Subsection 03 Data Conversion

Question 1

A charge balancing Analogue to Digital convertor ( ADC ) uses a closed loop system to compare?

Answer 1

The analogue input to give the required digital output.

Question 2

A Digital to Analogue convertor is required to produce an output range of 0 to -10v this can be achieved by?

Answer 2

An inverting OP AMP connected in series with output.

Question 3

A Digital to Analogue converter would use a Precision Amplifier to?

Answer 3

Ensure that the output voltages remain accurate

Question 4

A Digital to Analogue converter can produce 256 different output voltages, this DAC has a resolution of?

Answer 4

8 BITS

Question 5

A DAC converts?

Answer 5

Digital data to Analogue signals

Question 6

A DAC uses a precision amplifier to?

Answer 6

Ensure the output voltages remain accurate

Question 7

A Digital output of Binary 1100 from a 12v Maximum Analogue to digital converter would represent a Analogue input of?

Answer 7

9.6v

Question 8

A DAC has a resolution of 0.3v, what will be the analogue output when the digital input is 10110?

Answer 8

6.6v D.C.

Question 9

A DAC that requires the output to range between 0 and -10v would have?

Answer 9

An inverting amplifier in series with the output line.

Question 10

A digital voltmeter uses a?

Answer 10

ADC

Question 11

A dual slope ADC is more prone to timing errors due to the?

Answer 11

Increased level of complexity

Question 12

A Given transducer provides a voltage which corresponds to true heading, this voltage can be converted to “BITS” by using a?

Answer 12

ADC

Question 13

A Ladder resistive network with reference voltage and switching system, fed to a summing amplifier could be used as a?

Answer 13

DAC

Question 14

A Limitation of a flash ADC is?

Answer 14

It requires many parts

Question 15

A number represented as a physical quantity e.g. voltage or speed of rotation is?

Answer 15

ANALOGUE

Question 16

A precision op-amp is used in a DAC to?

Answer 16

Give an output at a required level

Question 17

An ADC uses successive approximation to?

Answer 17

Increase speed

Question 18

An ADC converts?

Answer 18

Analogue signals to digital data

Question 19

An ADC uses successive approximation to?

Answer 19

Increase speed

Question 20

An ADC requires?

Answer 20

A reference voltage, an input gate, an internal counter and a comparator.

Question 21

An ADC is as accurate as?

Answer 21

The sampling rate.

Question 22

An ADC where it counts up to binary state equal to the analogue input then back down again. When this is reached is a?

Answer 22

Ramp type converter.

Question 23

An encoder using Grey code changes?

Answer 23

Analogue to digital

Question 24

An input to a computer which will always require an ADC is?

Answer 24

A Microphone

Question 25

An output from a computer that requires a DAC is a?

Answer 25

Speaker

Question 26

An R-2R DAC has values of resistance whose precision are?

Answer 26

Not accurate

Question 27

An R-2R DAC uses two values of resistors whose precision is?

Answer 27

Not important

Question 28

Analogue Logic 1 is closed circuit, Logic Q = ?

Answer 28

1

Question 29

Audio data that is stored in MP3 format will require a DAC to ?

Answer 29

Broadcast it in the aircraft cabin

Question 30

Audio sounds recorded digitally are?

Answer 30

Superior quality and greater bandwidth

Question 31

Digital signals can be represented?

Answer 31

Only as a binary value

Question 32

If a signal has quantity in volts and physical position it is?

Answer 32

Analogue

Question 33

If an ADC has a resolution of 2%, 100v might be read as

Answer 33

99-101v

Question 34

In an Analogue to digital conversion, a signals bandwidth represents?

Answer 34

The maximum frequency range occupied by a signal

Question 35

In an ADC the input voltage?

Answer 35

Stays on constantly

Question 36

In a successive approximation ADC the time interval between the SC and EOC signal is?

Answer 36

The conversion time

Question 37

In a R-2R ladder converter the values of resistors?

Answer 37

Do not need to be of precise value.

Question 38

Op Amps generally used in ADC's and DAC's are normally?

Answer 38

Hi Input Impedance, Low Output Impedance

Question 39

Physical variables in quantative forms such as voltage or angular rotation of a shaft are?

Answer 39

Analogue

Question 40

Sample and hold is a technique used in?

Answer 40

Analogue to digital conversion

Question 41

The accuracy of a DAC is dependant upon?

Answer 41

The number of BITS and type of DAC

Question 42

The advantage of digital sound over analogue is?

Answer 42

Minimal errors and noise

Question 43

The counter ( or ramp ) ADC uses a counter in conjunction with a DAC to determine the?

Answer 43

Equivilant to the unknown digital input voltage

Question 44

The function of a commutator is to provide?

Answer 44

Sampling in sequence of a number of parameters

Question 45

The input of a DAC is?

Answer 45

Digital data

Question 46

The input of a ADC is?

Answer 46

Analogue data

Question 47

The limiting factor using a resistor based DAC is?

Answer 47

The quality and size of resistors

Question 48

The microphone in a mobile phone is an example of a?

Answer 48

ADC

Question 49

The sampling frequency of an ADC is precisely the frequency of the AC analogue signal being measured, the output of the ADC will be a series of digital values corresponding to?

Answer 49

A DC signal

Question 50

Transistors are used in a current triggered Digital to Analogue device to?

Answer 50

Change the state of the inputs

Question 51

What does 1 represent in an analogue system?

Answer 51

Switches closed, magnetised

Question 52

What is the " throughput rate " for the ADC?

Answer 52

The number of complete digital words encoded in a specified unit of time.

Question 53

What is the advantage of a digital ramp type ADC over a flash type?

Answer 53

Digital ramp type are much cheaper to manufactuer

Question 54

What is the advantage of a flash type ADC over a digital ramp type?

Answer 54

Flash operates at a much faster speed than digital ramp type.

Question 55

What is an advantage of an R-R2 ladder DAC over a binary weight resistor?

Answer 55

Only 2 resistor values are used and therefore greater accuracy is achieved particular with temperature variations

Question 56

What is serial to parallel and vica versa called?

Answer 56

Multiplex and Demultiplex

Question 57

What is the quickest method of ADC?

Answer 57

Flash converter

Question 58

What is the resolution of ADC and DAC converters?

Answer 58

Number of descrete values that can be represented by the digital word

Question 59

What may a digital ramp ADC also be known as?

Answer 59

Counter type ADC

Question 60

What type of ADC would be used if very high converting speeds are required?

Answer 60

Flash converter

Question 61

What type of DAC uses a different value of resistors for each input?

Answer 61

Binary weighted resistor DAC

Question 62

What type DAC uses two different value resistors in its construction?

Answer 62

R-2R ladder

Question 63

When converting analogue signals to digital the resolution is determined by?

Answer 63

The number of BIT's used to represent the signal

Question 64

What is the fastest ADC?

Answer 64

Flash type

Question 65

Within a computer controlled flight system, position feedback is converted from?

Answer 65

Analogue to digital