NCATT AET
Rules for series circuts
1. sum of all voltage drops is equal to total voltage 2. current is common 3. Sum of all resistances is equal to total resistance 4. Sum of all power is equal to total power
Batteries store
DC power
A capacitor can block
DC voltage
Mutual inductance is measured in
Henrys
You must be aware of which lead is more negative than the other
To read the voltage drop across the resistors
Electrons travel
at the speed of light
An AC generator does not require
burshes and commutators to work
Voltage drop can damage
electric motors
Voltage
electric potential energy per unit charge measured in joules per coulomb
Q and the bandwidth are
inversely proportional
Diode
only lets current flow one way
Period
the time required for one cycle of AC to occur
Germanium diodes have a forward voltage of
.3 volts
Silicon diodes typical rating
.7 volts
With silicon diodes the forward pressure is
.7 volts
What is the equation for RMS Voltage
.707 multiplied by peak voltage
The RMS value
.707 of the peak value
the formula for Capacitve Reactance
1 over 2 pi multiplied by frequency multiplied by capacitance
Semicondcuter material is pure to what specification
1 part in 10 billion and may have impurities added at approximately 1 part per 10 million to increase the number of carriers
Procedure for solving parallel circuits
1. Draw the circuit diagram 2. State the values were given and the values to be found 3. Select the equations to be used in solving for the unknown quantities based upon the known quantities 4. Substitute the known values into the equation you have selected and solve for the unknown value
Three alternative methods to calculate resistance in a parallel circuit
1. Reciprocal of the reciprocal 2. Product over the sum 3. Rt=R (branches) over number of branches
Five rules of magnetic lines of flux
1. They take the most direct path 2. They never cross 3. Travel from north to south 4. Only pass through permeable material 5. Opposites attract, likes repel
What is the equation for peak voltage
1.414 multiplied times RMS voltage
One Watt equals
1/746 horsepower
Effective value of household AC
115 Vac
How far apart are phases in aircraft
120 degrees
Peak voltage for househould AC
165 Vac
Zener voltages range of error
5 to 10 percent
In Europe, the standard power line frequency is
50 Hertz
Coluomb is equal to
6.28 billion-billion electrons
In the USA, the standard power line frequency is
60 hertz
Power points are at
70.7% of peak power
Angle Notation
A vector with magnitude
Transformer process description
AC voltage is inducted in the unpowered secondary coil equal to the AC voltage across the powered primary coil multiplied by the ration of the secondrary coil turns to primary coil turns
Stores energy
An instructor's magnetic field does this
P type material form the
Annode with holes
Wheatstone Bridge construction
Arranged in a square four resistors, two that have a fixed or equal value on top, on the bottom one is equal to the top resistors and one has a variable value. The corners are connected to electrical source with a galvanometer connected across the opposite corners. The variable resistors is connected until the galvanometer reads zero. Thus showing the ratio of the variable resistor and its neighbor is equal to the ratio of the unknown resistor and its neighbor
Inductance is the opposite of
Capacitance
Only stores electrons
Capacitors can't produce electrons, instead they
Dampening wave
Each cycle of a tank circuit a little bit of energy is lost so over time the amplitude of the sine wave will steadily decrease
Good Insulators
Elements that don't give up valance electrons no matter what force is applied
Examples of insulators
Glass, Mica, Silica
Ohm's Law
I= V/R, Current is equal to Voltage divided by resistance
Kirchoffs Current Law is also known as
Kirchoffs first law, Kirchoffs point rule, Kirchoffs junction rule and Kirchoffs first rule
Kirchoffs Voltage Law is also known as
Kirchoffs second law, Kirchoffs Loop Rule, Kirchoffs Second Rule
Electron donors are also known as
N-type dopants
Four factors that control capacity of an inductor
Number of coils, material of the coils wrapped around the core, cross sectional area of the coil, and the length of the coil
Impedance and Inductance reactance caused by inductors in an AC circuit is referred to in
Ohms
Ideal reistors
Ohms law resistors that cannot exist in the real world but are close enough to reality to be useful
Good conductors
Only those elements that dont hang on to their valence electrons
In order to determine the total impedance
Reactance and resistance are required
RCL stands for
Resistor, Capacitor, and Inductor
Pure waves
Square, triangle, or saw tooth voltage/current wave forms that real life often distorts
The reason oscilloscopes are so accurate in capturing the crests of the waveform
The fast action of the cathode ray tube in response to changes in voltage
Choke inductor
Uses an inductor to change the output of the ripple voltage that would begin to flatten the peak voltage
In ELI the iceman, ELI means
Voltage (E) in an Inductive Circuit (L) leads Current (I)
Best known bridge circuit
Wheatstone Bridge
Mutual inductance
When an emf is produced in a coil because of the change in current in a coupled coil
