Packet Review on Generator Flashcards
all parts or circuit elements are connected in a continuous line ( a single electrical path)
series circuit
its current is able to flow beyond its continuous line ( or more than one pathway)
parallel circuit
any breaks causes the circuit to fail and stop working
series circuit
constant voltage decrease current
parallel circuit
a break still allows for the circuit to function
parallel circuit
constant current decrease voltage what kind of circuit
series circuit
add up all numbers
series circuit
find lowest number and cut it by a half
parallel circuit
What happens when more resistances are added to the parallel circuit
total resistance drops, amperage increases and total voltage remains unchanged
adding resistance in a parallel circuit
increases circuit temperature
the force given to each particle to move
- the force that pushes electrons through circuit
voltage
the flow of electrons in an electrical circuit
current
-amount of opposition to current
-measured in ohms
- based upon current type
-conductance (DC)
- Admittance (AC)
Resistance
electrons flow in a rapid back and forth changing direction
- transformers operate on this current
- direction is alternating
x-ray systems use this current
alternating current (AC)
an electrical components that inhibits the flow of current through a circuit
- measured in ohm’s
- designed to reduce current flow through a circuit
- decreases voltage
resistors
measure electrical current
- also referred to as intensity
amperage
allows for electrons to flow in one direction
- cathode to anode
- x-ray tube uses this current
direct current (DC)
x-ray tube uses what type of current
direct current
step up/ step down transformers use what type of current
alternating current (AC)
works by self- induction
- origin for voltage or kilovoltage
- has only one single coil
- KVP selection
- can be both step up or step down
- always present in coils supplied with alternating current
autotransformer
where is the autotransformer located
primary side
makes small changes to voltage
- works by self induction
- can be step up/ step down
autotransformer
converts alternating current to direct current
- converted by rectifiers ( most common is the solid state diode)
- comes in as AC
- goes out as DC
- allows electrons to flow in only 1 direction
rectification or rectifiers
where is the rectifier located
located between step up transformer and x-ray tube
solid states design acts like a one way gate
rectifier
What are considered mutual induction
step up transformer
step down transformer
change the voltage (polarity) in an electrical current
- they can increase or decrease voltage
transformers
the current will increase or decrease depending on number of turns/ windings on each side
- the side with more turns has higher voltage
tep up vs. step down transformer
increase voltage while also decreasing amperage
- changes volts to kilovolts
- more secondary turns
- high voltage section of x-ray system requires
step up transformer
where is the step up generator located
is in the primary side going to secondary side
decrease voltage increase amperage
- changes amps to miliamps
- mA selector
- creates heat needed for thermonic emission
- fewer coils
- more primary turns
step down transformer
where is your step down transformer located
in the filament
voltage and ampere have what kind of relationship for step up/ step down
inversely proportional
polarity of voltage rapidly changes back and forth
- dropping past zero
unrectified
the resistance of the particles to flow within a circuit
ohm’s
decrease of electrical potential along the path of current flowing in a circuit
voltage drop
electrons flowing in the revers direction are blocked
- staying above zero
rectified
which side has low voltage
primary side
which side has a high amperage or mA
filament
which side has the highest voltage
secondary side
where is the x-ray tube located
in the secondary side
where is the rectifier located
in the secondary side
a unit of measure of the degree of resistance between two points of a conductor within a circuit
ohm’s
number of distinct wave cycles
phase
where is the step up transformer located
in the secondary side
number of voltage pulses per cycle
pulse
number of pulses
frequency
fluctuation in voltage output of generator
- the net voltage produced during full wave rectification
voltage ripple
transformers have three parts:
iron core
primary coil (electricity in)
secondary coil (electricity out)
which rectification is described :
the gap between pulses has no electron flow ( no x-ray creation) and the other wave is blocked
half wave rectification
which rectification is described :
all electrons flow in the same direction
back flowing electrons are not blocked (their polarity is changed so they flow in the same direction)
no gaps between pulses, but wave drops to 0
full wave rectification
sets mA to be sent to filament
- controls filament heat/current for thermonic emission
- variable resistor
Rheostat mA selector
Where is the step down transformer located
filament
where is the cathode filament located
filament
where is the Rheostat and mA selector located?
