X Ray Imaging System Bushong Chapter 8

Front 1

Three main components of xray imaging system

Back 1

xray tube
operating console
high voltage generator

Front 2

Function of xray imaging system

Back 2

To provide a controlled flow of electrons intense enough to produce an xray beam appropriate for imaging

Front 3

Operating Console

Back 3

control the voltage applied to xray tube, the current through the tube and the exposure time

Front 4

Transformers

Back 4

Composed of 2 coils placed near on another (but NO electrical connection)

Front 5

Transformer

Back 5

Operating on alternating current and combining electromagnetic mutual induciton with application of Ohm's law.

Front 6

Transformer

Back 6

Used to increase or decrease voltage and current in a circuit

Front 7

Transformers

Back 7

Transforms electrical potential and current into higher or lower intensities

Front 8

Transformers

Back 8

Need alternating current to work because of changing direction constantly -establishes, collapses , re-establishes and recollapses its surrounding magnetic field.

Front 9

N

Back 9

Number of turns

Front 10

V

Back 10

Voltage (Potential difference or EMF)

Front 11

I

Back 11

current

Front 12

1

Back 12

Primary

Front 13

2

Back 13

Secondary

Front 14

Transformer

Back 14

A transformer is used to change the magnitude (strength) of voltage and current in an AC circuit

Front 15

Transformer Law

Back 15

The change in the applied voltage (V) on the primary side si directly proportional to the number of turns (windings) on the secondary side

Front 16

Transformer Law

Back 16

The change is he current (I) across the transformer is an INVERSE relationship, the opposite direction as volatge

Front 17

Transformer Law

Back 17

As voltage is stepped up (increased) current is stepped down (decreased)

Front 18

Turns Ratio

Back 18

Ns/Np

Front 19

Step-up Transformer

Back 19

A transformer with a turns ratio GREATER than 1

Front 20

Step-down Transformer

Back 20

A transformer with a turns ratio LESS than 1

Front 21

Closed Core

Back 21

Essentially 2 closed cores. More efficient than open core. Most currently used today. Square core of ferromagnetic material Uses laminated layers of iron

Front 22

Autotranformer

Back 22

Variable transformer. Single core on a central core. Acts as both primary and secondary coils. Based on self induction

Front 23

Autotransformer

Back 23

has one winding and varies voltage and current by self-induction

Front 24

Three important transformers in the xray imaging system.

Back 24

Autotransformer,
Step-Up Transformer
Step-Down Transformer

Front 25

Autotransformer

Back 25

Used to vary the incoming voltage to an appropriate level for the high voltage step-up transformer.

Front 26

High-Voltage Step-Up Transformer

Back 26

used to raise the incoming line voltage to the kV range necessary for x-Ray production

Front 27

Filament Step-Down Transformer

Back 27

is used to decrease the incoming line voltage to the 5-15 volt and 3-5 ampere range used to heat the xray tube filament

Front 28

Generators

Back 28

Single-Phase, Three-Phase,
High Frequency, Capacitor discharge mobile unit, Battery Operated mobile units, falling load

Front 29

Generator or dynamo

Back 29

device that converts mechanical energy to electrial energy

Front 30

Generator or dynamo

Back 30

uses: an armature, lip rings and brushes and a comunter ring (replaces slip rings)

Front 31

Single-Phase Generators

Back 31

Full wave rectified
2 pulses per Hz
120 pulses per second
Voltage Ripples 100 per cent

Front 32

Three Phase Generators
Full wave rectified w/ 6 diodes

Back 32

6 pulses/Hz
360 pulses per second
Voltage Ripple 13-25%

Front 33

Three Phase Generators
Full-Wave rectified w/ 12 didodes

Back 33

12 pulses/Hz
720 pulses per second
Voltage Ripple 4-10%