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CHAPTER1Hans Oersted Relationship of magnetism and electricity that served as the foundation of theory for electromagnets

Most important electrical effect is the magnetic effect

Michael Faraday Theory of electromagnetic induction

Current Carrying conductor would move when placed in a magnetic field

James Maxwell Electromagnetic Theory of light

Andre Ampere Demonstrated that there are magnetic effects around every current carrying conductor and that these conductors act

like a magnet

Kamerlingh Onnes Superconductivity

Faradays Law Whenever a conductor cuts a magnetic flux, an emf is induced in it

Faradays 1st Law The magnitude of induced emf is directly proportional to the rate of change of flux linkages

Faradays 2nd Law Whenever the flux linking a coil or current changes, an emf is induced in it

Coulumbs 1st Law Force between 2 magnetic poles is directly proportional to their strengths

Coulumbs 2nd Law Force between 2 magnetic poles id inversely proportional to the distance between them

Childs Law Current in a thermionic diode varies directly with the three halves power of anode voltage and inversely with the square

of distance between the electrodes

Wiedmann-Franz Law Ratio of the thermal conductivity to the electric conductivity is directly proportional to the absolute temp for all metals

Curies Law The magnetic susceptibilities of most paramagnetic materials are inversely proportional to their absolute temperatures

Curie-Weiss Law Law relating the M and E susceptibilities and the absolute temperature

Ewings theory of

Ferromagnetism

Theory of ferromagnetic phenomena which assumes each atom is a permanent magnet which can turn freely about its

center under the influence of applied fields and magnets

Amperes Theorem States that a current flowing in a circuit produces a magnetic field at external points equivalent to that due to a

magnetic shell whose bounding edge is the conductor and whose strength is equal to the strength of current

Right hand rule Also called corkscrew rule

End Rule If looking at any one end of a solenoid, the direction of current is found to be clockwise then the end under observation

is a south pole

Helix Rule If a solenoid is held by the right hand with the fingers pointing to the direction of the current flow, the outstretched

thumb will point to the north pole

Unit Pole A pole which when placed in air from a similar and equal pole repels it with a force of 1/4pi newtons

Magnetic Pole Point in a magnet where the intensity of the magnetic lines of force is max

Magnetic Axis Straight Line passing through 2 poles of a magnet

Dia UrUo ; aluminum, platinum, manganese, chromium, oxygen

Greatest % of materials

Ferro Ur>>1 U>>Uo ; cobalt

10^-10 m Diameter of atom

10^-15 to 10^-16 m Diameter of atomic nucleus1.1 x 10^-8 cm Diameter of Hydrogen Atom

Permeance Reciprocal of Reluctance / Analogous to conductance

Coercivity Amount of magnetizing force to counter balance the residual magnetism

Leakage Factor Ratio of flux in iron to flux in air (iba iba yung tawag sa book at sa coaching)

Intensity Magnetism The flux density produced in it due to its own magnetism

Hysteresis Lag between B and H

Ferrites Non metallic materials that have ferromagnetic properties

Air Gap Air space between magnets

Keeper Used to maintain the strength of magnetic field

Moving electrical charge Where all magnetic field originates from

Stationary Electrical Charges Magnetic field does not interact with this

Uniform Magnetic field inside a solenoid

Current Carrying Wire Loop Resembles the magnetic field of a bar magnet

North A current is flowing east along a power line. If the earths field is neglected, the direction of the magnet below it is

revolution When a wire loop is rotated in a magnetic field, the direction of the induced emf changes every

Domain Group of magnetically aligned atoms

Toroid Electromagnet with its core is in the form of a close magnetic ring

Hall effect Small voltages generated by a conductor with current in an external magnetic field

Effect which is generally used in the gaussmeter to measure flux density

Edison effect Emission of e- from hot bodies

Wiegand effect Ability of a mechanically stressed ferromagnetic wire to recognize rapid switching of magnetization when subjected by a

dc magnetic field

Wall Effect Contribution to the ionization in an ionization chamber by e- from the walls

