Deck 6: Special Purpose Motor, Control Devices and Programmable Logic Controllers

Question 1

The permanent magnetic DC motor acquires its magnetic field from a permanent magnetic and an electromagnetic.

Answer 1

False

Question 2

The figure of merit is a number that provides an objective method of determining the relative ability of a permanent magnetic motor.

Answer 2

True

Question 3

A conventional PM motor is also known as a wound rotor PM motor.

Answer 3

True

Question 4

The permanent magnetics of the conventional PM motor are magnetized along their length or their width.

Question 5

Both the speed -torque and the current -torque curves are linear for the permanent magnetic motor.

Question 6

The coreless motor is chosen over the wound -rotor motor in high -torque applications.

Question 7

The disk structure of a coreless motor is like a double -sided printed wiring board.

Question 8

The Hall effect sensor produces a current in the presence of a magnetic field.

Question 9

The stepper motor is capable of incrementally controlling the velocity, distance, and direction of its mechanical load.

Question 10

Detent torque is the maximum load -originating torque that the motor can stand without moving from its position with the stator energized.

Question 11

In a stepper motor, only one stator winding is energized at a time as the north pole.

Question 12

One advantage of the variable reluctance stepper motor is that it has much more holding torque than permanent magnetic stepper motor.

Question 13

A three -phase variable reluctance stepper motor with twelve stator windings has the windings set thirty degrees apart.

Question 14

The unidirectional mode of a stepper motor is used for slewing.

Question 15

The micro -stepping mode generates small stepping angles through motor current control via PWM of the excitation voltage of the rotor windings.

Question 16

The inability of stepper motors to follow the step command exactly results in damping followed by oscillations.

Question 17

In an AC servomotor, the voltage applied to the fixed winding and the voltage applied to the control winding are either in phase or ninety degrees out of phase.

Question 18

The servo motor controller has replaced the servo amplifier for most applications.

Question 19

An optical encoder is a sensor.

Question 20

Light is alternately passed and blocked to the light sensor as the optical encoder disk rotates.

Question 21

The determination of the direction of rotation by an optical encoder is independent of the number of tracks.

Question 22

When the on -off transitions from each of the two tracks of an optical encoder are counted, the resolution is increased by a factor of eight.

Question 23

The total encoder error is the sum of the instrument error, quadrature error, interpolation error, and quantization error.

Question 24

The stator windings directly exit the resolver.

Question 25

The single -phase operation of a resolver uses the variation in phase shift to determine shaft position.

Question 26

The two -phase operation of a resolver uses the variation in voltage amplitude to determine shaft position.

Question 27

In single -phase operation of a resolver, one of the stator windings is shorted.

Question 28

Which of the following is not an advantage of a permanent magnetic motor over a field wound motor?

A) It needs only one power supply.
B) It has lower inertia.
C) Its flux is always constant.
D) It has higher efficiency.

Question 29

Which of the following is not an excitation mode of a stepper motor?

A) three -phase modified
B) single -phase modified
C) micro -stepping
D) two -phase modified
E) half -stepping

Question 30

Which of the design requirements are not needed in all servo motors?

A) Capability to operate at standstill
B) Capability of operate over a range of speeds without overheating
C) Capability to operate with one voltage driving the field and armature windings
D) Sufficient torque to hold a load in a fixed position
E) Smooth acceleration in the forward and reverse directions

Question 31

Match the benefit to its motor .

-Responds quickly to changes in speed

A) Torque motor
B) Coreless motor
C) Brushless DC motor

Question 32

Match the benefit to its motor .

-Responds quickly to change in input voltage

A) Torque motor
B) Coreless motor
C) Brushless DC motor

Question 33

Match the benefit to its motor .

-Has no eddy currents and hysteresis losses

A) Torque motor
B) Coreless motor
C) Brushless DC motor

Question 34

Match the benefit to its motor .

-Eliminates the cogging effect

A) Torque motor
B) Coreless motor
C) Brushless DC motor

Question 35

Match the benefit to its motor .

-Operates at a stalled condition for long periods of time

A) Torque motor
B) Coreless motor
C) Brushless DC motor

Question 36

Match the benefit to its motor .

-Has an electronic commutator

A) Torque motor
B) Coreless motor
C) Brushless DC motor

Question 37

Match the benefit to its motor .

