X-ray Circuitry

Question 1

Three sections of the x-ray circuit:

Answer 1

Primary circuit
Secondary circuit
Filament circuit

Question 2

the basic “on/off” switch connected to the power supply of the facility of the primary circuit

Answer 2

main power switch

Question 3

A device that acts in the same manner as a fuse. If the current flowing through it rises above a certain level, the circuit breaker flips its internal switch to open the circuit and stop the electric flow

Answer 3

Circuit breaker

Question 4

A device that raises or lowers voltage in the primary circuit.

Answer 4

Autotransformer

Question 5

A circuit made up of a mechanical or electronic device whose action is to start and stop the high voltage across the x-ray tube. It is nearly always located in the primary section

Answer 5

Timer circuit

Question 6

A device in the primary circuit that raises voltage to the kilovolt level needed to power the x-ray tube.

Answer 6

Step-up transformer

Question 7

The secondary circuit is made up of the secondary side of the:

Answer 7

Step-up transformer

Question 8

Secondary circuit components:

Answer 8

mA meter, rectifiers, x-ray tube (except filaments)

Question 9

A device placed in the tube circuit and used to monitor x-ray tube current

Answer 9

mA meter

Question 10

A device that converts alternating current to direct current by allowing the current to flow through it only in one direction

Answer 10

Rectifier

Question 11

Filament circuit components:

Answer 11

Rheostat, step-down transformer, filaments

Question 12

An appliance for regulating the resistance and thus controlling the amount of current entering an electric circuit

Answer 12

Rheostat

Question 13

A device included in the filament circuit to lower the voltage to the filament.

Answer 13

Step-down transformer

Question 14

To boost the 220V flowing to the x-ray machine to the thousands required to produce x-rays, a _____ is used.

Answer 14

transformer

Question 15

In a basic X-ray circuit, three transformers are used:

Answer 15

Autotransformer
Step-up transformer
Step-down transformer

Question 16

_____ is needed for transformers to operate correctly because, in effect, it creates a fluctuating magnetic field.

Answer 16

Alternating current

Question 17

Transformer Law

Answer 17

Vs/Vp = Ns/Np

V = Voltage
N = the number of turns
s = secondary coil
p = primary coil

Question 18

The number of coils in the primary and secondary coils determine whether there is an increase or decrease in the voltage of the secondary coil. This is expressed mathematically by the ______

Answer 18

Transformer Law

Question 19

if there are more turns in the secondary coil than the primary coil, Voltage in the secondary coil will ____

Answer 19

increase (step-up transformer)

Question 20

Consists of a single winding of wire that acts as the primary and secondary coil and self induces current

Answer 20

Autotransformer

Question 21

Considered the kVp selector

Answer 21

Autotransformer

Question 22

The autotransformer’s primary function is to provide a voltage that can then be increased by the step-up transformer in the primary circuit to produce the kilovolts needed for X-ray production. That increase is constant and roughly:

Answer 22

500x

Question 23

The dividing line between the Primary and Secondary circuit

Answer 23

Step-up transformer

Question 24

The step-up transformer [is/is not] adjustable

Answer 24

Is not

Question 25

"Filament transformer". Used to control the degree and duration that the filament is heated

Answer 25

Step-down

Question 26

Energy can neither be created or destroyed. The total energy of an isolated system remains constant

Answer 26

Law of Conservation of Energy

Question 27

If energy in a system is neither created or destroyed and resistance in the circuit remains a constant, then if there is a decrease in Voltage, there must be an ______ to balance the equation

Answer 27

Increase in Amps

Question 28

We can calculate the output current of a transformer using the following equation:

Answer 28

Ip/Is = Ns/Np

Question 29

Used to change AC to DC - only conducts electricity in one direction

Answer 29

rectifier

Question 30

Rectifier most used in today's x-ray circuits

Answer 30

Solid state diode

Question 31

Solid-state diode is made up of two semi-conducting crystals

Answer 31

P-type and N-type crystals

Question 32

has an abundance of "electron traps

Answer 32

P-type crystals

Question 33

has an abundance of freely moving electrons

Answer 33

N-type crystals

Question 34

electronics component made from a combination of a P-type and N-type semiconductor material with leads attached to two ends

Answer 34

Diode

Question 35

combination of a P-type and N-type semiconductor material

Answer 35

p-n junction

Question 36

The lead attached to the n-type semiconductor (negative) is called the:

Answer 36

cathode

Question 37

The lead attached to the p-type semiconductor (positive) is the:

Answer 37

anode

Question 38

When a voltage source is connected to a diode such that the positive side of the voltage source is on the anode and the negative side is on the cathode, the ____ becomes a conductor and allows current to flow

Answer 38

diode

Question 39

a passive element or part of the circuit that implements electrical resistance to reduce current flow among other uses.

Answer 39

Resistor

Question 40

a variable resistor that can vary the amount of resistance to a current in a particular part of the circuit thereby controlling the strength of the current.

Answer 40

Rheostat

Question 41

In the _____ of the X-ray tube, we are controlling the current that is supplied to the filaments by using a rheostat to change the resistance to the current

Answer 41

filament circuit

Question 42

Technologists have direct control of the rheostat through the ______ settings on the control panel.

Answer 42

mA or mAs

Question 43

A setting of 100 mA will have _____ the resistance as a setting of 1000 mA

Answer 43

10x

Question 44

When various mA settings are selected, the rheostat is used to increase or decrease the amount of ____ to the filament

Answer 44

current flow

Question 45

The rheostat in the filament circuit controls the current going to the filament thereby controlling the _____ of the filament.

Answer 45

temperature

Question 46

The purpose of the filament circuit is to “boil” off electrons from the filament wire in a process referred to as ______

Answer 46

thermionic emission

Question 47

rheostat controls the _____ in the filament circuit and filament

Answer 47

resistance

Question 48

A device that regulates the length of time the electrons are allowed to cross the tube and, therefore, the time x-rays are produced to create a radiographic image

Answer 48

Exposure timer

Question 49

For any given exposure, the number of X-rays that reach the IR is directly related to:

Answer 49

X-ray tube current and the time that the tube is energized

Question 50

When the timer reaches its limit and opens a switch, flow through the _____ stops thereby stopping power to the tube

Answer 50

primary circuit

Question 51

Four basic types of exposure timers:

Answer 51

Synchronous, electric, mAs, AEC

Question 52

this timer is based on a synchronous motor which is a specialized motor designed to turn a shaft at exactly 60 cycles or revolutions per second.

Answer 52

Synchronous timer

Question 53

Timing circuit based on the time required to charge a capacitor through a variable resistor

Answer 53

Electric timer

Question 54

special kind of electronic timer that monitors the product of mA and exposure time and terminates the exposure when the desired mAs value is attained.

Answer 54

mAs timer

Question 55

Because the mAs timer must monitor actual tube current, it is usually located on the ____ of the high voltage (step-up) transformer

Answer 55

Secondary side

Question 56

A timing device that measures the amount of radiation that reaches the IR

Answer 56

AEC

Question 57

Another term for AEC

Answer 57

Phototimer

Question 58

Most AEC’s use a ____ that is situated between the patient and the IR thereby making the patient that determines exposure length

Answer 58

flat panel ionization plate (or chamber)