Low Cost, Open-Loop Temperature Controller for MEMS and Modular Microfluidics Applications

2011 ◽  
Author(s):  
Brooks B. Lowrey ◽  
Christopher R. Brown ◽  
Daniel S. Park ◽  
Michael C. Murphy
Keyword(s):  
Low Cost ◽  
Open Loop ◽  
Thermal Reactor ◽  
Temperature Controller ◽  
Thermally Responsive ◽  
Channel Temperature ◽  
Temperature Boundary ◽  
In Series ◽  
Commercial Off The Shelf ◽  
Model C

A commercially manufactured thermostat (Model C Thermostat, Portage Electronic Products Inc., North Canton, OH) was employed as a precision MEMS temperature controller for a simulated continuous flow thermal reactor, with three temperature zones to mimic a polymerase chain reaction (CFPCR) device but different temperature set points to allow use of off-the-shelf controllers and thermally-responsive fluids. The ability of the commercial thermostats to maintain the temperatures within given tolerance bands in the thermal reactor was investigated. The factory supplied and calibrated thermostats were actuated by trimetallic strips, and supplied in a normally-closed configuration. Each thermostat was arranged in series with a 28 VDC power supply, a Kapton heater, and an aluminum thermal block to establish a constant temperature boundary condition for each temperature zone. Calibration temperatures for each thermostat reflected the three temperature set points of the simulated PCR device in the testing apparatus. Temperatures were collected by fixing Type K thermocouples in the fluidic channels of the simulated PCR device, and recording the temperature over time. The commercial, off-the-shelf, open-loop controllers successfully maintained ±1°C tolerance bands within each thermal zone. The ±1°C variation in the channel temperature was caused by the chatter due to the switching of the thermostat.

Open Loop Speed Control Of Brushless DC Motor Using Low Cost Arduino UNO Processor

2016 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Potnuru Devendra ◽  
Mary K. Alice ◽  
Ch. Sai Babu ◽  
◽  
◽  
...  
Keyword(s):  
Low Cost ◽  
Speed Control ◽  
Dc Motor ◽  
Open Loop ◽  
Brushless Dc Motor ◽  
Brushless Dc ◽  
Arduino Uno

scholarly journals Radiation testing of low cost, commercial off the shelf microcontroller board

2021 ◽  
Author(s):  
Tomas Fried ◽  
Antonio Di Buono ◽  
David Cheneler ◽  
Neil Cockbain ◽  
Jonathan M. Dodds ◽  
...  
Keyword(s):  
Low Cost ◽  
Radiation Testing ◽  
Commercial Off The Shelf

Low-cost programmed oven temperature controller

1982 ◽  
Vol 59 (4) ◽  
pp. 338 ◽  
Author(s):  
Gerald D. Clubine
Keyword(s):  
Low Cost ◽  
Temperature Controller

A multi-channel temperature controller for diffusion furnace

1980 ◽  
Vol 6 (5) ◽  
pp. 325-329
Author(s):  
W. Lobodzinski ◽  
M. Orzylowski ◽  
Z. Rudolf
Keyword(s):  
Temperature Controller ◽  
Channel Temperature

scholarly journals Development of a low-cost X-band meteorological radar

2021 ◽  
Author(s):  
Jan Hrach
Keyword(s):  
Material Selection ◽  
Low Cost ◽  
Technology Selection ◽  
Advantages And Disadvantages ◽  
Radar Network ◽  
X Band ◽  
Spatially Distributed ◽  
Commercial Off The Shelf ◽  
Slotted Waveguide ◽  
Small Team

<p>We have undertaken a journey to develop a small X-band radar based on widely available commercial off-the-shelf (COTS) components. We have evaluated various radar transmitters, antenna and radome designs and sizes and we are currently operating the second-largest radar network in Europe, spanning 5 countries and consisting of 30 radars.</p><p>The final solution can be deployed by a small team in two days and operated without supervision with negligible maintenance and recurring costs. With approximately 120 kilometers of effective range and high refresh rate, it might be a good fit as an early warning radar, for areas with no current radar coverage or to fill gaps in larger networks; however, due to some limitations of the X band, namely higher attenuation in spatially distributed rain, it may not be a replacement of long-range observation radars.</p><p>In this work, we present an overview of our undertakings, technical solutions we have chosen and problems we have encountered. First, we cover transmitter technology selection, and discuss advantages and disadvantages of currently available magnetron and solid-state transmitters. Then we show the evolution of our antenna design, from 1-dimensional slotted waveguide to parabolic antennas with tapered beam. </p><p>With large parabolic antennas, another problem arises: the mechanics of the radar cannot cope with the additional weight and angular momentum, thus we had to develop various mechanical supports and a custom rotator. This rotator can also tilt the antenna, effectively adding volumetric scanning; the tilting is also needed to cope with non-ideal radar locations, where the horizon is partially obscured, which are unfortunately common for a radar network with limited budget. Finally, we discuss design and material selection of our custom radomes, and present an overall experience with everyday running and maintaining the network.</p>

scholarly journals Design and development of polymerase chain reaction thermal cycler using proportional-integral temperature controller

2018 ◽  
Vol 14 (2) ◽  
pp. 213-218
Author(s):  
Chong Kim Soon ◽  
Nawoor Anusha Devi ◽  
Kok Beng Gan ◽  
Sue-Mian Then
Keyword(s):  
Polymerase Chain Reaction ◽  
Low Cost ◽  
Maximum Temperature ◽  
Gradient System ◽  
Chain Reaction ◽  
Temperature Controller ◽  
Proportional Integral ◽  
Integral Temperature ◽  
Polymerase Chain ◽  
Thermal Cycler

