Quiz Flashcards
Term used to refer to systems that combine computer controls,electrical components,and mechanical parts
Mechatronics
Obtains relevant information from surrounding environment to manage or regulate the behavior of a device performing desired operations
Automatic Control Systems
Automatic Control Systems generally consists of _________ to obtain information, a ___________ to make a decision and an ____________ to perform the actions that automate the operation
sensors, controller, actuator
It is an integrated part that receives an electrical signal to create a physical movement to drive a mechanical device performing a certain action
Actuator
Converts electric current to rotational motion
Electric motor
Converts electric current to linear motion that opens or closes a valve
Solenoid valve
Converts electric current to linear motion that extends or retracts piston
Electrohydraulic actuator
Class of devices that measure significant parameters by using a variety of physical phenomena
Sensors
Quantities in form of electrical variables (e.g. voltage, current) to represent measured physical quantities (e.g. temperature, pressure, light intensity), expressed in base-10 (decimal number system)
Analog data
expressed in base-2 (binary number system), 0 or 1; off or on
Digital data
Resolution of digital data depends on the number of __________, such that more __________ means more precision in the digitized measurement
bits
Measure of the electric field’s potential, analogous to potential energy in gravitational field, sometimes referred to as “electromotive force” or emf
Voltage
Defined as the time rate of flow of charge
Current
Voltage source adds energy to the electrons causing them to flow from the ________ side towards the __________ side
negative, positive
_________ side of the voltage source attracts the electrons, _________ side releases the electrons
Positive, negative
Standard convention assumes that the current flows from the __________ side of the voltage source, opposite the flow of the electrons
positive
Current describes the flow of ___________, not the electrons
positive charge
Voltage and current in the circuit are constant (i.e. independent of time)
Direct current
Voltage and current vary with time, usually sinusoidal
Alternating current
It is a material property whose value is the slope of the resistor’s voltage-current curve
Resistance
States that the electrical current flowing through a fixed linear resistance is directly proportional to the voltage applied across it, and also inversely proportional to the resistance
Ohm’s Law
provides energy to the circuit
Voltage
describes the flow of positive charge
Current
consists of network of circuit elements that may dissipate or store energy
Load
reference point in the circuit where voltage is assumed to be zero
Ground
Dissipative element that converts electrical energy to into heat
Resistor
For a 4-band resistor: the first two bands indicate _________, third band indicates _________,and the fourth band indicates ___________
digits, multiplier, tolerance
For an ideal resistor, the voltage-current relationship is ________, and the resistance is ________
linear, constant
A passive element that stores energy in the form of an electric field. This field is the result of a separation of electric charge.
Capacitor
A passive energy storage element that stores energy in the form of a magnetic field
Inductor
joules/coulomb
Volts
coulomb/time
Current
coulomb/volt
Capacitance (Farad)
weber/ampere
Inductance (Henry)
Code using symbols that refer to a number of items
Number system
Uses the ten symbols (base 10 system)
Decimal number system
Uses the two symbols (base 2 system)
Binary number system
Numeric value of symbols in different positions
Place value
number of digits in a binary number
Bits
Uses the 8 symbols (base 8 system)
Octal number system
Uses the 16 symbols (base 16 system)
Hexadecimal number system
An element in a mechatronic or measurement system that detects the magnitude of a physical parameter and changes it into a signal that can be processed by the system
Sensor
The active element of a sensor
Transducer
Often referred to as resistive transducers or variable resistance transducers. Most frequently used for calculating different physical quantities like pressure, vibration, temperature, force, and displacement, which is characterized by changing resistance due to the effect of the environment
Resistive sensors
Sensor resistance increases with increasing temperature
positive temperature coefficient
Sensor resistance increases with decreasing temperature
negative temperature coefficient
Sensor that has a resistive film sustained by a thin and flexible support. The entire structure is tightly attached to an object, and the deformation (tension and compression) of this object causes the deformation of the filament, in terms of length and cross section
Strain gauges
Sensor used to measure force. Contains an internally flexural element, usually strain
gauges. Usually connected to a bridge circuit to yield a voltage proportional to the load
Load cell
Most straight forward resistive sensor
Potentiometers
Also known as resistive photo detectors
Light-dependent resistors (LDR)
Sensor exhibits a modification of material resistivity ρ caused by interaction with specific gases
Resistive gas sensors
Sensors that can detect the nearness of a conductive material or a material with different dielectric property than the sensor’s electrodes
Capacitive sensors
Convert light rays into electronic signals
Optical sensors
Three common types of optical sensors
Through beam, Reflective, and Retro-reflective
Sensors that transform change in temperature to current. Typical example is the thermocouple
Thermoelectric sensors
It is the process of matching the output a sensor to a set of known reference values
Calibration of sensors
Done by plotting two variables (dependent and independent) and generating a best fit line using n order polynomial equation. Can be implemented on spreadsheets
Polynomial method
Difference between Maximum and Minimum value which can be sensed by the sensor
Range
The smallest change which can be sensed by the sensor
Resolution
Ratio of change in output to a unit change in the input
Sensitivity
Difference between the Measured Value and True Value
Error
It is inversely proportional to Error, i.e. How close the sensor reading is to the True Value
Accuracy
Ability to give/reproduce accurate value repeatedly
Precision
Time lag between the Input and Output
Response time
Ratio between the magnitude of the signal and the noise at the output
Signal-to-noise ratio
It should be compatible to use with a wide range of instruments
Interfacing
Type of sensor with a temperature and humidity range of 0C- 50C and 20%-90%, respectively
DHT11
Type of sensor with a temperature and humidity range of -40C- 80C and 0%-100%, respectively
DHT22
