• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.14 no.11
• /
• pp.912-916
• /
• 2001

Fluxmeter is a measuring instrument the magnetic flux intensity by means of an integration of the voltage induced to a search coil to unit time. It also is required to a precise integrator since the voltage induced to a search coil has a differential value of the flux ${\Phi}$ to unit time. In this study, a bias current which is a main problem of the integrator in a drift troublesome depending on the temperature of a FET is investigated. We have confirmed that the temperature dependence of both the bias current of a integrator using the FET and the reversal saturated current of the minor carrier in a P-N junction of a semiconductor were the same. The property of a commercial integrator goes rapidly down with increasing temperature. The bias current of a FET is increased twice as much with 10$^{\circ}C$ increment. As a result, the low drift integrator could be developed by setting the lower temperature up with a pottier device.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.551-555
• /
• 2005

This paper presents the temperature-pressure characteristics of SMH actuator using a peltier module. The simple SMH actuator, consisting of the plated hydrogen-absorbing alloy as a power source, Peltier elements as a heat source and a cylinder with metal bellows a functioning part has been developed. The SMH actuator is characterized by its small size, low weight, noiseless operation and a compliance similar to that of the human body. A new special metal hydride(SMH) actuator that uses the reversible reaction between the heat energy and mechanical energy of a hydrogen absorbing ally. It is well known that hydrogen-absorbing alloys can reversibly absorb and desorb a large amount of hydrogen, more than about 1000 times as their own volume. To improve the thermal conductivity of the hydrogen-absorbing alloy, an electro-less copper plating has been carried out. The effects of the electro-less copper plating and the dynamic characteristics of the SMH actuator have been studied. The hydrogen equilibrium pressure increases and hydrogen is desorbed by heating the hydrogen-absorbing alloys, whereas by cooling the alloys, the hydrogen equilibrium pressure decreases and hydrogen is absorbed. Therefor, the SMH actuator has the characteristic of being light and easy to use and so is suitable for use in medical and rehabilitation applications.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.3
• /
• pp.341-346
• /
• 2020

Motion sickness or dizziness caused by visual and other sensory inconsistencies In virtual reality content seems to be a major problem. To solve the problem, research has been actively underway to satisfy the five senses. Among them, the most researches on the touch are many studies on hardness and texture, but the studies on temperature seem relatively small. Therefore, in this paper, we present a calculation model that can sense the temperature derived from the principle of heat energy moving from high temperature to low temperature, not the temperature of the material. Because heat energy is determined by the heat conductivity, temperature, and area of contact, which are the inherent characteristics of a material, the degree of heat felt by a person depends on the type of material, the temperature of the material and the area of contact with the object. The thermal energy shift per unit time of the material was calculated using the thermal conductivity law and the specific heat formula, and the thermal energy reproduction method that changes per unit time of the material was studied using the thermoelectric element.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1547-1552
• /
• 2008

The tip of these catheter with straight needles is not able to reach in the vicinity of the disc bulging, which are the cause of the low back pain and because the far indirect radio-frequency treatment results in the decompression, the nucleoplasty has the limit. Many incurable diseases has not been solved due to the unexistence of the advanced technique for the MIS human body catheter device. To increase the possibility of nucleoplasty, the needle tip should be located at the closest area of the lesion. For this reason, the best way to increase the success rate of the operation is that the needle tip should access 3-dimensionally to the operating field as soon as possible. To achieve this aim, our studies are restricted as follows: 1) the SMA catheter design to control the 3-dimensional direction, 2) the security of the immediate response by the positive control of the SMA element thermal distribution using Peltier thermoelectric elements, 3) the aquisition of the control data by monitoring the relationship between the temperature of SMA element and the displacement, and 4) the design of the controller to guarantee the accurate location.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.17 no.3
• /
• pp.110-116
• /
• 2009

Research for climate control seats is being vigorously pursued because requests for passenger's thermal comfort are increasing. Recently, thermoelectric devices have been applied to automotive seats for both cooling and heating operations. The climate control seats using thermoelectric devices can rapidly control the air temperature passing through the devices and directly affect the thermal comfort of passengers. The performance characteristics of the climate control seats were analyzed by experiments for two different types of a leather covered seat and a mesh applied seat. Experimental results show that the cooling and heating performance for the mesh applied seat by using the discharge port of the shape of nozzle was improved significantly in comparison with that for the leather covered seat. The variation of temperature between the inlet air and the outlet air of the climate control seat for the enhanced mesh applied type was by $-3.5^{\circ}C$ at cooling mode, and was by $15.0^{\circ}C$ at heating mode, after about 30 minutes, respectively. Also, it is possible to provide rapid thermal comfort to passengers sitting on the seat in the vehicle cabin by using the proposed climate control seat.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.93.2-93.2
• /
• 2018

