Term
| What is the purpose of the operating console? |
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Definition
| To allow the tech to control the x-ray tube current (mA) and voltage (kVp) |
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Term
| What are the 3 principle components of every x-ray imaging system? |
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Definition
1. x-ray tube
2. operating console
3. high voltage generator |
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Term
| ________ refers to the # of x-rays (intensity) expressed in milliroentgens (mR) or milliroentgens/milliampere - seconds (mR/mAs) |
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Definition
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Term
| _______ refers to penetrability expressed as kilovoltage (kVp) or half value layer (HVL) |
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Definition
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Term
| Pick One: all the circuits connecting the meters and controls are at (low/high) voltages to minimize electrical shock hazard. |
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Definition
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Term
Most x-ray machines operate at _____ V of power, however, some are at _____ V and
_____ V. |
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Definition
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Term
| ______ ______: incorporates a meter to measure the voltage and a control to adjust the voltage to precisely 220 V. |
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Definition
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Term
| ________ is defined as an electrical device operating on the principle of mutual induction to change the magnitude of current and voltage. |
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Definition
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Term
| A ______ (aka dynamo) converts mechanical energy to electrical energy by electromagnetic induction. |
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Definition
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Term
| _______ _______: an electric current is induced in a circuit if some part of that circuit is in a changing magnetic field. |
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Definition
| Electromagnetic Induction |
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Term
| Faraday's Law: the magnitude of the induced current depends on four factors, they are: |
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Definition
1. The strength of the magnetic field
2. Velocity of the magnetic field as it moves past the conductor
3. Angle of the conductor to the magnetic field
4. Number of turns in the conductor |
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Term
| _______: is a device that converts electrical energy to mechanical energy. |
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Definition
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Term
| A ______ uses mechanical energy like a hand crank, water, etc., to produce an electrical current. A ______ uses the electrical current to provide a mechanical motion. |
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Definition
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Term
| What type of current must a transformer have to operate? |
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Definition
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Term
| True or False: a transformer establishes and provides the collapsing fields that induce the voltage changes in the secondary coil. |
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Definition
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Term
| True or False: transformers convert one form of energy to another. |
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Definition
| False: it doesn't, it transforms electric potential and current into higher and lower intensity. |
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Term
| The transformer is used to change the magnitude of voltage and current in an AC circuit. This change is ______ proportional to the ratio of the number of turns of the secondary coil to the number of turns of the primary coil. |
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Definition
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Term
| Name the five types of transformers: |
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Definition
1. Air-core
2. Open Core
3. Closed Core
4. Shell-type
5. Autotransformer |
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Term
| A transformer with a turns ratio greater than one is a step-____ transformer. |
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Definition
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Term
| A transformer with a turns ratio less than one is a step-____ transformer. |
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Definition
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Term
| What are the 3 main causes of transformer inefficiency? |
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Definition
1. Resistance: caused by copper wire
2. Hyperesis: additional resistance causing the alternating reversal of the magnetic field
3. Eddy Current |
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Term
| ________ is the process of changing AC current into DC current. |
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Definition
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Term
| The tube requires current flow in how many directions? |
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Definition
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Term
| The _______ is the electronic device that keeps the current in the tube flowing in one direction only. |
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Definition
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Term
| Rectification is accomplished by the _____. |
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Definition
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Term
| _____: is an electronic device containing two electrodes. |
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Definition
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Term
| What are the two types of diodes? |
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Definition
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Term
| What type of diode has loosely bound electrons that flow between conduction bands? |
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Definition
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Term
| What type of diode has electron traps of + charged holes that attract and hold electrons? |
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Definition
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Term
| ______ ______ ______: the negative half of the current is supressed (below the line) emits x-rays only half the time. |
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Definition
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Term
| ______ ______ ______: the negative half of the current is changed to positive and now lies above the line. Cuts exposure time in half. |
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Definition
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Term
| What are the types of generators? (name 6) |
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Definition
1. single phase
2. three phase (both 6 and 12 pulse)
3. capacitor discharge
4. battery operated
5. high frequency
6. falling-load |
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Term
What type of generator?
- self-rectification, 1-2 diodes
- suppresses inverse voltage
- 120 pulses per second
- improves heat loading of the x-ray tube
- only uses half the power
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Definition
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Term
What type of generator?
- 3 pulse (waves)
- potential difference never drops to zero
- produces voltage ripple
- 360 pulses/second (6 and 12 pulse also)
- has three single phase currents out of step 120 degrees
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Definition
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Term
| Name 3 advantages of a 3 phase generator: |
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Definition
1. high mA w/ short exposure
2. nearly constant potential
3. high effective kV |
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Term
What type of generator?
- uses a capacitor (stores the charge)
- works on DC current (stored charge)
- Disadvantages: may continue to discharge after the usable exposure
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Definition
| capacitor discharge - used by mobile units |
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Term
What type of generator?
- battery supplies DC to a rotary converter which changes to 3-phase 6 pulse AC
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Definition
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Term
What type of generator?
- starts at a high mAs and then automatically adjusts down
- have to be used with AEC or mAs control
- disadvantage: wears out the filaments quicker
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Definition
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Term
What type of generator:
- starts with 3-phase power
- charges a capacitor bank to DC
- high frequency converter changes back to AC
- the swissray room uses this type of generator
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Definition
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Term
| Single phase power has a ___% voltage ripple in either half or full wave rectification. |
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Definition
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Term
| A three phase, six pulse has a voltage ripple of __%, meaning the voltage only "ripples" off maximum by __% |
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Definition
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Term
| A three phase, twelve pulse generator has a voltage ripple of __% |
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Definition
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Term
| A high frequency generator has a voltage ripple of less than __%. |
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Definition
| 1 - making it nearly constant |
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Term
| Transformers and Generators usually are identified by their power rating in _______. |
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Definition
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Term
Current x Potential = Power or _______ x _______ = _______ |
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Definition
| Amperage, Voltage, Watts (or kW in most cases) |
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Term
| For single phase generators you need a conversion factor of ___ due to its inefficiency. |
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Definition
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Term
| The operating console consists of what 5 things? |
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Definition
1. On/Off controls
2. kVp controls
3. mA controls
4. Time selector
5. AEC |
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Term
| There are two ciruits in the x-ray machine, the _______ circuit and the _______ circuit aka as the _______ circuit. |
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Definition
| Main, Secondary (Filament) |
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Term
| The Main Circuit has a primary side (____ voltage) and a secondary side (____ voltage). |
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Definition
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Term
| There are four major components of the timer circuit, they are: |
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Definition
1. exposure switch
2. mAs timer
3. electronic timers
4. AEC |
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Term
| What is the turns ratio formula for voltage (also known as the "Autotransformer Law")? |
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Definition
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Term
| What is the turns ratio formula for current? |
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Definition
| Ip/Is = Ns/Np (current is inversely proportional) |
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