scholarly journals Development of Auto Thermal Control Device For Space Air - Conditioning

2021 ◽  
pp. 193-204
Author(s):  
Akinde Olusola Kunle ◽  
Maduako Kingsley Obinna ◽  
Akande, Kunle Akinyinka ◽  
Adeaga Oyetunde Adeoye
Keyword(s):  
Temperature Coefficient ◽  
Room Temperature ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Thermal Control ◽  
Positive Temperature Coefficient ◽  
Control Device ◽  
Thermal Source ◽  
Positive Temperature ◽  
Ntc Thermistor

Auto Thermal Control device is an electronic based device which employs the application of temperature sensors to controlling household appliances without human interference directly. In this work, thermal source is used to regulate electrical fan and room heater depending on ambient temperature. The room heater, which is adjusted to a set temperature, switches ‘ON’ when the temperature of a room is low (cold). While the same is switches ‘OFF’ with increase in the room temperature. This triggers ‘ON’ an electric fan at different speeds, and thus cools the room. A temperature sensor, tthermistor, monitors change in room temperature. Two types of thermistor exists: Positive Temperature Coefficient, PTC. An increasee in the resistance of PTC results in increasee in temperature). In the Negative Temperature Coefficient, NTC; a decreasee in resistance yields to temperature increase. This article explored a NTC thermistor. The design could be a ready product in the market of the developing nation where environmental automation is yet fully deployed.

scholarly journals Response characteristics of a negative temperature coefficient thermistor

2020 ◽  
Vol 1 ◽  
pp. 17-22
Author(s):  
Sunday F. Iyere ◽  
Bernard O. A. Ozigi ◽  
Joseph K. Yeboah
Keyword(s):  
Temperature Coefficient ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Control Device ◽  
Response Curves ◽  
Temperature Changes ◽  
Response Characteristics ◽  
Ntc Thermistor ◽  
And Control ◽  
Measurement And Control

This article focuses on the thermistor as a device that is widely used for temperature measurement and control in most electrical and electronic devices and appliances. The research is based on the type of thermistor used in photocopiers with particular reference to Minolta Bizhub (model-210) photocopier. The resistance and temperature were recorded by the application of conventional heat to deduce the response curves of resistance versus temperature and resistance/time. Results obtained from the characteristics show that the thermistor employed in the photocopier is a negative temperature coefficient (NTC) device. Also, there was a time variation in the response of the thermistor resistance to temperature changes, which indicates that the thermistor under test functions as a temperature control device. The shape of resistance versus temperature curve appeared to be similar to that of a typical NTC thermistor characteristics.

Design for high-performance functional composite thermistor materials by glass/ceramic composing

1999 ◽  
Vol 14 (7) ◽  
pp. 2993-2996 ◽  
Author(s):  
D. J. Wang ◽  
J. Qiu ◽  
Z. L. Gui ◽  
L. T. Li
Keyword(s):  
Temperature Coefficient ◽  
Glass Ceramic ◽  
High Performance ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Functional Composite ◽  
Performance Functional ◽  
Temperature Coefficient Of Resistivity

A negative temperature coefficient–positive temperature coefficient (NTC-PTC) composite thermistor with high performance was designed by glass/ceramic composing. The material exhibited low resistivity and a large negative temperature coefficient of resistivity. The minimum resistivity was the magnitude of 102 Ω cm, and the negative temperature coefficient of resistivity was better than −3% °C−1. The results showed that the large negative temperature coefficient of resistivity was closely related to the glass phase, and the NTC-PTC functional composite material was a kind of grain-boundary–controlled material.

Effect of temperature on the toxicity of S-bioallethrin andcypermethrin to susceptible and kdr-resistant strains of Blattella germanica (L.) (Dictyoptera: Blattellidae)

1987 ◽  
Vol 77 (3) ◽  
pp. 431-435 ◽  
Author(s):  
Jeffrey G. Scott
Keyword(s):  
Temperature Coefficient ◽  
Negative Temperature Coefficient ◽  
Blattella Germanica ◽  
Negative Temperature ◽  
Positive Temperature Coefficient ◽  
Effect Of Temperature ◽  
Positive Temperature ◽  
Pyrethroid Insecticides ◽  
Resistant Strains ◽  
The Difference

AbstractThe toxicity of two pyrethroid insecticides, S-bioallethrin and cypermethrin, was investigated over time at 12, 25 and 31°C in susceptible and kdr resistant strains of Blattella germanica (L.). Both strains showed a negative temperature coefficient (i.e., greater kill with decreasing temperature) for S-bioallethrin. The susceptible strain had a negative temperature coefficient for knockdown, but a positive temperature coefficient for mortality towards cypermethrin. The resistant strain had a negative temperature coefficient towards cypermethrin at all times. Resistance to S-bioallethrin was generally greatest at 25°C initially, although the difference between temperatures and the level of resistance diminished with time. Resistance to cypermethrin was significantly less at 12°C than at 25 or 31°C.

Suppressing the negative temperature coefficient effect of resistance in polymer composites with positive temperature coefficients of resistance by coating with parylene

2020 ◽  
Vol 8 (22) ◽  
pp. 7304-7308 ◽  
Author(s):  
Chihiro Okutani ◽  
Tomoyuki Yokota ◽  
Ryotaro Matsukawa ◽  
Takao Someya
Keyword(s):  
Temperature Coefficient ◽  
Polymer Composites ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Temperature Coefficients ◽  
Ntc Effect

Thin parylene coating suppressed the negative temperature coefficient (NTC) effect of polymer thermistors with a positive temperature coefficient (PTC) while maintaining the PTC characteristics.

scholarly journals Modeling, Characterization and linearization of Negative Temperature Coefficient (NTC) Thermistor and Pressure Sensors

2020 ◽  
Vol 8 (6S) ◽  
pp. 82-88
Keyword(s):  
Temperature Coefficient ◽  
Negative Temperature Coefficient ◽  
Low Cost ◽  
Pressure Sensors ◽  
Negative Temperature ◽  
Positive Temperature Coefficient ◽  
Industrial Applications ◽  
Special Treatment ◽  
Positive Temperature ◽  
Highly Nonlinear

Industrial applications such as air-conditioning, microelectronic, automotive, food processing are automated using various sensor technologies. The sensor technologies could be temperature, pressure and others as well. The negative temperature coefficient (NTC) sensors are the preferred choice due to their stability over their counterpart positive temperature coefficient (PTC) sensors. These sensors are highly nonlinear and need special signal conditioning circuits to use them in all industrial applications. Pressure sensor does need a special treatment while measuring their values for industrial applications. This paper presents the method to model, characterize and linearize NTC and pressure sensors. A low-cost system was built to validate the presented method.

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