The peak voltages are reached only for an instant
Why would a power calculation based on peak values be incorrect
Impeadance is symbolized by the letter
Z
Circuit impedance is symbolized as
Z with Hpp subscript
Zener diodes are maunfactured with
Zener voltages ranging anywhere from a few volts to hundreds of volts
A rotary inverter is nothing more than
a DC motor driving an AC generator
Symbol for RMS
a V with a RMS subscript
Symbol for peak voltage
a V with a peak subscript
Watt
a basic unit of electrical power that is the product of voltage multiplied by current
Chemical reactions
a batteries method of producing electrons on one terminal and absorbing elections on the other terminal
Peak voltage is not a good measure of
a circuit's voltage since most of the time it is less than that
One watt is produced when
a circut that has one amp of current flowing under a pressure of one volt
Wye connected winding does not contain
a closed loop in which parasitic currents can flow preventing such losses
Having a current waveform 90 degrees out of phase with the voltage waveform creates
a condition where power is alternately absorbed and returned to the circuit by the inductor.
Resonance
a condition where the capacitive and inductive reactance of an LC circuit are equal
Q in a circuit is
a description of the quality of the circuit
A semiconductor is
a device that only conducts electricity part of the time
Inverters
a device that performs the opposite function of converting DC to AC power
A bleeder resistor provides
a discharge path for the capacitor preventing a possible shock after the equipment has been turned off
A bleeder resistor also provides
a fixed load no matter what equipment is connected to the power supply
Magnetism describes
a force that can influence the flow of electons
A birdge circuit is a type of rectifier known as
a full wave rectifier
The circle with the wavy line inside is
a generic symbol for any AC voltage source
A capacitor is like
a little battery
lators
a material or device used to prevent the passage of heat, electricity or sound from one medium to another
Magnetic permeability
a measure of ease that lines of magnetic flux travel through a material
Protons contain
a positive electrical potential
Bandpass is expressed as a
a range of the powerpoints between high and low
When a pure AC waveform is sent to a bridge rectifier circuit the output is
a ripple voltage
In a DC circuit, an inductor is
a simple coil of wire
Zener diode
a special type of diode that can handle breakdown voltages without failing completely
A lamp connected to a 6 volt RMS AC supply will supply the same amount of brightness as
a steady 6 volt DC supply
A square wave could be produced by
a transitor acting as a switch
Thermistors are represented by
a zig zag line with a line moving through diagonally and ending in a flat line
Potentiometers are represented by
a zig zag line with a perpendicular to an arrowed line
Rt=R (branches) over number of branches
accomplished by putting the value of the resistance branched over the numbers of branches
Coluomb is the
actual count of electrons in a unit of measure
Total capacitance reactance in a parallel circuit is found by
adding the inverse sums, product over methor or the value divided by the sum of branches
Protons positive charge
affect the orbits of the electrons
Kirchoffs Current Law
algebraic sum of the current flowing away from any point in an electrical circuit is equal to the sum of the current flowing to that point
You can apply Ohms law only if
all terms are representative of their respective quantities between the same two points in the circuit
Practical average of points means
all values assumed to be positive
Sine-Wave
alternating current waveform that is produced by a rotary generator
Joule
amount of electrons in a suspended state as compared to some electrons in an adjacent part of the circuit
I is the symbol for
amps
A static inverter produces
an AC waveform using solid states devices
The symbol capacitive reactance is
an X with a c subscript
P type seminconductors are doped with a trivalent impurity and have
an abundance of free holes
Impedance
an electrical characteristic of a conductor when an alternating current is applied
Static Electricity
an electrical charge that may be built up on a non-conductive surface by friction
A capacitor
an electrical component used to store electrical energy in the form of an electrostatic field
Rectifier
an electronic devise that convers AC voltage to a type of DC
Schottky Diode
another diode that does operating in both forward bias and breakdown
The familiar battery symbol is a generic symbol for
any DC voltage source
A dielectric can be
any non conductive substance
180 degrees is the most that
any vector can be out of phase
Loads slow current by
applying resistance
Electronic meters specifically designed for RMS measurement
are best for measuring RMS
Phase angle
are differences between two similiary vary quantites (sine waves)
Reistors
are electrical devices that manage the flow of current through a circuit by creating a drop in voltage between two points
Surface mount resistors
are marked numerically and their value is obtained by consulting technical data
Henrys and Farads
