MODULE 1: Intro and Fundamentals of vacuum tubes Flashcards by Keana Bautista

It is the technology based on the behavior and properties and controls of electrons

electronics

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is the premier nanoprocessing and nanotechnology journal focusing on fabrication of electrnic, photonic, bielectronic, electro mechanic and fluidic devices

mircoelectronics

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a branch of electronics in which electronic instruments and equipment are used for such medical application

biomedical electronics

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the process of analyzing and modifying
a signal to optimize or improve its efficiency or performance. It involves
applying various mathematical and computational algorithms to analog and
digital signals to produce a signal that’s of higher quality than the
original signal.

DIGITAL SIGNAL PROCESSING

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is the field of electrical engineering, and now to some
extent computer engineering and information technology, which deals
with radio and television broadcasting.

BROADCAST ENGINEERING

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involves both
the studio end and the transmitter end (the entire airchain), as well as remote
broadcasts.

BROADCAST ENGINEERING

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is the branch
of engineering dealing with sound and vibration. It is the application
of acoustics, the science of sound and vibration, in technology.

ACOUSTICAL ENGINEERING OR ACOUSTIC ENGG

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____________ engineers are typically concerned with the design, analysis and control of
sound.

ACOUSTIC ENGINEER

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helps to produce a recording or a performance, editing and
adjusting sound tracks using equalization and audio effects, mixing,
reproduction, and reinforcement of sound.

AUDIO OR VOCAL OR RECORDING ENGG

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is a technology professional who has the necessary skills to
plan, implement and oversee the computer networks that support in-house
voice, data, video and wireless network services.

NETWORK ENGINEER

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is a discipline founded around the
exchange of information across channels via wired or wireless means. It brings
together all of the elements of electrical engineering, including
computer engineering and system engineering, to create and
improve telecommunication systems.

TELECOMMUNICATIONS ENGINEERING

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A field of electronics that prepares individuals to apply technical knowledge
and skills to assemble, install, operate, maintain, and repair
electrical/electronic equipment used in industry and manufacturing.

INDUSTRIAL ELECTRONICS

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is a multidisciplinary field of science that includes a
combination of mechanical engineering, electronics, computer engineering,
telecommunications engineering, systems engineering and control
engineering.

MECHATRONICS

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A
typical ___________ system picks up signals from the environment, processes
them to generate output signals, transforming them for example into forces,
motions and actions.

MECHATRONIC

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is a branch of engineering that involves the conception, design,
manufacture, and operation of robots.

ROBOTCS

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Give Asimov’s three laws of robotics

Robots must never harm human beings.
Robots must follow instructions from humans without violating rule 1.
Robots must protect themselves without violating the other rules.

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It is a basic electronic element that is available
in a discrete form that has two or more
electrical terminals.

ELECTRONIC COMPONENT

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What are the two classification of electronic components

Passive and active devices

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These are components incapable of controlling current

by means of another electrical signal.

PASSIVE DEVICES

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Give examples of passive devices (prcitd)

Resistors, capacitors, inductors, transformers, and even

diodes

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any type of circuit component with
the ability to electrically control electron flow
(electricity controlling electricity).

ACTIVE DEVICES

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GIVE EXAMPLES OF ACTIVE DEVICES

vacuum
tubes, transistors, silicon-controlled rectifiers (SCRs),
and TRIACs.

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Devices utilizing a static voltage as the controlling

signal are called _________

voltage-controlled devices.

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Devices working on the principle of one current

controlling another current are known AS _____

current controlled

devices.

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Derived from the Greek word “atomos”, | meaning “indivisible”

ATOM

It is the tiny basic building block of all matters. Electronics

ATOM

Proposed by Sir Joseph John Thomson in 1904

THOMSON MODEL OR PLUM PUDDING

J. J. Thomson considered that the structure of an atom is something like a _____, so that his atomic model is sometimes called the _______

RAISIN, RAISIN BREAD MODEL

He assumed that the basic body of an atom is a spherical object containing electrons confined in homogeneous jellylike but relatively massive positive charge distribution.

