Ch 6. Circuit & Heat Mgmnt

Question 1

L.V.C
H.V.C
Filament circuit
Each contains a specific transformer

Answer 1

3 sections of the X-ray circuit

Question 2

between the AC power supply & the primary side of the high voltage (S.U.T)

Answer 2

Low voltage circuit

Question 3

-Technique selectors
-autotransformer
-exposure switch & timer
-main switch

Answer 3

components located in the control console

Question 4

single coil transformer with 3 functions:
- provides kVp selection
- provides compensation for fluctuations of incoming voltage
- supplies power to other circuits

Answer 4

autotransformer

Question 5

Primary purpose: vary voltage to the primary side of the S.U.T

Answer 5

Autotransformer purpose

Question 6

closes circuit to allow current flow to primary side of S.U.T

Answer 6

exposure switch

Question 7

Terminates exposure & is set on control console

Answer 7

Exposure Timer

Question 8

Begins & ends on the secondary side of the S.U.T; includes:
- tube & rectifier unit
- current only flows in this circuit during exposure

Answer 8

High Voltage Circuit

Question 9

PRIMARY PURPOSE: supply the tube with enough voltage to create xrays

Answer 9

high voltage circuit’s primary purpose

Question 10

divided into 2 parts by the S.D.T
- activated anytime mA is adjusted

Answer 10

Filament Circuit

Question 11

PRIMARY PURPOSE: supply low current to heat tube filament for thermionic emission

Answer 11

Filament Circuit’s Purpose

Question 12

changes AC to DC by using a diode

Answer 12

Rectification

Question 13

device that makes current flow in one direction

Answer 13

Diode

Question 14

Self-rectification: not used
Half-wave: 2 diodes; 60p/s; prevents “backflow” eliminating negative half of cycle
Full-Wave: 4 diodes; 120p/s; “redirect” current to have both pos. & Neg. flow in same direction

Answer 14

3 types of rectification

Question 15

Power comes from a single source of AC = a pulsating beam
- lowest power
- least expensive

Answer 15

single-phase generator

Question 16

power from 3 separate sources of AC
-increases output by 40%

Answer 16

Three-Phase generator

Question 17

Converts circuit to a higher frequency
- most used
- most consistent

Answer 17

High frequency Generator

Question 18

single-phase w Full-wave = 120p/s
Three-phase w Full-wave = 360 p/s
60 Hz Full-wave Circuit = 6000 Hz

Answer 18

pulses / second for each generator type

Question 19

terminates exposure time when a certain quantity of radiation has reached the IR
2 types:
-photo timer
-ionization chamber

Answer 19

Automatic Exposure Control

Question 20

• rotating anode
• oil between tube housing & tube provides insulation
• warm-up tube before large exposures
  -minimize repeats
• don’t use tube when you hear rotor bearings

Answer 20

how to prolong tube life

Question 21

Single-Phase Generators:
- HU= mAs x kVp
Three-Phase Generators:
- HU= mAs x kVp x 1.35
High Frequency Generators:
- HU= mAs x kVp x 1.40

Answer 21

Heat Unit Formulas