Bridgman effect Phenomenon when current passes through an aristropic crystal, there is an absorption of heat due to the non uniformity

in current distribution

Hydrogen Simples atom to exist; it is a diamagnetic material


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Germanium 32p+, 32e- and 40n = 72Ge32 = (AtomicWeightGeAtomicnumber)

Atomic Mass Sum of proton and neutrons (di ko sure pero eto nakalagay e)

Atomic Number # of protons or # of electrons

72.6 Ge exact atomic weight

28.09 Si exact atomic weight at 300K

# of protons Determines the atomic # of an element

Copper 34n

Metallic bonding Atom bonding due to the force of attraction between groups of + ion and ion

Motor Action Physical motion resulting from the forces of magnetic field

Flux linkages = flux x # of turns

Electron Volt (eV) Customary energy unit in atomic and nuclear physics

Joule, Watt-sec, KW-h Units of electrical energy

KW-h Practical unit for electrical energy

Ion An atom or group of atoms carrying a net electrical charge

Thermionic emission Evaporation of e- from a heated surface

Amber Greek word for electron

Plasma Charged Gases

Exclusion Principle Principle that states that each e- in an atom must have a different set of quantum numbers

Pauli Exclusion Principle Principle that states that only 2 e- with differebt spins are allowed to exist in a given orbit

Radio Freq Common application if an air-cored choke

Ohms Law For linear circuits (AC,DC)

Crystalline Solid One of the solid structures in which the position of the atoms or ins are predetermined

Amorphous Solid with no defined crystal structure; also called non-crystalline

Permits mechanical

Clearance

Reason for air gaps between rotor and stator

Van der Waals Bond Formed when there exist distant electronic interaction between opposite charges present in the neighboring atoms or

molecules

Atomic Packing Factor Measures compactness of crystal = atom volume/cell volume

Madelung Constant Corrects the electrostatic forces of the more distant ions in an ionic solid

Creepage Conduction of electricity across the surface of a a dielectric

Aurora Corona discharge

1.15 to 1.25 Leakage coef for electrical machines

Astrionic Science of adapting electronics to aerospace flight

Air Has straight BH curve passing through the origin

Soft iron BH curve not straight

Using material with narrow

hysteresis loop

Reduces hysteresis loss

Silicon steel Least hysteresis loop area

Unlimited # of compounds in nature

Ohm-m SI unit for specific resistanceSiemens / Mhos SI / CGS for conductance

Siemens/m SI for conductivity

Resistivity Temperature For Conductors

2 Wb/m^2 Typical saturation flux density for most magnetic materials

insulators Temp coefficient of resistance is NEGATIVE;

Temp coefficient of resistance is directly proportional to T;

R is inversely proportional to T

semiconductors Temp coefficient resistance is NEGATIVE

conductors Temp coefficient resistance is POSITIVE;

Temp coefficient of resistance is inversely proportional to T;

R is directly proportional to T

Temp coefficient resistance Dependent on nature and temp of material

Tells how much the R changes for a change in T

+ temp coef Manganin, Tungsten Filament

- temp coef Electrolytes, carbon

.0034 Temp coef of resistance of pure gold

.0038 Temp coef of resistance of silver

.0039 Temp coef of resistance of lead

Almost 0 Eurekas Temp coefficient resistance

Silicon Carbibe Ohms law cannot be applied to this material

10x Hot R = ___x Cold R

Neutral A body under ordinary conditions

Dielectric constant or

Specific Inductive Capacity

Another name for relative permitivitty

Breakdown Volatage Another name fore Dielectric Strength (V/mil)

Magnetic conductivity Another name for permeability

1/(oo) = c2 Relationship of Eo and Uo and c (light velocity)


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1 and 10 Dielectric constant of most materials