JJ THOMSON

Proposed by Ernest Rutherford in 1911 (GIVE 2 TERMS)

RUTHERFORD MODEL OR PLANETARY MODEL

electric charge in an atom is not distributed over the whole area of the atom but concentrates in a small area, he called the nucleus. (WHAT MODEL)

PLANETARY MODEL

He published his atomic theory describing the atom as having a central positive nucleus surrounded by negative orbiting electrons.

RUTHERFORD

This model suggested that most of the mass of the atom was contained in the small nucleus, and that the rest of the atom was mostly empty space.

PLANETARY OR RUTHERFORD MODEL

Proposed by Niels Bohr in 1913 • Modification of the Rutherford Model • Each orbit has a corresponding amount of energy Electronics Engineering

BOHR MODEL

depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar in structure to the solar system, but with electrostatic forces providing attraction, rather than gravity.

BOHR MODEL

The _______ model is a quantum-physics–based | modification of the Rutherford model.

BOHR

In Bohr's model, energy levels are _________. | Only specific discrete energy levels are possible.

QUANTIZED

When electrons orbit the nucleus in more distant | orbits, they have ______ total energy.

The lowest energy level is the _____ state, and higher energy levels are the first, second, etc., ______ states.

GROUND, EXCITED

There are fractional energy levels. TRUE OR FALSE

FALSE

Electrons can jump up or down between energy levels, but can have energy values between the allowed energy levels. TRUE OR FALSE

FALSE (CAN HAVE)

Discovered by Sir Joseph John Thomson in April | 30, 1897

ELECTRONS

Discovered by Ernest Rutherford in 1919

PROTONS

Discovered by Sir James Chadwick in 1932

NEUTRON

Has a mass approximately equal (but slightly heavier) to that of a proton but has no electric charge

NEUTRON

``` MP = ____ME MN = _____ ME ```

1837,1839

Equal to the number of protons in the nucleus, which is the same as the number of electrons in an electrically balanced (neutral) atom

ATOMIC NUMBER

Equal to the sum of the number of protons and | neutrons of an atom

ATOMIC MASS

Each orbital shell must be filled with a | maximum number of 2n2 electrons

2N^2

Loose electrons found in the outermost orbit of an | atom

VALENCE ELECTRONS

Indicate how easily the atom can gain or lose | electrons

VALENCE ELECTRONS

A substance, body or material which has more | electrons that are free to move.

CONDUCTOR

the released electron dislodged from its original shell due to absorption of energy

Free Electron

the term used to refer to the vacancy left by free electron when it departs from its original shell; it usually behaves like a positive charge since it can attract and capture electron in the immediate vicinity

HOLE

A substance, body or material which has a characteristic that is extremely opposite to that of a conductor with more than four valence electrons but ideally, it has ______valence electrons.

INSULATOR, 8

the term for eight valence | electrons because they are tightly held by the atoms

Bound Electrons

A substance, body or material which has a characteristic in between a conductor and insulator, and has four valence electrons.

Semiconductor

A semiconductor in its pure (intrinsic) state is | neither a good conductor nor a good insulator. T OR F

TRUE

The most common single-element | semiconductors are _______

silicon, germanium and | carbon.

Compound semiconductors such as | _______are also commonly used.

gallium arsenide

Threshold Voltage OF SILICON

0.7v

Threshold Voltage OF germanium

0.3v

The farther the electron is from the nucleus, the | _____is the energy state, and

higher

any electron that has left its parent atom has a_____energy state than any electron in the atomic structure.

higher

It is the energy difference between the | conduction band and valence band.

ENERGY GAP

It is the energy required to move or transfer a valence electron at the valence band to the conduction band

ENERGY GAP

EG OF INSULATOR

Eg >5eV

EG OF CONDUCTOR

Eg = 0 V

Eg of silicon

Eg = 1.1 eV

Eg of Ge

Eg = 0.67 eV

Eg of GaAs

Eg = 1.43 eV

``` Also known as electrical potential difference, electromotive force (emf) or electric pressure ```

VOLTAGE

VOLTAGE IS NAMED AFTER ___

ALESSANDRO VOLTA

It is defined as the quantitative expression of the potential difference in charge between two points in an electric field.

