Unit 5: Secondary Circuit Flashcards

1
Q

Which transformer is located in the Secondary Circuit? what type is it?

A

high voltage step up transformer;
mutual induction;

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2
Q

what does the step up transformer do in the secondary circuit?

A

converts the low voltage that’s delivered by the autotransformer

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3
Q

x-ray exposures require voltage in the levels of:

A

kilovoltage

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4
Q

x-ray photon production uses extremely high levels of _______ and extremely small amounts of ________

A

voltage (kVp);
current (mA)

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5
Q

Power formula:

A

P = IV

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6
Q

When it comes to a fixed amount of voltage being sent to a transformer, what is the relationship between voltage and current?

A

as voltage goes up, current goes down and vise versa

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7
Q

on the step up transformer, what side are there more windings on?

A

the secondary

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8
Q

the primary side is measured in:
the secondary side is measure in:

A

volts (V);
kilovolts (kV)

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9
Q

the primary current is measured in:
the secondary current is measured in:

A

amperes (A);
milliamperes (mA)

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10
Q

why does the production of xray photons require AC?

A

mutual induction wouldn’t work without it

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11
Q

where is the mA meter located?

what does it ensure?

A

at a center tap on the output of the high voltage step up transformer;

electrical safety

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12
Q

current from a common wall plug is:

A

60 Hz AC

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13
Q

how many times does current change?

A

120x each second

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14
Q

AC is required for the process of:

A

mutual induction

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15
Q

x-ray tube requires a:

A

DC (electrons flowing in one direction)

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16
Q

what electronic device allows current flow in only one direction?

A

rectifier

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17
Q

a rectifier is a:

A

silicon semiconductor

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18
Q

reversal of electrons would be disastrous for the x-ray tube.

A

true

19
Q

if electron flow should only be from cathode to anode, the secondary voltage of the high voltage transformer must be _________.

A

rectified

20
Q

What is the purpose of the Rectifier Bridge?

A

to only allow electrons to flow in one direction

21
Q

What type of device is used to accomplish rectification?

A

diode

22
Q

how does a diode allow current flow in only one direction?

A

by not allowing one half of the current waveform to pass through

23
Q

what is rectified voltage?

A
24
Q

What is “half-wave” rectification and how is it accomplished?

A

where voltage isn’t allowed to swing negative during the negative half of its cycle.

by doubling the exposure time?

25
Q

What is “full-wave” rectification and how is it accomplished?

A

a circuit that rectifies the entire AC waveform;

by cutting exposure time in half and flipping the negatives up

26
Q

full wave rectification contains at least 4…

A

diodes

27
Q

half wave rectification wastes _____ of the power supply, while full wave rectification wastes _____ power

A

half; no

28
Q

The High Voltage Generator contains three parts…what are they?

A

high voltage transformer
filament transformer
rectifiers

29
Q

single phase power results in a __________ x-ray beam

A

pulsating

30
Q

x-rays produced when the single phase voltage waveform has a value near zero are of:

A

little diagnostic

31
Q

how do we maximize the energy emitted from the tube in single phase full wave rectification?

A

three phase power

32
Q

What is Three-Phase Power and why is it better than Single-Phase?

A

multiple voltage waveforms are superimposed on each other;

it results in a waveform that has nearly constant high voltage

33
Q

What type of generator will produce the highest average quality beam?

A

high frequency generator

34
Q

what is used in almost all stationary x-ray imaging systems?

A

full-wave and/or high frequency voltage generators

35
Q

What is “voltage ripple”?

A

voltage variation from zero to its max amount

36
Q

what is the voltage ripple for single phase half and full wave rectification?

A

100%

37
Q

what is the voltage ripple for three phase, six pulse:

A

14%

38
Q

what is the voltage ripple for three phase twelve pulse?

A

4%

39
Q

what is the voltage ripple for high frequency generator?

A

<1%

40
Q

What is a “Heat Unit”?

What is the unit of measure for a heat unit?

A

measurement for thermal energy

Joules (J)

41
Q

one heat unit =

A

1 kVp x 1 mAs x 1 second

42
Q

different generators produce different:

A

HUs

43
Q

How would you calculate the HU’s for a single-phase generator?

A

kVp x mA x seconds

44
Q

How would you calculate the HU’s for a three-phase or high frequency generator?

A

1.41 x kVp x mA x seconds