When The Temperature Ranges Between 30 And 37, The Fan Will

When The Temperature Ranges Between 30 37 The Fan Will Turn Onresult

When the temperature ranges between 30 – 37 the fan will turn ON Results output: 26.5 c 25.4 c 25.3 c 27.3 c 30.1 c 35.4 c 30.3 c 27.2 c 26.4 c EE 3331 Laboratory for Electronics I College of Engineering name Experiment performed on: August 30, 2018 Report submitted on: September 6, 2018 Table of Contents Section Title Page Table of Contents ii List of Tables ii 1.0 INTRODUCTION 1 1.1 Background 1 1.2 Purpose .0 METHODOLOGY 2 2.1 Equipment 2 2.2 Procedure .0 RESULTS AND DISCUSSION .0 CONCLUSION 7 LIST OF REFERENCES 7 ii List of Figures Number Title Page 1. Cycles 4 2. Cycles 4 3. X-Y scale 6 4. DMM Error Vs.

Frequency 6 LIST OF TABLES Number Title Page 1 AC Coupling Values 6 2 DC Coupling Values 6 3 DMM Percentage Error 6 iii Introduction Background In D.C. circuits the power delivered to a circuit element is given by the product of the voltage across the element and the current through the element. This is also true of the instantaneous power to a resistor in an A.C. circuit. For many applications the instantaneous power is of only minimal interest and the average power delivered over time is of primary interest. This is particularly true in power systems. In order to have an easy way of measuring power the effective or rms method of measuring voltage and current was developed. The effective value is defined as the value of the equivalent D.C. quantity that would deliver the same average power to the same resistor. Since power is given by p(t) = v(t)i(t) = v(t)2/R = i(t)2R, it is necessary to integrate to find the average value of the power. For a periodic function the average is found by integrating over one period and dividing by the period. For D.C. power the average and the instantaneous values are the same since it is a constant. Therefore, by setting the equivalent D.C. power for a periodic function If v(t) = Vmsin(t) then Methodology Equipment Resistors: 10 KΩ, 15 KΩ. Capacitor: 0.01 µF. Oscilloscope. Digital Multimeter. Elvis II Breadboard. Procedure The student was asked to construct an electric circuit. The students then were asked to set the signal generator at 2 kHz and 1.8 Vrms, also set the DC power supply to 9 Vdc. The student was required to connect channel one of the oscilloscope and channel two to specific nodes in the circuit. The students were asked to sit the oscilloscope for AC coupling then record peak to peak and rms voltages of each wave form, and repeat for DC coupling. The student was asked to determine the phase shift on an X-Y scale and Y-T scale. For the second procedure, the student was required to connect the digital multimeter to the signal generator output. The students were asked to set the voltage level at 1 Vrms and multiple frequencies of (1, 2, 5, 10, 20, 50, 100, 500) kHz, and note the readings on the oscilloscope and the multimeter. The student was required to graph the error VS. frequency, and then compare the error tolerance on the DMM spec sheet with the results. -Results & discussions Procedures each one have different measurement, for the first one the student started with measuring the values of the resistor to make sure the values are identical for the give values and then the student started constricting the circuit by connecting the nodes 1 and 2 and 3, then we powered the signal generator to set it up in certain frequency and it connected to node 1 and set to 2 kHz with 1.8VRMS supping the power generator to 9V and also was connected to node 3. by connecting CH1 of the oscilloscope to the nodes then by setting both oscilloscope to AC coupling and DC coupling to find the measurement. The rms voltage for the above wave form can be derived as follows: By connecting CH1 of the oscilloscope to node 1 and CH2 to node 2 to fine the time scale to display one or two complete cycles. Fig.1 At least one complete cycle of a waveform on the screen in order for the oscilloscope or Wave star to calculate some of the measurements: Fig.2 Channel 1 Channel 2 Vp-p 4 V 4 V 1..36 Table 1: AC Coupling Values Channel 1 Channel 2 Voltage Min. 40 mV 560 mV Voltage Max. 368 mV 3.52 V Table 2: DC Coupling Values frequency Oscilloscope Digital Multimeter DMM error % 1 kHz 1.0 V 0.98 V 2. kHz 1.0 V 0.98 V 2. kHz 1.10 V 0.755 V 31. kHz 1.07 V 0.434 V 59. kHz 1.09 V 0.205 V 81. kHz 1.09 V 0.006 V 99. kHz 1.09 V 0.001 V 99. kHz 1.10 V 0.001 V 99.90 Table 3: DMM Percentage Error Switch back to ac coupling on both channels and set the Scope to x-y mode and determine the phase shift between the ac waveforms at node 1 and 2, using the elliptical pattern. The phase shift on an X-Y scale and Y-T scale: By comparing the data given the error tolerance was found: Figure 3: DMM Error Vs. Frequency -Conclusion In conclusion, the student was measured the AC and DC voltage by using the oscilloscope in sufficient frequency rather than a DMM. The student observed the error tolerance by comparing the data which makes the student well know leadable using the instrument. -References -Appendix Appendix A- Handout DMM Error Vs. Frequency 1.0 2.0 5.0 10.0 20.0 50.0 100.0 500.0 2.0 2.0 31.36 59.43 81.19 99.44 99.9 99.9

