EET 2010 Lab Exercise 2 Electronics Principles Half And Full

EET 2010 Lab Exercise 2 Electronics Principleshalf And Full Wave Re

Construct and measure the output of a half wave and a full wave rectifier and the filtered output. In addition, learn to use the Math function on the oscilloscope.

Assemble circuits with specified components and measure voltage waveforms using an oscilloscope. Record maximum, minimum, and ripple voltages, and calculate ripple factors for each configuration. Use the Math function on the oscilloscope to analyze the rectified waveforms. Finally, discuss waveform shapes, the circuit's functionality, and the importance of filtering capacitors, including observations related to removing loads.

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The objective of this laboratory exercise is to understand the operation and characteristics of half-wave and full-wave rectifier circuits, along with the effectiveness of filtering to smooth the rectified output. Rectifiers are essential in converting AC to DC power, fundamental in power supply design. The experiment utilizes several electronic components, including diodes, resistors, and capacitors, combined with measurement tools like a function generator and a digital oscilloscope, to analyze waveforms and performance metrics systematically.

The initial phase involves constructing half-wave and full-wave rectification circuits as per provided schematics. The function generator is set to provide a sinusoidal AC voltage (e.g., V1 = 2.5 V peak, 250 Hz, 0° phase) and connected to the rectifier circuit. Using the oscilloscope, the primary voltage V1 and the output across the resistor load are measured. These waveforms are recorded by capturing screenshots with annotated measured values, including the maximum and minimum voltages of the rectified waveforms. The half-wave rectifier allows current flow during positive half cycles, resulting in a pulsating DC voltage, while the full-wave rectifier conducts during both half cycles, providing a more constant pulsating DC output.

Subsequently, passive filtering is introduced by adding capacitors—10 μF and 100 μF—in parallel with the load resistor. The purpose of the capacitor is to reduce the ripple voltage—the residual AC component superimposed on the DC level—thus producing a smoother DC output. For each capacitor value, the ripple voltage's peak-to-peak amplitude is measured after the circuit stabilizes, and screenshots are saved for documentation. These measurements demonstrate the capacitor's effectiveness, where larger capacitance values generally yield smaller ripple voltages, improving voltage stability.

The ripple factor, an important parameter indicating the quality of rectification and filtering, is calculated for each configuration using the formula: Ripple Factor = (Ripple Voltage) / (DC Output Voltage). These calculations quantify the effectiveness of the filtering process and are crucial in power supply design to ensure voltage regulation and reduce noise.

In the second part of the experiment, the setup is modified to include a subtraction of signals using the oscilloscope's math function. The circuits from a reference figure (Figure 2-2) are assembled with proper grounding and verification by the instructor. The function generator provides V1, and the scope measures node voltages. The scope's math function subtracts the voltage at node 1 from node 3, providing the rectified waveform as seen by the resistor. The maximum, minimum, and ripple voltages of this processed waveform are recorded, offering insight into the actual voltage experienced by the load after rectification and filtering.

Further, the addition of capacitors across this output and subsequent measurement of ripple voltages mirror previous steps, reinforcing the understanding of filtering efficacy. Replacing the 10 μF capacitor with a larger 100 μF capacitor typically results in a significant reduction in ripple voltage, which correlates with theoretical expectations based on capacitor reactance and load conditions.

An optional bonus task involves removing the load and filters to observe the raw rectified waveform with no mitigation. Such an observation reveals that, without filtering, the waveform remains pulsating and highly variable, emphasizing the importance of capacitors in practical power supply applications for producing stable DC voltages.

The discussion elaborates on the observed waveforms, comparing theoretical expectations with experimental results. For half-wave rectification, the waveform shows positive pulses during the positive half cycles, with the negative half cycles suppressed. For full-wave rectification, the waveform exhibits a more continuous series of positive pulses, effectively doubling the frequency of the pulsating voltage, which results in a higher average voltage and lower ripple for given filter capacitance. The role of the capacitor as a smoothing element is emphasized, clarifying how larger capacitors filter out more ripple, but also introduce effects like increased inrush current and potential voltage overshoot.

Finally, the significance of waveform behavior and filtering in real-world applications is discussed. Effective filtering reduces noise and voltage fluctuations, crucial for sensitive electronic devices. The experiment demonstrates that practical considerations such as load conditions, capacitor size, and rectifier type critically influence circuit performance. These insights are foundational for designing reliable power supplies that deliver consistent DC voltage to electronic systems.

References

• Sedra, A. S., & Smith, K. C. (2014). Microelectronic Circuits (7th ed.). Oxford University Press.
• Boylestad, R., & Nashelsky, L. (2009). Electronic Devices and Circuit Theory (11th ed.). Prentice Hall.
• Rashid, M. H. (2013). Power Electronics: Circuits, Devices & Applications (4th ed.). Pearson.
• Paul, C. R. (2008). Introduction to Electronic Circuit Design. Wiley.
• [Online Source] Principles of Rectification and Filtering. Electronics Tutorials. https://www.electronics-tutorials.ws/power/rectifiers.html
• [Online Source] Oscilloscope Math Functions. Tektronix. https://www.tek.com/support/software/oscilloscope-math-functions
• Kaminow, I. P., & Burrus, C. A. (2012). Optical Fiber Communications: Principles and Practice. Pearson.
• Malvino, A. P., & Leach, D. P. (2007). Digital Principles and Applications (7th ed.). McGraw-Hill.
• Horowitz, P., & Hill, W. (2015). The Art of Electronics (3rd ed.). Cambridge University Press.
• Gonzalez, R. C., & Woods, R. E. (2018). Digital Image Processing (4th ed.). Pearson.