are opposite of one another
Both reactance and resistance
are required to determine impedance
The devices in a circuit
are the source for each type of wave
Impedance half power points
are the two points on the impedance curve that are 70.7% of the peak impedance value
Parallel circuits
are those that offer several paths for current flow
A half wave rectifier can be something
as simple as a single diode placed on an AM radio signal
Average value of a waveform
average the values of all the points on a waveform's graph to a single aggregate number mathematically
Four methods of resistor identification
axial color code, part number, base color code, direct measure
Q is a ratio of the
bandwidth to the peak current curve
Coulomb
basic unit of electrical quantiy
Volt
basic unit of measure of electrical pressure
Power factor interest engineers
because it represents the efficiency of the system
Analog meter movements will work for RMS measurements so long as they have
been calibrated for RMS figures
When forward biased, a Zener diode
behave much the same as standard rectifying diodes. They have a forward voltage drop that follows the diode equation and is about to .7 volts
Materials used in a capacitor
best suit the capacitors function
Wire wound resistors are typically ranged
between 5 and 200 watts
A diode is added to AM systems to
block out all the negative values
A capacitor's electrical property
blocks DC voltages and passes AC voltages
Capacitance Reactance is symbolized
by a capital X with a C subscript
Capacitive reactance is symbolized
by an X with a c subscript
Inductive reactance is symbolized
by and X with an L subscript
You can determine the frequency in Hertz
by measuring the period on the wave on the horizontal axis of the oscilloscope screen and reciprocating that time value in seconds
Air
can be a good insulator but will spark when enough electrical force is applied
Secondary batteries
can be recharged because the application of a voltage can release the electrons back into solution
Bridge rectifier
can be recognized by the square arrangement of the diodes in a sort of diamond with current given two paths to flow depending on the polarity of the input signal
Half-power points, bandwidth, bandpass, and circuit quality
can only exist in a circuit operating at one resonance frequency
Maximum impedance
cancels out the signal entirely
Reactance arises from
capacitance and inductance within a circuit
If X < 0 it is
capacitive
Filter circuits used in power supplies are of two general types
capacitor input and choke input
A sawtooth wave could be produced by
capacitors or inductors
If the frequency increases then
capacitve reactance will decrease
Reactance is present in addition to resistance when conductors
carry alternating current
N type material from the
cathode with free electons
Flashover
caused by brief spikes of voltage irrespective of time
Nucleaus
center of the atom
The inductor opposes
changes in current to provide smoother output for the load
A high frequency alternating current
changes more rapidly than a low frequency one
Pi filter
combination of the simple capacitor input filter and the choke input filter
In a parallel circuit, voltage is
common through each of the branches
Bridge Circuit
contains four impedances or resistances that form a square
The value of an AC voltage is
continually change from zero up to the positive peak, through the negative peak and back to zero again
Reactive power is the sum of
current and voltage used by the inductive and capacitive reactance in a circuit
A Magnetic Field is built when
current first starts flowing through a coil
ICE stands for
current leads voltage
Inductance causes
current to lag voltage in phase
Capitance causes
current to lead voltage in phase
Faraday's Law
current will flow in a circuit provided there is electrical difference in potential and there is a path for it to flow
First rule of resistance
current will take the path of less resistance
As reverse bias increases, capacitance
decreases, the maximum voltage that a varactor diode can withstand is determined by its maximum capacitance level
First use of the diode
demodulation of amplitude modulated radio broadcast
Full wave center tapped rectifier
depending on where the load is tapped, the output is a ripple dc voltage which allows for an inversion of the signal
Symbols orientation is important to
determine the flow of current
What determines whether the vector is positive or negative is
determined if the circuit is more capacitate reactant or inductive reactant
the closest element electrically to the rectifier
determines the basic type of filter being used
Nitrogen and phosphorus are N type dopans for
diamond
Dielectric
dictates what type of capacitor it is and what it is best suited for
IFSM
diode, maximum (peak or surge) forward current
VR or VDC
diode, maximum DC reverse voltage
IF(AV)
diode, maximum average forward current
VF
diode, maximum forward voltage
VRRM
diode, maximum repetitive reverse voltage
PD
diode, maximum total dissipation
TJ
diode, operating junction temperature
TSTG
diode, storage temperature range
rectifying property
directionality of current flow most diodes exhibit
Power factor is the ratio of
dissipated power over input
