High-precision low-cost temperature controller

A thermal cycler is used to amplify segments of DNA using the polymerase chain reaction (PCR). It is an instrument that requires precise temperature control and rapid temperature changes for certain experimental protocols. However, the commercial thermal cyclers are still bulky, expensive and limited for laboratory use only. As such it is difficult for on-site molecular screening and diagnostics. In this work, a portable and low cost thermal cycler was designed and developed. The thermal cycler block was designed to fit six microcentrifuge tubes. A Proportional-Integral temperature controller was used to control the thermal cycler block temperature. The results showed that the maximum temperature ramp rate of the developed thermal cycler was 5.5 °C/s. The proportional gain (Kp) and integral gain (Ki) of the PI controller were 15 A/V and 1.8 A/Vs respectively. Finally, the developed thermal cycler successfully amplified six DNA samples at the expected molecular weight of 150 base pair. It has been validated using the Eppendorf Mastercycler nexus gradient system and gel electrophoresis analysis

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Temperature Cycle Measurement System Based on Single Chip Computer

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.428-429.487 ◽

2010 ◽

Vol 428-429 ◽

pp. 487-492

Author(s):

Xi Yin ◽

Xiao Jun Wang ◽

Yong Que Xie

Keyword(s):

High Precision ◽

Measurement System ◽

Low Cost ◽

Temperature Cycle ◽

Engineering Practice ◽

Lead Wire ◽

Single Chip ◽

Piecewise Linearization ◽

Single Chip Computer ◽

Precision Temperature

This thesis introduces a low cost and high precision temperature cycle measurement system with adoption of PT100 as temperature sensor, with single chip computer as the core. The method of sub-three-wire connection is proposed for engineering practice, then, can eliminate the effects of lead wire resistance and simplify the external cable connection. We discuss and research circuit component selection, circuit design, improving system reliability, and a software method of piecewise linearization process is adopted, thus we ensure exact and reliable measure and the system characteristic of low cost and high precision.

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Design of Automatic Measurement System of Lithium Battery Electrochemical Impedance Spectroscopy Based on Microcomputer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.241-244.259 ◽

2012 ◽

Vol 241-244 ◽

pp. 259-264 ◽

Cited By ~ 1

Author(s):

Wang Li ◽

Gen Wang Liu ◽

Fu He Yang

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

High Precision ◽

Measurement System ◽

Lithium Battery ◽

Electrochemical Impedance ◽

Low Cost ◽

Automatic Measurement ◽

Response Curves ◽

High Level

A system of miniaturized lithium battery electrochemical impedance spectroscopy (EIS) measurement is designed with high precision impedance converter chip AD5933 as its core. The measurement range of the system is from 0.010Hz to 100 KHz. Meanwhile, by using a high-level programming language of C#, an interface is developed which can real-time graphic display of EIS information. Through measurement and analysis of two types of impedance, the results show that detection precision of the system is less than 3.5%. Finally, amplitude-frequency response curves and Nyquist plots of HL-18650 M lithium battery at different state of charge (SOC) levels are measured. Compared with lithium battery EIS measurement system by traditional division, this system has the outstanding advantages of small size, high level of integration, low cost, simple operation and high precision. It is helpful to the mass production and application of lithium battery EIS measurement system.

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