VOLTAGE

The greater the voltage, the LOWER the flow of electric current through a conducting or semiconducting medium for a given resistance to the flow. Electronics

FALSE

CURRENT IS NAMED AFTER ____

ANDRE MARIE AMPERE

It is the flow of electric charges.

CURRENT

It is defined as the quantity of charge carriers | that pass a fixed point per unit of time.

CURRENT

RESISTANCE IS NAMED AFTER ____

GEORGE SIMON OHM

It is the quantitative expression of the opposition to | the passage of an electric current through a conductor.

RESISTANCE

It states that the current through a conductor between two points is directly proportional to the potential difference across the two points, and inversely proportional to the resistance through it.

Ohm’s LAW

Also colloquially known as Wattage

POWER

It is the rate at which electric energy is transferred by | an electric circuit.

POWER

The real measure of electric shock’s intensity lies in the amount of ______ forced through the body, and not the voltage.

CURRENT

Any amount of current over ____ milliamperes is capable of producing painful to severe shock.

Currents between ____mA and ___ mA ) are LETHAL! Electronics

100, 200

The liberation of electrons from an electrode into the surrounding space, usually under the influence of heat, light, or a high electric field.

Electronic Emission

It is the force that restrains the emission of | electrons.

Potential Barrier

It is the process of emitting electrons by supplying | heat energy.

Thermionic Emission

It is the process by which charge carriers, such as electrons, move over a surface or over a potentialenergy barrier by applying thermal energy in order to overcome the binding potential of the material.

Thermionic Emission

In ________, electrons gain sufficient energy to escape from the metal electrode and become free electrons. Electronics

Thermionic Emission

It is the process of emitting electrons wherein the energy of light radiation falling upon the metal surface is transferred to the free electrons within the metal and speeds up sufficiently to enable them to leave the surface.

Photoelectric Emission

In Photoelectric Emission, the emission of electrons is dependent on the _______ striking the metal surface. Electronics

intensity of light

A strong electric field set up by a high positive | voltage pulls the electrons out of the cathode surface.

Field Emission

When a high-speed electron strikes a metallic surface they give up their kinetic energy to the electrons and atoms which they strike.

Secondary Emission

Bombarding electrons collide with the electrons in the metal consequently ejecting them out of the surface. what type of emission is this?

Secondary Emission

It is also known as “electron | tube”.

VACUUM TUBE

Vacuum tube is an electronic device which consists of an ______ structure enclosed in a _______ or _____ container that is evacuated.

ELECTRODE | GLASS OR METAL

It is the flow of current through a laboratory vacuum, between two metal wires, one of which is heated.

EDISON EFFECT

The current flows only when the heated wire is______ because it is carried by free electrons released from the wire by its heat.

more negative,

It is the principle behind vacuum tubes.

EDISON EFFECT

VACUUM TUBES CONTAINS TWO PARTS. IDENTIFY THE PARTS

CATHODE AND ANODE

the electrode that emits electrons

CATHODE

the electrode that collects the emitted electrons

ANODE/PLATE

has a positive potential applied with respect to the cathode, so that the emitted electrons are attracted to provide plate current