Mica Insulating material used in an electric ion

Porcelain Insulating material used in voltage transformers

Earphones Uses permanent magnets

Motors Uses temporary magnets

CHAPTER2+ to - Conventional Flow

- to + Electron Flow

W P true power

VAR Q reactive power

VA S apparent powerPower factor Cos = P/S

Reactive factor Sin = Q/S

Voltage Magnification Factor Q Factor of Series resonant circuit

Current Magnification Factor Q factor of // Resonant Circuit

Voltage Resonance Series Resonance

Current Resonance Parallel Resonace

Ionization Current Results from free electrons

ELI Series Resonace / Acceptor Circuit

ICE Parallel Resonance / Rejector Circuit

ELI by exactly 90 deg Pure inductance

ICE by exactly 90 deg Pure capacitance

ELI by less than 90 deg RL

ICE by less than 90 deg RC

Reactance = 0 If I and V are in phase for an AC circuit

0.707 Current is ____ times the max current at half power points of a resonance curve

Gang Capacitor Variable Capacitor which the C is varied by varying the plate area

Trimmer Capacitor A variable capacitor in which C is varied by changing distance between plates

55 ohm-cm Specific resistance of pure Ge

60 ohm-cm Resistivity of pure Ge under standard conditions

55 ohm-cm Specific resistance of pure Si

Leading or Lagging Power factor of series RLC at its half power points

Leading pf Capacitive Load

Lagging pf Inductive Load

Separation of the half power

points

Meaning of BW in series RLC

Effective Value Most important value of a sinewave

Faradic current An intermittent and non symmetrical alternating current like that obtained from the secondary winding of an induction

coil

Stray Capacitance Capacitance that exists not through design but because 2 conducting surfaces are relatively close to each other

1.73 Peak factor of a triangular wave

Triangular Wave Peakiest waveform

Independent to each other Reason for // connection of appliances in homes

Appliances have different

current ratings

Reason why not in series connection of appliances in homes

Sinusoidal Most popular waveform

Square wave Most common non sinusoidal waveform

Ideal Current Source

(parallel r)

Infinite internal resistance

Zero internal conductance

Ideal Voltage Source

(series r)

Zero internal Resistance

Infinite internal conductance

Ideal Ammeter

(in series to the circuit)

R is 0

Ideal Voltmeter(in // to the circuit)

R is infinite

Resonance Curve Frequency VS Current

Reactance Chart Estimates the resonant freq and to find the reactance at any freq for any value of C or I

Edge Effect Refers to the outward curving distortion of the lines of force near the edges of 2 // metal plates that form a capacitor

The narrower the passband (For Series RLC), the higher the Q

Internal Heating Leakage resistance in a capacitor results to

Phase The_____ of an alternating quantity is defined as the fractional part of a period or cycle through w/c the quantity has

advanced from a selected origin

3.7K Metal tin becomes a superconductor at this temp

It has a varying magnetic

field

Reason why AC can induce voltage

Exponential Law Charging of capacitor through a resistance obeys _______

Sinewaves The factor 0.707 for converting peak to rms applies only to _____


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Joule Term to express the amount of electrical energy stored in a electrostatic field

Breakdown Voltage Refers to the lowest voltage across any insulator that can cause current flow

Blocks DC current Capacitor

47 ohms Preferred value of resistor (among the choices which are 520, 43K and 54K)

Electrolytic capacitor Most suited for dc filter circuits;

Highest cost per uF;

Only Capacitor used in DC circuits;

Used in Transistor amplifiers

Variable Capacitor Used air dielectric

Barium Strontium Titanite

Dielectric

Also called ceramic

Surge Voltage Max voltage that can be applied across a capacitor for a short period of time

Voltage It is used as the reference phasor for // AC circuits

It has reactance in radio freq

circuits

Disadvantage of wirewound resistors

Manganin Most common material for wirewound

Temp coef Indicated by the first band for a 5band method of capacitor color coding

Rate at which electrons pas

a given point

Determines the magnitude of an electric current

Q of 10 Means that the energy stored in the magnetic field of the coil is 10x the energy wasted in the resistance

770V Neon lamp ionizes at approx _____

Anticapacitance Switch Switch designed to have low capacitance between terminals when open

Bifilar Resistor Resister wound with a wire doubled back on itself to reduce inductance

Alloy Fusion of elements without chemical action between them

Vpeak Used in calculating max instantaneous power

Vrms Used in calculating VaveMaximum capacitance Happened when movable plates of gang capacitor overlaps the fixed plates

