• Journal of information and communication convergence engineering
• /
• v.14 no.4
• /
• pp.268-271
• /
• 2016

An efficient inductive switching noise suppression technique for mixed-signal integrated circuits (ICs) using standard CMOS digital technology is proposed. The proposed design technique uses a parallel RC circuit, which provides a damping path for the switching noise. The proposed design technique is used for designing a mixed-signal circuit composed of a ring oscillator, a digital output buffer, and an analog noise sensor node for $0.13-{\mu}m$ CMOS digital IC technology. Simulation results show a 47% reduction in the on-chip inductive switching noise coupling from the noisy digital to the analog blocks in the same substrate without an additional propagation delay. The increased power consumption due to the damping resistor is only 67% of that of the conventional source damping technique. This design can be widely used for any kind of analog and high frequency digital mixed-signal circuits in CMOS technology

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.20 no.1
• /
• pp.295-303
• /
• 1996

A new temperature compensation technique for hot-wire anemometer is proposed in this article. In contrast to the available compensation techniques, a photoconductive cell is introduced here as a variable resistor in the bridge. The major advantage of adopting an active component such as photoconductive cell is that temperature compensation can be achieved by using any kind of temperature sensors, once the output of temperature sensor is given as a voltage. Thereby, the temperature compensation can be made automatically and intelligently by a computer software or a hardware device. Validation experiments using a photoconductive cell with a thermocouple-thermometer are conducted in the temperature range from 3$0^{\circ}C$ to 5$0^{\circ}C$ and the velocity ranges from 8 m/s to 18 m/s.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.688-692
• /
• 2016

S4A means a program that controls the Arduino to the scratch. In this paper, development for gmae education content that using S4A language and combination the Arduino sensors. It this content developed by game moving images and sound to enhance the interest of students.

• Journal of Sensor Science and Technology
• /
• v.30 no.2
• /
• pp.99-104
• /
• 2021

In this study, we utilized the duty factor of the transition frequency modulation (TFM) for the illumination control of the light emitting diode (LED) light in visible light communication (VLC). The average optical power is linearly proportional to the duty factor in TFM waveforms. We used the transition frequencies of Na=5 and Nb=1 for the high and the low bits, respectively, of the non-return-to-zero (NRZ) data in the VLC transmitter. A resistor and capacitor high-pass filter (HPF) was used in the VLC receiver to eliminate the 120 Hz optical noise from adjacent lighting lamps and the spikes at the HPF output were used to recover NRZ data from the TFM waveform. In experiments, the illumination of the LED light was controlled in the range of 25-90% of the constant-wave optical power by changing the duty factor of the TFM waveforms.

• Journal of Sensor Science and Technology
• /
• v.10 no.3
• /
• pp.148-155
• /
• 2001

A pressure sensor on the tip of a catheter which is utilized to measure the in-vivo pressure in a human body was fabricated and the characteristic of the pressure sensor as measured. To fit into a catheter with 1 mm caliber, samples of $150\;{\mu}m$(thickness) ${\times}$ (600, 700, 800, 900, 1000) ${\mu}m$(width) ${\times}2\;mm$(length) was fabricated. The thicker face with $450\;{\mu}m$ thickness of SDB wafer was made thin to $134\;{\mu}m$ thickness using KOH etchant and it made possible to fabricate sensor cell with the width shorter than 1 mm. Different to the whitstone bridge sensor, we formed one piezoresistor and one reference resistor in sensor. Therefore there are possibilities of reduction of the sensitivity, then by using the simulation tool ANSYS 5.5.1, the location and the type of the piezoresistor was optimized. Another piezoresistor type of sensor which contain one longitudinal and one transverse piezoresistor was fabricated at the same time, but the sensitivity was not improved very much. To get the output versus the pressure, a constant current source and a implementation amplifier was used. As a result, the maximum sensitivity of the sensor with one piezoresistor was $1.6\;{\mu}V/V/mmHg$.

