4th Year Review Flashcards
AND gate truth statement
Any low gives a low
A•B=Y
OR gate truth statement
Any high gives a high
A+B=Y
NAND gate truth statement
Any low gives a high
—-
A•B=Y
NOR gate truth statement
Any high gives a low
——
A+B=Y
NOT (inverter) gate truth statement
Output is opposite input
-
A=A
XOR gate truth statement
A or B, not both
- -
A•B + A•B=Y
What is the main outstanding feature of using ‘gray code’ for use with transducers?
Changes by one bit per position
What is ASCII used for?
Coding computer inputs into binary
De-coding it back so we can understand
When a flip-flop is preset it stores a binary __ (1 or 0)
1
To set or clear a flip-flop, must the signlas applied to the PR and CLR inputs be permanent?
No
Can a single flip-flop store more than one binary bit of data to Q?
No
Which is considered the primary output of a flip-flop;
-
Q or Q?
Q
When 1 is present at the Q output of a flip-flop, it is said to be in the _____ (set/reset) condition.
Set
Another term used for a flip-flop being in the clear condition is that it is ______ (set/reset).
Reset
By applying a low to the PR input the J-K flip-flop will be _____ (set/reset).
Set
By applying a low to the CLR input the J-K flip flop will be _____ (set/reset)
Reset
When J and K inputs are both 1, and an appropriate clock pulse occurs, what happens to the flip-flop’s Q input?
It changes
What gate is this?
AND gate
What gate is this?
OR gate
What gate is this?
NAND gate
What gate is this?
NOR gate
What gate is this?
NOT (inverter) gate
What gate is this?
XOR gate
What is the expected input impedance of the ideal op-amp?
High
You want the input voltage to be amplified. If there were a low impedance path through the inputs there would be a volt drop and an incorrect input
What is the expected output impedance of the ideal op-amp?
Low
Once the voltage has been amplified you want that voltage to be seen across the load
List two practical applications where you would find op-amps being used in real world equipment.
PLC’s
VFD’s
What does OP-AMP stand for?
Operational amplifier
Is the following op-amp inverted or non inverted?
What would be the equation to find gain?
Non inverted
50Kohm/1Kohm +1
Is the following op-amp inverted or non inverted?
What would be the equation to find gain?
Inverted
27Kohm/3.3Kohm
An operational amplifier has two inputs. What are they called?
Inverting
Non inverting
What is the difference between open-loop and closed-loop operation of an op-amp?
Open loop - no feedback, high gain, unstable
Closed loop - feedback, low gain, stable
Not a question, just study this bitch
YAGA
List a reason for using negative feedback when operating an op-amp.
Controls the gain without distortion
What type of power supply is used for an op-amp?
DC dual voltage with a center reference
Give two examples of process variables
Speed
Position
Fluid pressure
Liquid level
Liquid flow
Temperature
What is open loop?
Not automatic
No feedback
Requires operator
What is closed loop?
Automatic
Feedback
No operator required
What is a transducer?
Converts energy from one form to another
List four types of linear motion sensors
Potentiometer
Variable inductor
Variable capacitor
Variable differential transformer
What are three common uses of sensors? (What do they detect?)
Motion
Force
Temperature
Light
Position
Fluid pressure/flow
What is a bonded wire strain gauge used to sense?
Force
List three type of fluid pressure sensors
Bourdon tube
Bellows
Diaphram
Which device consists of two dissimilar metals that when heated produce a small voltage?
Thermocouple
Which feedback sensor would produce a small voltage when subjected to vibration?
Piezo electric crystal
Which two signals does a comparator use to determine an error signal?
Set point
Feedback
What is the function of an actuator?
Converts electrical energy to;
Motion
Heat
Light
What does a solenoid do?
Provides linear motion
What is a sensor?
Measures and senses the process variable and provides feedback to the controller
What type of sensor is this?
Linear motion potentiometer. Works with both AC and DC
What type of sensor is this?
Linear motion variable inductor. Works with AC only
What is an actuator?
A device that converts an input signal into mechanical motion
What is the process variable?
A variable that needs to be controlled
What is the set point?
The desired value of the process variable
Who has the authority or jurisdiction of emergency and exit installations?
CEC - general wiring of installation
NBC - governs where equipment is required
Briefly describe standby power supply
A reliable source of power that is available either automatically or manually to maintain current supply to essential loads
List four different places that commonly use a standby power supply
Hospitals
Schools
Airports
Shopping centers
What are UPS systems usually used for?
Provide backup power to critical loads
Provides power conditioning to sensitive loads
What are the two main classifications of UPS systems?
Online and offline
What is the difference between the two classifications of UPS systems?
Online: zero transfer time as the charger, batteries and inverter are always supplying the load
Offline: short transfer time as the static transfer switch goes from normal power to battery and inverter supplying the load