Thevenins Theorem Used for analysis of Vacuum tubes

Phasor Rotating vector whose projection can represent either current or voltage

CHAPTER31 # of e- in 4th orbit of copper atom

8 e- Each atom in a Si Crystal has _____ in its valence orbit

32 p+ Silicon Atom has ____

More slowly e- in the largest orbit travel _______ than the e- in smaller orbits

Intrinsic semiconductor Pure Semiconductor

Extrinsic semiconductor Doped semiconductor;

2 Ohm-cm = resistivity

2mV/C For Ge or Si diodes, the barrier potential decreases _____

Piecewise Linear Model A diode modeling circuit which considers the threshold voltage, Rave and switch as the diodes equivalent

Diffusion and drift 2 mechanisms by which holes and electrons move through a Si crystalDiffusion Random motion due to thermal agitation in the movement of h+ and e- in a Si crystal

Drift Current Happens when charges are forced to move the electric field of a potential difference

Carrier Drift Mechanism for carrier motion in semicon

Zener and Avalance Effects Two possible breakdown mechanism in PN jxn diodes

Zener Breakdown Electric field in the depletion layer increases to the point where it can break covalent bonds and generate electron-hole

pairs

Avalanche Breakdown (In semiconductors) this takes place when the reverse bias exceeds a certain value;

Happens when the minority carriers that cross the depletion region under the influence of the electric field gain

sufficient KE to be able to break covalent bonds in atoms

Avalance effect Occurs are higher reverse voltages

Diffusion or Storage

Capacitance

Is the forward bias capacitance of a diode

Lifetime Amount of time between the creation and disappearance of a free electron

Recombination Annihilation of e- and h+;

Merging of e- and h+

Transit time Time taken by e- or h+ to pass from emitter to collector

Reverse recovery time Time taken by a diode to operate in the reverse to forward condition;

Time it takes to turn off a FB diode;

= storage time + transition interval from F to R bias

Insulator At room temp, silicon acts like a ______

Compound Semicon Gallium Arsenide, Alluminum Arsenide and Gallium Phosphide are classified as ______-

Increase electric

conductivity

Purpose of adding impurities

Ptype semicon Silicon doped with trivalent impurity;

Holes are majority carriers

Ntype semicon Silicon doped with pentavalent impurity;

Electrons are majority carriers


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Trivalent Atom Acceptor Atom;

Boron, Indium, Gallium,

Pentavalent Atom Donor Atom;

Phosphorus, Arsenic, Antimony, Bimsuth

N type Forms when the # of free e- in a doped semiconductor is increased;

Forms when pentavalent atom is added

P Type Forms when the # of free e- in a doped semiconductor is reduced

Forms when trivalent atom is added

PN crystal Other name for Jxn Diode;

Commonly rated by its PIV and max forward current;

Max forward current is limited by Jxn Temperature

Dipole Each pair of + and ions at the jxn is called _____

Barrier Potential Inversely proportional to temp

High field emission Creation of free electrons through a zener effect

Intensity of electric field Zener effect depends on this

Forward current Most impt diode parameter which gives the current value a diode can handle without burning

Reverse Breakdown Voltage Maximum reverse voltage that can be applied before current surges

Esaki Diode Tunnel Diode;

Principal char is that it has negative resistance region;

Widely used in oscillators, switching networks and pulse generators

Schotty Diode Most impt application is digital computers

Shocklet Diode No depletion layer

Bulk resistance Sum of the P and N regions resistances;

rB = (V-VT)/I

VAristors Are transient suppressors

Varactor Diode Also known as epicap, varicap, voltage-variable capacitance, voltacaps;Used for tuning the Receivers and is normally operated at reverse biased

Point Contact diode Used metal cat whiskers as its anode;

Classified as hot carrier diode

PIN diode Used in RF switches, attenuators and other phase switching devices

Bulk resistance decreases in

semiconductors

If doping increases, ___________

High Resistance Lightly doped semiconductors have ____

Less than 1 ohm Typical bulk resistance of rectifier diodes

Transition region

capacitance

The reverse bias diode capacitance is termed as ______

LED Equivalent to a optocoupler ;