ANODE/PLATE

``` After the tube is assembled, _____ is exhausted from the envelope (vacuum). ```

AIR

Among the methods of electron emission, ______ emission is most commonly used in vacuum tubes.

THERMINOC

MENTION THE 4 TYPES OF EMISSION

THERMIONIC, PHOTOELECTRIC, FIELD, SECONDARY

electric current is applied to a filament wire, which also serves as the cathode; the emitter is usually made of either tungsten or oxidecoated material

DIRECT HEATING

the cathode is electrically | heated by a separate heater element located inside it

IDIRECT HEATING

changes its ac input to pulsating dc output

Rectifier

generates ac output from its power supply, | without any ac input signal

Oscillator

amplifies its input signal

Amplifier

give the uses of vacuum tubes

amplifier, rectifier, oscillator

invented by J.A. Fleming in 1904

DIODE

DIODE IS ALSO CALLED AS

Fleming Valve or Thermionic | Valve

simplest type of vacuum tube that consists of two metal electrodes: the plate/anode and the cathode

DIODE

Electrons are emitted from the cathode by | supplying heat either directly or indirectly. WHAT TYPE OR VAUUM TUBE

DIODE

IN A DIODE, During the heating process, a cloud of free electrons called ______ is formed near the cathode.

SPACE CHARGE

in forward biased, the vacuum tube diode acts like | a ____ switch or a ____ circuit.

CLOSED, SHORT

if the voltage at the plate is made negative with respect to the cathode, free electrons are pushed back to the cathode and no current flows, like an open-circuit.

REVERSED BIASED

By applying a positive voltage to the plate with respect to the cathode, the free electrons repelled by the cathode are attracted towards the plate.

FORWARD BIASED

Due to the nature of the vacuum tube diode to conduct current in a particular direction and act as an open circuit when impressed with a voltage of the other direction, it is used as a ____

rectifier

It is the minimum point at which the tube no longer operates. Below, this value, no plate current flows.

cutoff point

it is the maximum point wherein raising the plate voltage no longer increases the plate current

Saturation Point

It was invented by Dr. Lee De Forest in 1906

triode

another term for triode

De Forest Tube.

It is a device that provides amplification and it is | considered as the first amplifier.

triode

It is similar in construction to the vacuum tube | diode except that a third electrode, called _______, is placed between the cathode and the plate.

triode, control grid

current in the _____ could be controlled by adjusting the grid potential with respect to the cathode.

triode

This device was found to be capable of amplifying | small signal voltages

triode

The potential applied to the control grid is usually a ______ voltage with respect to the cathode.

small negative

The grid voltage is usually made ____ so | that it cannot attract electrons.

negative

The function of the _______ is not to provide current but to have its voltage control the plate current.

CONTROL GRID

``` number of electrons at the grid is equal to the number of positive charges at the plate, hence ________ ```

NO CURRENT WILL FLOW

Less negative grid voltage ______ the plate | current.

increases

More negative grid voltage ______the plate | current.

decreases

If the grid voltage is made negative enough, there | WILL BE OR NO plate current even with the plate positive.

NO PLATE CURRENT

The ability of the ______ to vary the plate | current makes the triode amplify small AC signal.

CONTROL GRID

Any two conductors in space have a capacitance between them. Thus, a capacitance exists between each pair of electrodes in a vacuum tube.

INTERELECTRODE CAPACITANCES

They are also called stray or parasitic | capacitances.

INTERELECTRODE CAPACITANCES

The addition of another grid, called _______, | reduces the grid-to-plate stray capacitance.

screen grid

The screen grid is placed between the ______and the ____and is close to the_____

control grid, plate, plate

It is not used to control the plate current but has a steady positive dc voltage to help accelerate electrons to be collected by the plate.

control grid

______ emission occurs in tetrode

Secondary

``` It is simply a vacuum tube tetrode with an additional electrode called the _______ inserted between the screen grid and the plate to overcome the undesirable effects of secondary emission. ```

pentode, suppressor grid

Usually, the suppressor grid is connected | internally to the _____

cathode

first electronic generalpurpose | computer

Electronic Numerical | Integrator and Computer

Disadvantages of Vacuum Tubes

Bulky - High power consumption - High operating voltages required - Less suitable for portable products