MOD 6 XRAY CIRCUITS

Circuit

Controls the flow of electrons in x-ray systems.

Primary Circuit

Includes main power switch and step-up transformer.

Autotransformer

Converts 220 volts to selected kVp for x-ray.

Secondary Circuit

Contains x-ray tube and rectifier bank components.

Filament Circuit

Supplies voltage to generate projectile electrons.

Line Compensator

Adjusts voltage to maintain 220 volts precisely.

Circuit Breakers

Protect against short circuits and electric shock.

Step-Up Transformer

Increases voltage for x-ray production from autotransformer.

Timer Circuit

Controls the timing of voltage across x-ray tube.

Exposure Timers

Regulate x-ray emission duration based on settings.

Mechanical Timers

Inexpensive timers for exposures over 250 ms.

Synchronous Timers

Minimum exposure time of 1/60 second.

Electronic Timers

Most accurate timers for rapid serial exposures.

mAs Timers

Controls tube current and terminates exposure at mAs.

Automatic Exposure Control

Terminates exposure when sufficient radiation is detected.

Spinning Top Test

Checks accuracy of exposure timer functionality.

mA Meter

Monitors x-ray tube current in the secondary circuit.

Rectifiers

Convert AC to DC using silicon components.

Solid-state Rectifier

Commonly used rectifier in x-ray circuits.

High-Voltage Generator

Converts low voltage to kilovoltage for x-ray.

Rheostat

Adjusts resistance in the filament circuit.

Step-Down Transformer

Decreases voltage for the filament circuit.

Filaments

Where projectile electrons are generated for x-ray.

Solid-state Rectifier

Converts low voltage to kilovoltage waveform.

High-Voltage Transformer

Step-up transformer increasing voltage from primary to secondary.

Turns Ratio

Ratio of secondary to primary windings in transformers.

Rectification

Converts alternating voltage to direct voltage.

Valve Tubes

Act as rectifiers in electrical circuits.

Self-rectification

X-ray tube property allowing current in one direction.

Half-wave Rectification

Allows voltage swing only in positive cycle.

Full-wave Rectification

Reverses negative cycle for continuous positive voltage.

Single-phase Power

Produces pulsating x-ray beam with low energy.

Three-phase Power

Generates three voltage waveforms for constant exposure.

High-Frequency Generator

Provides nearly constant potential, improving image quality.

Inverter Circuits

Convert DC into square pulses for generators.

Capacitor Discharge Generator

Uses NiCd battery to store and discharge electricity.

Falling-load Generator Control Circuit

Delivers maximum mA for selected kVp efficiently.

Capacitor Discharge on Mobile Units

Charges capacitor before exposure for x-ray tube discharge.

Voltage Ripple

Variation in peak voltage waveform during operation.

Single-Phase Generator

100% voltage ripple, varies from zero to maximum.

Three-Phase Generator

13% ripple for 6-pulse, 4% for 12-pulse.

High-Frequency Generator

Less than 3% voltage ripple for stable output.

Maximum Available Power

Standard for specifying high-voltage generators.

Rheostat

Variable resistor controlling mA on operating console.

Filament Circuit

Produces thermionic emission by boiling electrons.

Filament Heating Purpose

Controls electron emission for tube current.

Step-Down Transformer

Reduces voltage to increase filament current.

Large Focal Spot

Used for imaging large anatomical structures.

Small Focal Spot

Used for imaging small anatomical structures.

kVp

Determines voltage through autotransformer adjustments.

Step-Up Transformer

Increases voltage via mutual induction.

Rectification

Converts AC to DC for x-ray tube.

Rheostat

Sets resistance in filament circuit.

X-ray Quantity

Number of x-rays, measured in mR.

X-ray Quality

Penetrating power, expressed in kVp or HVL.

Extending Tube Life

Use minimum mA, kVp, and exposure time.

Warm-Up Procedures

Prepares tube for high heat load.

Initial Warm-Up Exposure

50 kVp, 100 mA for 1/30 second.

Filament Tungsten Deposition

Causes electron strikes on glass envelope.

Gassy Tube

Gas formation from electron strikes, causing failure.

Punctured Tube Diagnosis

Oil enters tube, audible during rotation.

Carelessness Effects

Handling issues may break glass envelope.

Anode Damage

Surface crazing reduces radiation output.

Rotor Bearing Damage

Slows rotation, may release gas.

Filament Aging

Thinning reduces mA due to vaporization.

Tube Housing Damage

Oil escape reduces insulation, harmful operation.

Stator Damage

Broken windings cause rotation issues.