최근 기후 변화 문제로 $CO_2$배출량 억제 정책에 따라 열전재료가 다양한 분야에 크게 주목 받고 있다. 열전 모듈은 전류를 흘려 온도차를 발생시키는 펠티어 효과와 온도차를 전력으로 변환하는 제백 효과를 이용한다. 열전발전용에 적용되는 상용 열전모듈의 경우, 열전소자의 접합부의 수는 수십 개 이상이다. 따라서 단 한 개의 접합 불량 열전소자가 모듈 전체의 열전성능에 큰 영향을 미친다. 현재 상용화 된 Bi-Te계 열전 모듈은 Bi-Te의 Te와 Sn계 솔더의 주성분인 Sn이 $250^{\circ}C$ 부근에서 취성의 Sn-Te계 금속 화합물을 형성한다고 알려져 있다. 이 때 생성된 Sn-Te 화합물은 열전모듈의 접합강도를 약화시키고 이로 인해 열전모듈의 접합 신뢰성을 크게 저하 시킬 수 있다. 이를 해결하기 위해 솔더와 소자 사이에 확산방지층이 적용되고 있으며, 이 중에서 니켈합금이 가장 널리 적용되고 있다. 니켈층을 형성시키는 방법 중에서, 무전해 도금법은 간단하게 열전소자 표면 위에 도금 층을 균일한 두께로 만들어 낼 수 있다. 하지만, 니켈 도금층과 Bi-Te 소자 간에 화학적 결함이 존재하지 않기 때문에, 무전해 니켈 도금층의 밀착성이 떨어진다. 이 때. 소자 표면에 거칠기 효과(anchor effect)를 부여하기 위해 물리적 샌딩법을 사용하는데 이 방법의 경우 소자에 크랙 같은 손상을 미쳐 열전모듈의 신뢰성 저하를 가져온다. 그러므로 거칠기 효과를 부여하면서 소자에 손상을 최소화하는 습식 식각법을 개발하여 Bi-Te계 열전소자의 표면 조도를 조절하고 무전해 Ni-P 도금을 실시하였다. 그리고 열처리 유무에 따른 열전모듈의 접합강도를 측정하였으며, 제작한 열전 모듈의 접합부 및 파단부의 계면 분석하여 무전해 Ni-P도금을 위한 습식식각법(wet etching법)에 대하여 검토하였다. N-type은 질산과 구연산의 혼합수용액에, P-type은 왕수에 습식 식각처리를 해서 적당히 표면 조도를 조절한 후에 EPMA로 분석을 해본 결과 니켈 도금층과 Bi-Te 소자 간에 anchor effect가 부여 된 것을 확인했다. 습식 식각에 의해서 제조된 열전모듈의 접합강도는 종래의 알루미나 샌딩법으로 제조한 열전모듈 보다 높은 접합강도를 나타내었다.

• Journal of Convergence Society for SMB
• /
• v.5 no.2
• /
• pp.15-20
• /
• 2015

Recently, as smart phone technology is developing, wearable devices is also accelerating. But, the wearable device is necessary to operated for a long time with a small electric power because werable device is made compact. In this paper, we design and implement efficient lithium polymer battery model suitable to miniaturized wearable device in oder to maximize ease of use. The proposed model is characterized by a compact size of the battery by applying a thermal element and a light-weight battery. Also, proposed model gives greatly improve the life of wearable devices because it uses a method using the characteristics of the Peltier device using the temperature difference between the room temperature and body temperature of a person to generate power for charging. In particular, the proposed model can be used for the wearable device, as well as auxiliary charging of the smart phone.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.9
• /
• pp.1-6
• /
• 2019

Preterm children require a controlled environment that is as close as possible to that inside the womb. Incubators are well equipped to fulfill this requirement; however, they are cumbersome and expensive, thereby restricting their portability and availability in less developed and rural areas. This research comprises the development and system validation of a portable incubator. The system consists of a collapsible baby enclosure that can be stowed inside the system base when not in use. The enclosure is made from acrylic such that it is easy to clean and allows unhindered visual observation of the occupant while being robust enough to withstand transit conditions. The system can be powered either by a mains supply or a 12-VDC automobile power supply. Additionally, it has an onboard battery to ensure a continuous supply during transit. A Peltier plate controlled using a microcontroller ensures the desired enclosure temperature irrespective of the ambient temperature. Built-in sensor probes can measure the skin temperature, pulse rate, blood oxygenation level, and ECG of the infant and display them on the system screen. The system function is validated by testing its peak power consumption and the heating and cooling performances of the environment control system.

• Journal of Appropriate Technology
• /
• v.6 no.2
• /
• pp.94-102
• /
• 2020

Renewable energy (RE) is essential to comprise sustainable societies, especially, in rural villages of developing countries. Furthermore, application of off-grid RE systems to health care can improve the quality of life. In this research, a RE-based vaccination supply management system was constructed to enlarge the cold-chain in developing countries for the safe storage and delivery of vaccines. The system was comprised of the construction of RE plants and development of vaccine carriers. RE plants were constructed and connected to health posts in local villages. The cooling mechanism of vaccine carriers was improved and monitoring devices were installed. The effect of the system on vaccine cold-chain was evaluated from the field test and topographical analysis in the southern village of Nepal. RE plants were normally operated for the vaccine refrigerator in the health post. The modified vaccine carriers had a longer operation time and better temperature control via monitoring and RE-based recharging functionality. The topographical analysis estimated that the system can cover larger region. The system prototype showed great potential regarding the possibility of a sustainable and enlarged cold-chain. Thus, RE-based vaccine supply management is expected to facilitate vaccine availability while minimizing waste in the supply chain.