-Can operate continually at low speed

A) Torque motor
B) Coreless motor
C) Brushless DC motor

Question 38

Match the advantage to its encoder.

-Does not depend on a count to determine position

A) Absolute encoder
B) Absolute and incremental encoders
C) Incremental encode

Question 39

Match the advantage to its encoder.

-Provide high -speed line drivers as a serial output

A) Absolute encoder
B) Absolute and incremental encoders
C) Incremental encode

Question 40

Match the advantage to its encoder.

-Uses a reference starting point

A) Absolute encoder
B) Absolute and incremental encoders
C) Incremental encode

Question 41

Match the advantage to its encoder.

-Generally a lower cost device

A) Absolute encoder
B) Absolute and incremental encoders
C) Incremental encode

Question 42

Match the advantage to its encoder.

-Does not lose information because of a power dropout

A) Absolute encoder
B) Absolute and incremental encoders
C) Incremental encode

Question 43

Match the features to its motor .

-Poor reliability

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 44

Match the features to its motor .

-Good reliability

A) Brushless motor
B) Permanent magnetic motor
C)Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F)Brushless motor and stepper moto

Question 45

Match the features to its motor .

-Runs hot

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 46

Match the features to its motor .

-Runs cool

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F) Brushless motor and stepper moto

Question 47

Match the features to its motor .

-Moderately precise

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 48

Match the features to its motor .

-High to medium speed range

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 49

Match the features to its motor .

-Very precise

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 50

Match the features to its motor .

-High to low speed range

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 51

Match the features to its motor .

-High torque power

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 52

Match the features to its motor .

-Medium torque power

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 53

Match the features to its motor .

-Low torque power

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 54

Match the features to its motor .

-High efficiency

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 55

Match the features to its motor .

-Low efficiency

A) Brushless motor
B) Permanent magnetic motor
C) Permanent magnetic motor and brushless motor
D) Permanent magnetic motor and stepper motor
E) Stepper motor
F ) Brushless motor and stepper moto

Question 56

PLCs conform to an international standard called IEC 61131.

Question 57

The PLC standard does not include the ladder logic programming language because most US manufactures of PLCs have there own proprietary ladder logic language.

Question 58

The current PLC standard has 9 parts.

Question 59

The machine architecture for a PLC is the same as that used for a personal computer with the exception of a hard drive.

Question 60

The DeviceNet module is used to communicate primarily with motor controllers.

Question 61

To communicate with sensors, the PLC uses a SERCOS interface.

Question 62

The personal computer is the most commonly used programming device for PLCs.

Question 63

PLC modules get their power and data communication over the backplane.

Question 64

ControlNet uses the product/consummer model, is highly deterministic and repeatable, and is ideal for interfacing with smart sensors.

Question 65

DeviceNet, ControlNet, and Internet/IP are all international standards used by PLC vendors.

Question 66

DeviceNet and ControlNet use scanner modules to interface to the PLC.

Question 67

A valve stack would be a likely device connected to ControlNet but another PLC is usually never connected to ControlNet.

Question 68

In Ethernet/IP the IP stands for international protocol.

Question 69

PLCs introduced in the future will have variable -based addressing for variables and not rack/slot addressing.

Question 70

In rack/slot addressing the slot location of the PLC processor is indicated in the address.

Question 71

Soft PLC in the Allen Bradley system is PLC software that runs on a personal computer.

Question 72

Dick Bradley is the inventory of the PLC.

Question 73

Relay ladder logic and ladder logic for a PLC program are similar because the output symbols and control logic are on a rung, but different because the PLC ladder never has field device switch contacts located in it.

Question 74

The IEC 61131 ladder logic symbol library has only input contacts and output symbols available.

Question 75

Scan time is the time it takes for the PLC to read all input data and write that data into an input register.

Question 76

Examine on contacts look like NO contact symbols and must have NO contacts on the associated field device wired to the input pin for that address.

Question 77

The TOF timer for SLC 500 PLC turns the done bit off when the accumulator reaches the preset value.

Question 78

The RTO timer in an SLC 500 PLC must use a reset command to force the accumulator back to a zero value.

Question 79

Comparitors in the SLC 500 PLC must always be used on the input or right side of the ladder rung.

Question 80

The done bit of a CTD counter in an SLC 500 PLC turs on when the accumulator counts up to the preset value.