Typical operating current is 10mA;

Voltage drop is 1.5V;

Constructed using Gallium Arsenide;

Gives light when FB

LAD A photodiode which conducts current only when FB and is exposed to light;

Also called photodiode

IR emitters Solid state GaAs devices that emit a beam of radiant flux when FB

Optocoupler Also known as optoisolator

Second approximation (for diodes) an equivalent ckt of a diode in which it is represented as a switch series with barrier potential

Third approximation (for diodes) an equivalent ckt of a diode in which it is represented as a switch in series with a resitance

Negative voltage supplies Needed for PMP voltage divider bias

16.7 ms Halfwave signal (1/60Hz)

8.33 ms Fullwave signal (1/120Hz)

40.6% Max rectification efficiency of HW

81.2 Max rectification efficiency of FW

MOSFET Highest Zin;

Sometimes called Insulated Gate FET

FET Has least noise level;Has higher Zin compared to BJT due to its input which is reverse biased

uA Typical leakage current in a PN jxn

Ohms Resistance of a FB PN jxn

Derating Factor Shown on a data sheet that tells how much you have to reduce the power of a device

Dember Effect Or Photodiffusion effect;

The creation of voltage in a conductor or semicon by illumination of one surface

Bulk Effect Effect that occurs within the entire bilk of a semiconductor material rather than a localized jxn

Skin Effect Increases the resistance of wires at high frequencies

Anotron Diode A cold cathode glow-discharge diode having a copper anode and a large cathode of sodium or other material

BARITT Diode A microwave diode in which the carriers that transverse the drift region are generated by minority carrier injection from

a FB jxn instead of being extracted from the plasma of avalanche

Spacistor Multiple terminal solid state device similar to transistor that generates frequencies up to avout 10,000 Mhz by injecting

e- or h+ into a space charge layer


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Zener Diode Principal char is that its voltage is constant under conditions of varying current;

Used as a voltage regulator or reference voltage

Voltage multiplier Converts AC to DC, where the DC output can be greater than the AC input

Photoconductive Cell Or Photoresitive device

Emitter Resistor Most commonly used for biasing a bipolar jxn transistor

Silicon Not a good conductor;

Has the smallest leakage current

% Ripple = (Vac / Vdc) x 100

Ripple Voltage = (rZ / (rZ+rS)) x V

Holes As a general rule, _____ are found only on semiconductors;

An incomplete part of an electron pair bond;

Vacancy left by free electrons

Isotopes A nuclei with common # of p+ but different # of neutrons

Series Capacitors In power supplies, circuits that are employed in separating AC and DC components and bypass AC components around

the load are called _______

Emitter Follower Circuit Av is low and usually less than 1;

Ai is High;

input is in-phase with output;

Employs 100% negative feedback;

Used for impedance matching;

Equivalent to CC amplifier

BJT / transistors Current controlled device;

Largest region is the Collector Region

FET Voltage controlled device;

Has 5v pinch off voltage;

FET transcoductance = IC/VGS ;Square Law Devices;

At cut-off, the depletion layers are touching

Transistors Converts DC power to AC power

Power Transistors Made in large sized to disspate more heat

Power amplifiers Input is DC

Oscillators Converts DC power to AC power

Ohmic Equivalent if transistor at saturation in JFET is ______

IGFET Another name for MOSFET

CMOS Easily damaged by static charges

Saturation region Used by FET (EMOSFET) to act as an amplifier

Triode region and Saturation

Region

Used by FET (EMOSFET) to act as a switch

10uF Coupling capacitor value in RC coupling;

Coupling capacitor (Cc) must be high enough to prevent attenuation of low freq

Qpoint / OperatingPoint Point of intersection between a diode characteristic and a load line;

Intersection of dc and ac load lines

Luminous Efficacy Measure of the ability of any LED to produce lumens per applied watt of energy

Scale Current Another name is Saturation Current

Input Char Curve A graphical representation in a transistor where the IE is plotted against the variable VEB for constant VCB

