[Radiologic Physics] Ep 12 – Rectification

This episode covers rectification — the process of converting alternating current (AC) to direct current (DC) in the x-ray circuit. Prof. Arya explains why unrectified AC would allow reverse electron flow from anode to cathode during the negative half-cycle, risking tube damage and wasted exposure. The episode examines both early vacuum valve tube rectifiers and modern solid-state diodes, tracing the p-n junction mechanism that permits current to flow in only one direction, and compares half-wave and full-wave rectification in terms of pulse output, rectifier count, and clinical efficiency. The second half explores single-phase, three-phase, and high-frequency power supplies — comparing 6-pulse and 12-pulse configurations, voltage ripple percentages, and their effect on x-ray output and image quality. The high-frequency generator's inverter circuit is detailed step by step, highlighting its advantages in size, efficiency, and near-constant potential voltage. The episode closes with practical methods for detecting rectification failure — the spinning top test, synchronous spinning top, and oscilloscope. This episode aligns with the Equipment Operation and Quality Assurance content category — Radiographic Equipment subcategory — of the ARRT Radiography Examination Content Specifications. Audio content is adapted from original instructional material developed by Professor Sanjay Arya, M.S., R.T.(R)(MR) for radiologic technology education. Part of the Radiologic Physics series — Quantum Imaging Lab. © 2026 Quantum Imaging Lab. All rights reserved.