filamet
- mutual induction
- more turns on primary side
- requires alternating current
decrease voltage increase amperage - more amps to filament mean more heat to make more electrons by thermonic emission
step down transformer
-changes AC to DC
- polarity changes
- wave rectificaation
electrons move in one direction
rectifier diode
- wall outlet
- 220v
main power supply
protects circuit from power surgery or short circuits
circuit breaker
-self induction
- single coil
- step up and step down
-makes small changes
- KVP selectors
- needs alternating current
auto transformer
voltage induced in secondary coil directly related to number of turns in primary coil
turns ratio
current induced in secondary coil is inversely related to voltage and number of turns in primary coil
turns ratio
voltage and ampere have what type of relationship in step up, step down
inversely proportional
number of secondary turns- to the number of primary turns
turns ratio
number of turns on secondary side divided by numbers turns on primary side
turns ratio
measured in volts (V)
- easy to read and convert to kilovolt (Kv)
KVP meter
can be controlled by time settings or AEC
exposure timer
- mutual induction
- more turns on secondary side
- makes large changes (V to KV)
- needs alternating current AC
- part of primary and secondary circuit
step up transformer
where is the main power supply located
primary side
where is the circuit breaker located
primary side
where is the auto transformer located
primary side
where is the KVP meter located
primary side
where is the exposure meter located
primary side
what is ohm’s formula
V=IR
v=voltage
I=current
R=resistance
xray tube energy is converted to:
mechanical to electrical
what waves are least efficient to most efficient
-half wave
-full wave
-3phase, 6 pulse
-3phase, 12 pulse
- high frequency
how much voltage ripple loss is in 3 phase 12 pulse
4 percent
how much loss is in 3 phase 6 pulse voltage ripple
13 percent
how much loss is in half and full wave voltage ripple
100 percent
how much voltage ripple in high frequency
1 percent
voltage induced in secondary coil directly related to number of turns in secondary coil
transformer law
what is the most common and most efficient transformer type
shell type
transformer types
Air Core
Open Core
Closed Core
Shell type
three divisions for basic xray circuit
Low voltage circuit
High tension circuit
Filament circuit
primitive form of current rectification
Performed by x-ray tube which acts as a diode device in the
circuit
X-ray tube not designed to be a diode rectifier
Produces a DC waveform that is 50% of full-wave rectification
Very inefficient x-ray production and damaging to tube
self rectification
Produces a DC waveform similar to self-rectification
Employs single rectifier in circuit
Protects x-ray tube from acting as a diode rectifier
o Protection is marginal
Inefficient x-ray production
Utilized in very inexpensive x-ray units
o Veterinary
o Podiatric
Half-Wave Rectification
Takes advantage of both phases of alternating current
* Provides only DC to x-ray tube
* Uses at least four rectifiers in a bridge rectification circuit
* Most efficient form of current for x-ray production
o All modern equipment is full-wave rectified
Full-Wave Rectification
what is the turns ratio
N(secondary) / N(primary)
An electrical component that inhibits the flow of current through a circuit
designed to reduce current flow through a circuit
decreases voltage
resistors
unrectified
- 1 pulse 1 phase
1 distinct wave form
form single phase
one distinct waveform
- half rectified
- 100% voltage ripple
- drops all the way to zero
single phase half way rectified
3 separate waves make the current
- full rectified 6 useful pulses
- 13% voltage ripple
3 phase 6 pulse full wave rectified
3 separate waves
- full rectified 12 useful pulses
- 4% voltage ripple
3 phase 12 pulse full wave rectified
thousands of pulses per wave cycle
- 1% voltage ripple
- barely drops in voltage more efficient for producing x-rays
high frequency
suppresses the negative portion
half wavee rectified
converts the negative cycle to positive portion
full wave rectification
use layers of iron to form ferromagnetic core
closed core
uses a central iron core
shell type
connected in series
- measures current flow
ammeter
connected in parallel
- measured potential difference between two points in circuit
voltmeter
coils turn at same rate as armature supplying current
synchronous motor
asynchronous
- variable speed
induction motor
commutator rings
DC motors
slip rings
AC motors
electrical storage
capacitor
have 95% efficiency
transformer
accumulates and stores electrical charge
- charged with DC voltage
capacitors
unit of capacitance
farad
The total amount of energy in a circuit
p= iv
The total resistance of a series circuit is measured in ohms,
add up all numbers
where is grounding located
in secondary side
Electrical process of liberating electrons from a wire filament
* Filament is heated to very high temperature, due to its resistance
o Filament is typically tungsten
* “Boiling off” electrons create an electron cloud around filament
* Principle of an incandescent light bulb
* Very important to x-ray tube design
thermionic emission