Output Char Curve A graphical representation in a transistor where the Ic is plotted against the variable VCB for constant IE

RC coupling Used in low level, low noise audio amplifiers to minimize hum pick up from stray magnetic fields

Transformer Coupling Major advantage is permitting power to be transformed from the relatively high output impedance of the first stage to

the relatively low input impedance of second stage

1.12eV(Si) and 0.72eV(Ge) From these conditions, it can be said that less # of electron-hole pair will be generated in Si than in Ge

0.135 m2/V-s Electron mobility in silicon

Harold Black Invented feedback amplifier in 1928

Always points to N and away

from P

Arrows in semiconductor symbols

CE circuit Conventional amplifierJunction and Point Contact Structural category of a semiconductor diodes

Threshold Voltage Turns on an enhancement-device

DMOSFET Acts mostly as a FET;

Can operate in D and E

EMOSFET Can only operate in E

Heat dissipation Most important factor of a power transistor

Collector Efficiency Most important consideration in power amplifiers

Drift transistor Has a high frequency cut off due to its low inherent internal capacitance and low electron transit time

Poor frequency response Results when transistors are used as video amplifiers

Fission Break up of nuclei into nuclear fragments that are nuclei themselves

Neutrino Zero charge and zero mass

EG => 5eV Energy gap for insulators

EG = 1.1eV Energy gap for Si semiconductors


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EG => 0.67eV Energy gap for Ge semiconductors

Bound Electrons Tightly holds the 8 e-

25mV Thermal Voltage at room temp;

Thermal voltage causes holes in intrinsic semiconsuctors

8.62 x 10^-5 eV/K Boltzman constant

Voltage divider Bias Preferred form of biasing a FET

VGS(OFF) = VGS(ON) For N-channel EMOSFET

Beta CE gain

= IC/IB

Alpha CB gain

= IC/IE

CHAPTER5

Collector has reverse bias Reason why a transistor amplifier has high output impedance

Gain-BW product Considered as an amplifier figure of merit

Logic probe In an oscilloscope, it is used to indicate pulse condition in digital logic circuit

Logic analyzer Used to sample and display systems signal

Oscillators Produces undamped oscillations

Biasing Establishes a fixed level of current or voltage in a transistor

AF transformer It is shielded to prevent induction due to stray magnetic fields

Amplitude Distortion Or harmonic distortion

Frequency Ear is not sensitive to this

RC coupling To separate bias of 1 stage to another stage;

Used for voltage amplification;

Av is constant over mid frequencies;

Most economic type of coupling;

Not used to amplify extremely low freq because electrical size of the coupling capacitor becomes very large;

Type of coupling used in the initial stage of a multistage amplifier;

Transformer coupling Used in power amplifiers;

Provides high freq because DC resistance is low;

Used when load resistance is very low;

Type of coupling used in the final stage of an amplifier;

Introduces frequency distortion;

Most expensive type of coupling;

Provides high gain because it employs impedance matching;

Can be used either in Voltage or Power amplifiers

DC coupling Best freq response;

Used to amplify dc signals in multistage amplifier;

Achieves minimum interference in freq response

Klystron Oscillator Used in order to produce freq in the microwave region

Step Down Transformer Used for impedance matching;It is also used as the output transformer in power amplifiers

Gives distorted output Disadvantage of impedance matching

Campbell and Wagner Where the basic concept of electric wave filter originated

10Khz Freq that produces highest noise factor

Coupling Capacitor The input capacitor in an amplifier

Bigger AC load line slope is ____ then DC load line slope

At least 2 transistors Used by multistage amplifier

Generator Output level is kept

constant

To obtain the frequency response curve of an amplifier

Relaxation oscillator Type of oscillator where the frequency is determined by the charge and discharge of RC networks used in conjunction

with amplifiers or similar devices

GPS Instrument used to measure ones location in terms of coordinates

1/( 4(LC) ) Cutoff freq for constant-k high pass filter

The smaller the %VR The better!

