Project Structure In General: You Will Have One Other Classm

Project Structurein General You Will Have One Other Classmate In You

Design and simulate an instrumentation circuit that measures air temperature and provides an alert when the temperature exceeds specified limits. Collaborate with a teammate to select different temperature thresholds, develop a test plan, and validate each other's designs. Use a common sensor and thermistor, and incorporate an amplification circuit with an operational amplifier Wheatstone bridge. Develop a comprehensive report including a conceptual design, calculations, schematic, test results, troubleshooting manual, and team reflection. Submit individual reports and Multisim files, demonstrating effective teamwork and technical understanding.

Paper For Above instruction

The project entails designing a temperature alarm system capable of measuring air temperature and alerting users when temperatures surpass or fall below predefined thresholds. Collaboration and communication with a teammate are integral, as each member should select distinct temperature limits and design a circuit accordingly. The system's core functions include sensing temperature via a thermistor, amplifying the signal with an operational amplifier Wheatstone bridge, and triggering visual alerts—red or green LEDs—based on temperature ranges. The project emphasizes practical implementation, simulation, testing, troubleshooting, and comprehensive documentation.

Given the critical role of accurate.temperature measurement in safety and automation, the choice of sensor and circuit design is paramount. Both team members will use the same thermistor model, preferred after reviewing datasheets to ensure appropriate responsiveness and stability in the circuit. The thermistor's characteristics directly influence the circuit design, particularly in the amplification and threshold detection stages. The operational amplifier Wheatstone bridge is advantageous because it offers precise, balanced measurement with high sensitivity, especially suitable for detecting minute resistance changes in thermistors, leading to more accurate temperature readings.

The block diagram of the system (Figure 1 in the prompt) demonstrates the sequential flow from sensing to alerting. The first stage involves the thermistor sensing ambient temperature, with its resistance varying according to temperature. The second stage—an amplification circuit—uses an operational amplifier configured as a Wheatstone bridge to convert resistive changes into a voltage signal. This signal is then processed to determine whether the temperature is within, below, or above the set limits. Appropriate threshold detection logic turns the LEDs on or off to indicate the current temperature status. These stages work together to provide a reliable and clear indicator of temperature conditions.

In the design methodology, a comprehensive set of calculations should be included. For instance, selecting the thermistor requires choosing a sensing range compatible with the specified temperature limits (e.g., 40°F to 110°F). Using the datasheet, the resistance at these temperatures is identified. The Wheatstone bridge configuration is then designed to convert resistance variation into an measurable voltage, followed by calculation of amplification gain and threshold voltages for LEDs activation. These calculations are based on standard circuit analysis principles, ensuring component choices are accessible and cost-effective.

The final schematic in Multisim should reflect accurate component values derived from the calculations. The parts list must include the thermistor, operational amplifier (e.g., LM358), resistors, diodes, LEDs, power supply, and any additional passive components needed for stability and filtering. Simulation results should demonstrate the circuit's functionality across the temperature spectrum, with clear indication of when each LED activates. Characterization involves testing the circuit at temperatures below, within, and above the threshold range, ensuring the LEDs respond correctly.

Testing involves creating a detailed plan, applying known temperature inputs—either via simulation or physical environment—and recording the circuit's response. The validation process verifies whether the circuit meets specifications: LEDs should turn on when temperature exceeds limits or stay green when within the normal range. The results must be supported by descriptive analysis and screenshots of the simulation outputs, illustrating the circuit’s performance during different test scenarios.

The troubleshooting manual addresses a potential problem, such as the LEDs not activating correctly or inconsistent readings. For example, if the red LED fails to turn on above the upper limit, step-by-step troubleshooting guidelines should be provided, starting from checking power supplies, sensor connections, and component integrity, to verifying the threshold detection circuitry. The process aims to enable technicians to identify and rectify the issue efficiently, excluding power supply problems as per project constraints.

During the project, challenges such as component selection, circuit stability, or achieving desired sensitivity might arise. Overcoming these involves iterative testing, simulation adjustments, and research into alternative components or configurations. Team interactions facilitated through Blackboard and in-person meetings should be documented, emphasizing collaboration, idea exchange, and mutual support during problem-solving.

In conclusion, this project amalgamates sensor selection, circuit design, simulation, testing, troubleshooting, and teamwork. It underscores the importance of systematic planning, precise calculations, practical implementation, and effective communication in engineering projects. Final submission includes a detailed report, schematics, simulation data, testing validation, troubleshooting procedures, team reflections, and proper citations, ensuring a comprehensive demonstration of technical competency and collaborative effort.

References

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• Electronics Tutorials. (n.d.). Bridge Circuits and Operational Amplifiers. https://www.electronics-tutorials.ws
• National Instruments. (2020). Using Wheatstone Bridges for Precise Resistance Measurements. NI.com.
• Hamberg, L. (2018). Practical Temperature Sensor Selection and Calibration. Journal of Sensor Technology.
• Texas Instruments. (n.d.). Operational Amplifier datasheets and application notes. TI.com.