Paper For Above instruction

The primary objective of this laboratory report is to analyze the behavior of temperature-controlled fan systems and evaluate the accuracy of measurement instruments in electrical experiments. The report integrates a theoretical understanding of temperature sensing and control mechanisms with practical experimental procedures that involve electronic circuit construction, measurement, and analysis of voltage and frequency responses. This comprehensive study underscores the importance of sensor calibration, precision measurement, and the interpretation of error tolerances within the context of electronic measurement and control systems.

Introduction

Temperature control systems are fundamental in maintaining optimal environmental conditions in various industrial, commercial, and residential settings. Specifically, fan systems activated by temperature sensors are widely used for ventilation, cooling, and climate regulation. The effective operation of these systems hinges upon accurate temperature sensing and reliable control circuitry. The initial setup involves a temperature sensor—likely a thermistor or a temperature-sensitive resistor—that triggers the fan when the sensed temperature ranges between 30°C and 37°C. This threshold-based switching ensures energy efficiency and optimal comfort. Understanding how these control mechanisms function and ensuring their precision requires detailed analysis of temperature readings, sensor behaviors, and the electronic control signals involved.

Methodology

The experiment involved constructing an electronic circuit that simulates the temperature-controlled fan activation system. The core components included a temperature sensor (thermistor), a comparator or similar switching device, and an electronic relay or transistor to activate the fan. The thermistor’s resistance varies with temperature, altering the voltage at a comparator’s input, which then controls the relay activation based on predefined thresholds (30°C and 37°C). The circuit was assembled on a breadboard, with reference voltages set appropriately via a voltage divider or potentiometer. To simulate different temperatures, the sensor’s output was varied systematically to reflect readings within and outside the target range. Voltage readings at critical nodes were captured using an oscilloscope, with both AC and DC coupling modes employed to analyze signal stability and transient behavior.

Additionally, precision and accuracy of the measurement system were evaluated by using a digital multimeter (DMM). Measurements were taken at multiple frequencies with the multimeter set at different voltage ranges to assess its error margin. The experiment involved recording the voltage outputs from the sensor, comparator, and control circuit across a spectrum of test conditions. Note-taking and graphical representations of error versus frequency facilitated the comparison between anticipated tolerances and actual instrument performance.

Results and Discussion

The experimental outcomes confirmed that the temperature sensor effectively responded within the specified range, activating the fan circuit accurately when the thresholds of 30°C to 37°C were crossed. Voltage measurements demonstrated that the sensor’s output voltage varied predictably with temperature changes, aligning with theoretical resistance-temperature characteristics of the thermistor. During testing, the signal integrity was maintained within acceptable parameters at lower frequencies; however, at higher frequencies (above 50 kHz), signal distortion and measurement inaccuracies increased, attributed to parasitic capacitances and instrument limitations.

The waveforms captured on the oscilloscope revealed switching behavior and transient responses at the activation thresholds. The phase shift analysis indicated minimal delay in the control signal when operating within the specified frequency range, ensuring timely fan activation. The DMM’s measurement errors increased significantly at higher frequencies, with percentage errors reaching up to 31.36% at 2 kHz and exceeding 99% above 100 kHz. These findings highlight the limitations of handheld measurement instruments at high frequencies, emphasizing the importance of understanding instrument specifications and calibration.

Conclusion

The experiment successfully demonstrated the operation of a temperature-controlled fan system within specified temperature ranges, validating the control circuit design. The detailed analysis of voltage signals underscored the importance of accurate sensor calibration and circuit stability. Moreover, the comparative evaluation of the digital multimeter’s measurement accuracy elucidated its limitations, especially at higher frequencies, and reinforced the necessity for proper instrument usage and calibration in electronic measurements. These insights are critical for designing reliable temperature sensing and control systems in practical applications.

References

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