Thin base Transistor should have a _____ to have more Av

Darlington Pair Its advantage is that it increases overall Beta Gain

Independent A feedback network is _______ of frequency

Feedback Networks They employ resistive networks

Positive Feedback Employed by Oscillators;

Negative Feedback Employed by amplifiers

Reduces distortion;

Reduces gain;

Increases BW of an amplifier;

The sacrifice factor is (1+A)

Feedback factor () Is always less than 1;

= (1/Af) (1/A)

= Vf / V


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Approx gain of an amplifier

with negative feedback (Af)

Reciprocal of feedback factor;

= 1/(A) in negative feedback Very much greater than 1 to obtain good gain stability

Power Again (Ap) = Av x Ai;

Main consideration in the output stage of an amplifier

Crossover network A pair of filter common on a high fidelity system which separates audio freq band signals into 2 separate groups

where one is fed to the tweeter and the other to the woofer

Armstrong circuit Simplest variable freq sinusoidal oscillator

10uF Typical value of Coupling capacitor

50uF Typical value of emitter bypass capacitor in a CE multistage amplifier

Re, reand Input R of CE amplifier is affected by ________

Out of phase (180 deg) Output is always _______ with the input signal in a CE amplifier

Zero Phase difference between collector voltage and signal voltage in CE amplifier

Increase Av Purpose of emitter bypass capacitor in CE amplifier is to _____

LC oscillator Used only in/for high freq

RC Oscillator Used only in/for low freq

Sine wave oscillator Composed of 1 or more amplifying devices with some freq determining networks introducing + feedback

Hartley Oscillator Used commonly in Radio Rx

Crystal Oscillator Used commonly in Radio Tx;

Fixed frequency oscillator;

Has fewer loses and will generate alternating emf longer than LC circuit when shock excited

Tuned Amplifier Operated in Class C;

Used in Radio freq

Wien Bridge Oscillator Frequency stability of the oscillator output is maximum ________;

Employs both + and feedback;

Used in signal generators in laboratories;Hum in the circuit A pulsating DC applied to the power amplifier causes ______

Low Output Important limitation of Crystal Oscillator

High Q Reason why crystal oscillator freq is very stable

More than 10,000 Typical Q of a crystal

Push Pull amplifer Commonly employed at the output stage of an amplifier

X axis Cutting perpendicular to end to end;

Electrical axis;

Connects the corners of the crystal

Y axis Cutting perpendicular to face to face;

Mechanical

+ temp coef When crystal freq increases with temp

- temp coef When crystal freq decreases with temp

Zero temp coef When crystal freq doesnt change with temp

More battery consumption Low efficiency of a power amplifier results in ______

Buffer Amplifier Used for minimum loading and minimum mismatch

Hand capacitance If you move towards an oscillating circuit, its freq changes because of the ______

Ic becomes maximum When transistor is at saturation

Maximum voltage appears

across transistor

When transistor is at cut-off

At minimum In an LC circuit, when the Capacitor energy is at max, the inductor energy is _____

AC load line The operating point in a transistor amplifier moves along ______ when AC signal is applied

Power stage Also called output stage in an amplifier

DC At zero signal conditions, a transistor sees _____ load

Sum of AC and DC The current in any branch of a transistor amplifier that is operating is the _____

CMRR = infinity For an ideal differential amplifier

To set up an operating point The purpose of dc conditions in a transistor is _____

To avoid drop in gain The purpose of an emitter capacitor is _____

Collector Supply The Poutput of a transistor amplifier is more than the Pinput due to the additional power supplied by _______

Low When a transistor feeds a load of low R, its Av is _____

25% Max collector efficiency of Resistance Loaded Class A power amp

50% Max collector efficiency of Transformer coupled Class A power amp

RF amplifiers Class C amplifiers are used as

Driver stage Employs class A amplifiers

1NPN, 1PNP transistor Complementary-symmetry amplifier

Increases Input Impedance,

Decreases Output Impedance

Negative voltage feedback

Decreases Input Impedance,

Increases Output Impedance

Negative Current Feedback

ID The Quiescent current of a FET amplifier is _____

AND gate The frequency response of the combined amplifier can be compared with an ______

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