver-to-DC converter is presented in this paper. The obtained output in form of DC voltage is linearly proportional to the position of motor shaft angle. The configuration of proposed converter consists of commercial available circuit building blocks such as demodulator, sine-to-triangular wave converter, logic(More)
This paper presents an interfacing circuit for capacitive sensor using charge amplifier formed a capacitance-to-voltage converter. The proposed circuit is suitable for the front-end analog-to-digital converter (ADC) and wide variable range of sensing capacitance. The achieved output voltage provides a linear transfer characteristic and fast response. The(More)
A method for realization of resistance-to-period converter is introduced in this article. The principle of converter utilizes the behavior of designed astable multivibrator, which is implemented using commercial available and low cost devices. The operation of proposed converter circuit is in current mode. Therefore, the resistance is linearly converted to(More)
A simple interface circuit for single resistive sensor-based remote measurements is presented. The realization method using commercially available devices provides not only the output signal linearly related to resistive sensor changes but also the compensation of effect due to lead-wire resistances. Performance of the proposed circuit is confirmed through(More)
This paper presents a simple circuit technique based on commercially available devices for measuring the amplitude of transient signals. The proposed technique produces digital output proportion to the amplitude of sinusoidal analog input signal without low-pass filter. The realization method employs a peak detector, a comparator, an analog-to-digital(More)
A circuit technique to implement a floating inductance simulator using operational transconductance amplifiers (OTAs) is introduced in this paper. The realization method based on the commercially available OTA, one resistor and one capacitor provides the advantage of an electronic adjusting capability. The resulting inductance can be electronically varied(More)
This 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.(More)