Lesson 1, Topic 1
In Progress

Rectification

April 11, 2024

Rectification

Learning Objective: Examine rectification.

Rectification is changing AC into DC, so it flows in one direction only. This is done with the use of rectifiers. The rectification process prepares the current for x-ray production by ensuring that it flows in the right direction, in this case, from the filament to the target. There are three ways in which the current is rectified: self-rectification, half-wave rectification, and full-wave rectification. Self-rectification is no longer used.

Half-Wave Rectification

Learning Objective: Examine rectification.

AC travels in copper wire as a sine wave. It moves in a pulsating manner from positive to negative. In half-wave rectification, the negative phase of the electric cycle is completely removed, and a gap remains. The x-rays are turned off during the eliminated (negative) phase. With only the positive phase remaining, the current is “direct” only or DC. The x-rays are pulsating on and off.

Full-Wave Rectification

Learning Objective: Define full-wave rectification.

During full-wave rectification, the current is redirected during the negative half of the electric cycle so that the current will flow in the same direction during the positive and negative halves of the cycle. So, full-wave rectification uses the entire electric cycle for x-ray production. The negative impulses are made positive rather than being eliminated. All modern general-purpose x-ray machines are full-wave rectified. The main advantage of full-wave rectification is that the exposure time can be cut in half because of the doubling in x-ray output compared with half-wave.