Riewruja, Vanchai
Loading...
Preferred name
Riewruja, Vanchai
Alternative Name
Riewruja, V.
Main Affiliation
Email
vanchai.ri@kmitl.ac.th
35 results
Now showing 1 - 10 of 35
- Some of the metrics are blocked by yourconsent settings
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, Electronically adjustable phase shifter using OTAs(2010-12-01); ; First-order phase shifter using operational transconductance amplifiers (OTAs) as active elements is presented in this paper. The corner frequency of the proposed phase shifter can be adjusted by electronic means. The purpose of this paper is emphasized on simple configuration and low cost. The phase response between input and output signals against the operating frequency is varied from 180 to 0 degrees of phase lead. The principle of the proposed circuit is confirmed by simulation and experimental results. To verify the proposed circuit performance, the sinusoidal oscillator is provided for circuit application. ©ICROS. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced sinusoidal amplitude detector for fast response applications(2013-03-28); In this paper, an enhanced sinusoidal-amplitude detector suitable for fast response applications is proposed. Implementation method based on commercially available devices employs a novel control signal generator to improve operation speed of previously reported sinusoidal amplitude detector. The control signal generator used consists of a time-delay circuit, AND logic gate, and three comparators. The enhanced amplitude detector provides faster amplitude detection as well as smaller operation error for amplitude input changes. Experimental results verify a good agreement with theoretical expectation. © 2013 ICIC International. - 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, Power monitoring circuit using operational amplifiers(2010-12-01); ; - 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, 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, Accurate LVDT signal converter(2016-01-01); ; A novel technique to implement a signal converter for an inductive displacement transducer, a linear variable differential transformer (LVDT), is proposed in this paper. The technique is based on the use of the proposed peak-amplitude finder and the zero-order sample and hold circuit (ZSH) instead of the synchronous demodulator used in traditional approach. The advantage of this technique is that the phase shift due to the dominant pole of the low-pass filter used in the traditional synchronous demodulator is avoided. Therefore, the fast response time of the proposed LVDT signal converter is achieved. The core displacement signal, which is varied in proportion to the position of the moving core of the LVDT, is accurately extracted to directcurrent (DC) voltage signal. The reference signal used to generate the control signal for the ZSH is directly provided by the output signal of the LVDT to prevent the phase shift caused by the LVDT structure. Performances of the proposed technique are discussed in detail and confirmed by the experimental demonstration using commercial devices. The purpose of the proposed technique is emphasized in terms of high accuracy, fast response, simple configuration and low cost. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simple vector summation circuit using opamps(2011-01-01); ; 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, Simple square-rooting voltage-to-frequency converter using opamps(2010-12-01); 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.