• Journal of Sensor Science and Technology
• /
• v.7 no.3
• /
• pp.171-178
• /
• 1998

Silicon piezoresistive absolute pressure sensor for gas leakage alarm system was developed. This sensor must operate normally in the range of $0{\sim}600\;mmH_{2}O$ pressure, and $0{\sim}100^{\circ}C$ temperature. To make the most of this sensor for gas leakage alarm system, gas must not leak from the sensor itself when the diaphragm of the sensor fractures. Thus, the sealed diaphragm cavity was anodically bonded to pyrex 7740 glass under the condition of $10^{-4}$ torr, at $400^{\circ}C$. The sensitivity of developed sensor was $4.06{\mu}V/VmmH_{2}O$ for $600\;mmH_{2}O$ full-scale pressure range. And temperature compensation method of this sensor is to change bridge-in put-voltage linearly in proportion to the temperature variation by using diode(PXIN4001) or Al thin film resistor. By these methods the temperature effect in the range of $0{\sim}100^{\circ}C$ was compensated over 80 % for offset drift, 95 % for sensitivity.

• Journal of Sensor Science and Technology
• /
• v.7 no.5
• /
• pp.300-305
• /
• 1998

In this paper, integrated pressure sensor with calibration of offset voltage and full scale output and temperature compensation of offset voltage and full scale output were designed. The signal conditioning circuitry are designed that calibrate the offset voltage and full scale output to desired values and minimize the temperature drift of offset voltage and full scale output. Designed circuits are simulated using SPICE in a bipolar technology. The ion implanted resistor of different temperature coefficient were used to trimming the desired values. As a results, offset voltage was calibrated to 0.133V and the temperature drift of offset voltage was reduced to $42\;ppm/^{\circ}C$. Also, the full scale output was calibrated to 4.65V and the temperature coefficient of full scale output was reduced to $40ppm/^{\circ}C$ after temperature compensation.

• Journal of Industrial Technology
• /
• v.40 no.1
• /
• pp.13-18
• /
• 2020

Lithium-ion batteries have a small volume, light weight and high energy density, maximizing the utilization of mobile devices. It is widely used for various purposes such as electric bicycles and scooters (e-Mobility), mass energy storage (ESS), and electric and hybrid vehicles. To date, lithium-ion batteries have grown to focus on increasing energy density and reducing production costs in line with the required capacity. However, the research and development level of lithium-ion batteries seems to have reached the limit in terms of energy density. In addition, the charging time is an important factor for using lithium-ion batteries. Therefore, it was urgent to develop a high-speed charger to shorten the charging time. In this thesis, a discharger was fabricated to evaluate the capacity and characteristics of Li-ion battery pack which can be used for e-mobility. To achieve this, a smart discharger is designed with a combination of active load, current sensor, and temperature sensor. To carry out this thesis, an active load switching using sensor control circuit, signal processing circuit, and FET was designed and manufactured as hardware with the characteristics of active discharger. And as software for controlling the hardware of the active discharger, a Raspberry Pi control device and a touch screen program were designed. The developed discharger is designed to change the 600W capacity battery in the form of active load.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.3
• /
• pp.116-124
• /
• 2011

In this study, a new method to estimate the bridge deflection is developed by using Wireless Tilt Sensor. Most of evaluations of structural integrity, it is very important to measure the geometric profile, which is a major factor representing the global behavior of civil structure, especially bridges. In the past, Because of the lack of appropriate methods to measure the deflection curve of bridges on site, the measurement of deflection had been done restrictly within just a few discrete points along the bridge. Also the measurement point could be limited to locations installed with displacement transducers. So, in this study, the deflection of the structure was measured by wireless tilt sensor instead of LVDT(Linear Variable Differential Transformer). Angle change of tilt sensor shows structural behavior by the change of the resistor values which is presented to voltage. Moreover, the maximum deflection was calculated by changing the deflection angle which was calculated as V(measured voltage) ${\times}$F(factor) to deflection. The experimental tests were carried out to verify the developed deflection estimation techniques. Because the base of tilt measuring is the gravity, uniform measurement is possible independent of a measuring point. Also, measuring values were showed very high accuracy.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.10
• /
• pp.851-856
• /
• 2015

This study aimed to develop a sensory feedback system which could measure force and temperature for the user of myoelectric prosthetic hands. The Sensory measurement module consisted of a force sensing resistor to measure forces and non-contact infrared temperature sensor. These sensors were attached on the fingertips of the myoelectric prosthetic hand. The module was validated by using standard weights corresponding to external force and a Peltier module. Sensory transmission module consisted of four vibration motors. Eight vibration patterns were generated by combining motion of each vibration motor and were dependent on kinds and/or magnitude. The module was verified by using standard weigts and water at varying temperatures. There were correlations of force and temperature between the sensory measurement module and standard weight and water. Additionally, exact vibration patterns were generated, indicating the efficacy of the sensory feedback system for the myoelectric prosthetic hand.