🔍 Key Concepts

• Identify each section of the circuit (A: transformer, B: rectifier, C: filter, D: regulator/load) and what it does to the waveform shape. • Compare full-wave rectified, filtered DC with ripple, and regulated DC waveforms (E, F, G, H). • Understand how a series pass transistor with a Zener diode (Q1 and CR1) affects voltage ripple at the output test point.

💭 Think About

• Trace what the waveform looks like at TP3 right after the diodes, then imagine how L1 and C1 at TP4 modify that waveform, and finally how Q1/CR1/RL at TP5 modify it again. • Ask yourself: Does each successive stage increase, decrease, or leave unchanged the amount of ripple on the DC? Which of the given waveforms best represents the final stage after regulation? • Consider whether TP5 is before or after the main filtering/regulating components and how that placement changes what you would see on an oscilloscope referenced to ground.

✅ Before You Answer

• Be sure which test point (TP3, TP4, TP5) corresponds to rectified but unfiltered, filtered, and regulated DC. • Confirm that Q1 and CR1 form a voltage regulator section, which should have less ripple than the raw rectified output. • Match the number of pulses per AC cycle and the amount of ripple versus average DC level in each candidate waveform (E, F, G, H) to the expected behavior at the very end of the power supply.