Rectification & Power Supplies
Master AC to DC conversion: half-wave rectification, full-wave center-tapped and bridge rectifiers, capacitor smoothing filters, ripple factor calculation, and regulated DC power supplies.
Marking a lesson complete represents finishing your study of the topic; it does not denote tested mastery.
Learning Objectives
- Analyze half-wave and full-wave bridge rectifier circuits, tracing current conduction paths during both AC half-cycles.
- Determine output ripple frequencies: f_out = f_in for half-wave and f_out = 2 f_in for full-wave rectifiers.
- Explain capacitor filter smoothing action and calculate peak-to-peak ripple voltage V_r = I_L / (f · C).
Core Theory & Concepts
Almost all solid-state electronic devices require smooth, steady direct current (DC) operating voltages. A power supply converts high-voltage alternating mains current (AC) into low-voltage stable DC through four sequential stages: step-down transformation, rectification, capacitive smoothing, and Zener voltage regulation.
Full-Wave Bridge Output Peak
In a bridge rectifier, current conducts through two forward-biased diodes in series during each half cycle, dropping 2 * 0.7 V = 1.4 V from secondary peak.
Peak-to-Peak Ripple Voltage
With a smoothing capacitor C discharging into load current I_L over period T = 1/f_r: V_r = I_L / (f_r · C).
Common Misconceptions
A rectifier output with a capacitor produces perfectly flat DC with zero ripple.
Syllabus Topic Outline
- 1Half-wave rectifier: circuit, single diode conduction, efficiency, and waveforms
- 2Full-wave bridge rectifier: 4-diode Graetz topology, conduction cycles, PIV
- 3Reservoir capacitor filtering: charging and discharging curves
- 4Peak-to-peak ripple voltage formula: V_r = I_L / (f_r · C)
- 5Complete regulated DC power supply architecture: Transformer → Rectifier → Filter → Zener Regulator