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

scholarly journals Propagation of cortical activity via open-loop intrathalamic architectures: a computational analysis

2019 ◽  
Author(s):  
Jeffrey W. Brown ◽  
Aynaz Taheri ◽  
Robert V. Kenyon ◽  
Tanya Berger-Wolf ◽  
Daniel A. Llano
Keyword(s):  
Closed Loop ◽  
Neural Model ◽  
Signal Propagation ◽  
Open Loop ◽  
Thalamic Reticular Nucleus ◽  
Oscillatory Activity ◽  
Reticular Nucleus ◽  
Dorsal Thalamus ◽  
In Series ◽  
Intracortical Connectivity

AbstractPropagation of signals across the cerebral cortex is a core component of many cognitive processes and is generally thought to be mediated by direct intracortical connectivity. The thalamus, by contrast, is considered to be devoid of internal connections and organized as a collection of parallel inputs to the cortex. Here, we provide evidence that “open-loop” intrathalamic connections involving the thalamic reticular nucleus (TRN) can support propagation of oscillatory activity across the cortex. Recent studies support the existence of open-loop thalamo-reticulo-thalamic (TC-TRN-TC) synaptic motifs in addition to traditional closed-loop architectures. We hypothesized that open-loop structural modules, when connected in series, might underlie thalamic and, therefore cortical, signal propagation. Using a supercomputing platform to simulate thousands of permutations of a thalamo-reticular-cortical network and allowing select synapses to vary both by class and individually, we evaluated the relative capacities of closed- and open-loop TC-TRN-TC synaptic configurations to support both propagation and oscillation. We observed that 1) signal propagation was best supported in networks possessing strong open-loop TC-TRN-TC connectivity; 2) intrareticular synapses were neither primary substrates of propagation nor oscillation; and 3) heterogeneous synaptic networks supported more robust propagation of oscillation than their homogeneous counterparts. These findings suggest that open-loop heterogeneous intrathalamic architectures complement direct intracortical connectivity to facilitate cortical signal propagation.Significance StatementInteractions between the dorsal thalamus and thalamic reticular nucleus (TRN) are speculated to contribute to phenomena such as arousal, attention, sleep, and seizures. Despite the importance of the TRN, the synaptic microarchitectures forming the basis for dorsal thalamus-TRN interactions are not fully understood. The computational neural model we present incorporates “open-loop” thalamo-reticular-thalamic (TC-TRN-TC) synaptic motifs, which have been experimentally observed. We elucidate how open-loop motifs possess the capacity to shape the propagative properties of signals intrinsic to the thalamus and evaluate the wave dynamics they support relative to closed-loop TC-TRN-TC pathways and intrareticular synaptic connections. Our model also generates predictions regarding how different spatial distributions of reticulothalamic and intrareticular synapses affect these signaling properties.

scholarly journals AUTOMATED EXTRACTION OF SATELLITE TRAILS FROM WIDE ANGLE CCD IMAGERY

2019 ◽  
Vol 51 ◽  
pp. 150-158
Author(s):  
G. Privett ◽  
S. George ◽  
W. Feline ◽  
A. Ash
Keyword(s):  
Optical Sensors ◽  
Security Policy ◽  
Situational Awareness ◽  
Low Cost ◽  
Automated Analysis ◽  
Wide Angle ◽  
National Space ◽  
The United Kingdom ◽  
Commercial Off The Shelf ◽  
Sovereign Territory

The current UK’s National Space and Security Policy states that the identification of potential on-orbit collisions and warning of re-entries over UK sovereign territory is of high importance, driving requirements for indigenous Space Situational Awareness (SSA) systems capable of delivering these products. The UK’s Defence Science and Technology Laboratory (Dstl) is examining options for the creation of a distributed network of longitudinally distributed, low cost commercial–off-the-shelf electro-optical sensors to support survey work and catalogue maintenance. To effectively exploit this, a robust data handling system is required to autonomously detect satellite trails in a manner that can handle variable target intensities, periodicities and rates of apparent motion, as well as meteors and aircraft. Data captured during the United Kingdom/New Zealand Automated Transfer Vehicle-5 (ATV-5) deorbit observation trial have been employed to inform the development of a prototype processing pipeline for autonomous on-site processing. The approach taken employs pre-existing and documented tools such as Astrometry.NET and DAOPHOT from the astronomical community, together with image processing and orbit determination software developed in-house by Dstl. Some preliminary results from the automated analysis of data collected from wide angle sensors are described, together with an appraisal of the limitations of the proposed system and our plans for future development

Load cells calibration with a low cost data acquisition system

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Pedro Leineker Ochoski Machado ◽  
Luis Vitorio Gulineli Fachini ◽  
Vitor Otávio Ochoski Machado ◽  
Romeu Miqueias Szmoski ◽  
Thiago Antonini Alves
Keyword(s):  
Data Acquisition ◽  
Calibration Curve ◽  
Applied Load ◽  
Low Cost ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Voltage Variation ◽  
Load Cells ◽  
In Series ◽  
Measurement Uncertainties

In the present work, an experimental analysis was performed to obtain the calibration curve of three load cells connected in series. The control of the load applied on a given component is an important factor in some engineering applications, for example, in cases where it is desired to increase the heat exchange between two surfaces. One of the ways to control the applied load is the use of load cells, which has as its principle of use a strain gauge that has its resistance varied when it undergoes a deformation, thus causing a voltage variation due to the application of load. This study used an ArduinoTM microcontroller as a data acquisition system and blocks with known mass for load application.  In this way it was possible to obtain the calibration curve of the load cells by means of linear regression between the mass of the blocks and the data obtained by the ArduinoTM microcontroller and verify their applicability according to their measurement uncertainties.

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