To determine the total inductive reactance in a parallel circuit
divide one by the sum of the individual inductive reactances after dividing one by them
In the reverse bias mode, Zener diodes
do not conduct until the applied voltage reaches or exceeds the zener voltage at which point the diode can conduct substantial current and in doing so twill try to limit the voltage dropped across it to that Zener voltage point
Resistors are used for
drop voltage in a circuit and control voltage to obtain a particular outcome
In series parallel cicuits,
each section needs to be worked to its simplest elements then reworked to fill in the unknowns
Conductors
easily permit the movement of electrons from an electrical source to a load and back to the electrical source with a minimum of resistance
When the current is flowing in the forward bias direction then the
effective resistance is near zero
The RMS value is the
effective value of a varying voltage or current
Unless otherwise specified all values of AC voltage are considered
effective values
Reactance produces a phase shift between
electric current and voltage in the circuit
With AC it is possible to build
electric generators, motors, and power distribution systems that are far more efficient than DC
Resistance is
electrical opposition to the current flow in a conductor
Direct Current
electricity flowing in a constant direction, possessing a voltage with constant polarity
Transformer operation depends on
electromagnetic induction between two stationary coils and a magnetic flux of changing magnitude and polarity
In a diode
electron current only flows in one direction
simple triangle with a straight line
electronic symbol for a diode
Henries = (4 x PI x #turns x #turns x Coil Area x MU)/ (coil length x 10,000,000)
equation for calculating the number of heneries in an inductor is
Current is divided in a parallel circuit
evenly between the branches
Mica, ceramic, cellulose, porcelain, Mylar, Teflon, Air
examples of dielectrics used in capacitors
Applying a voltage to the N type material does what
excites the free electrons that quickly fill the holes in the P type material
Step up transformers
fewer turns in the primary winding than in the secondary winding the secondary voltage will be higher than the secondary circuit
Step down transformers
fewer turns in the secondary winding than in the primary winding, the secondary voltage will be lower than the primary
During conductance an extra valence electron
flows into the next atoms valance orbit
Rugged diodes are especially useful
for HF radio waves
Typical aircraft generators only have
four wires on the output of the busses
N type donor impurity creates
free electrons
The reactance is proportional to the
frequency
Current flows
from a negative electrical potential to a positive one
Sine waves rise and fall
from peak back to zero
Most semiconductors are constructed of either
germanium or silicon or some similar crystalline type material
The reactance of a capacitor
goes down as the frequency increases
Semiconductor materials are produced by
growing them in round tubes that are etched and doped with impurities to give them their semiconducting properties
Types of rectifiers
half wave and full wave
Thermistor
has a lower resistance at higher temps
LDR or Light Dependent Resistors
have lower resistance where there is more light
General purpose oscilloscope
have the ability to display voltage from virtually any voltage source plotted as a graph with time as the independent variable
Delta connected windings can allow
high frequency parasitic electrical currents to circulate entirely within the motor
AC is used predominately for
high power applications
Wye configuration gives
high torque at low rpm, but not as high top rpm
The attraction of opposite charges
holds the electron in its orbit
P type acceptor impurity creates a
hole, a positive charge carrier
Each component produces
impedance in the circuit that is a resistance to current flow
Exactly 180 degrees out of phase
impedance is very high
Resistance is measured
in Ohms and uses the omega symbol
Voltage is common
in a parallel circuit
DC equivalent and equivalent are sometimes used
in place of RMS
Radio waves are generated
in radio frequency ranges RF
The choke input filter uses an inductor
in series with the load resistor
Neutrons are not involved
in the conduction of electricity
Bridge Circuit is a type of electrical circuit
in which the current in a conductor split into two parallel paths and then recombines into a single conductor thereby enclosing a loop.
The width of a varactor diodes depletion region
increases and decreases via changing the level of the diodes reverse bias
If the frequency increases, the inductive reactance
increases proportionally
Capacitance is the opposite of
inductance
If X > 0 the reactance is
inductive
Circuit quality equation
inductive reactance divided by resistance
The significance of power factor lies
int he fact that utility companies supply customers with a volt amperes but bill them for watts
Third color band
is a power of ten multiplier or the number of zeros that must be added to the first two numbers
Fourth color band
is a resistors tolerance
Inductive reactance
is associated with the vary magnetic field that surrounds a wire or a coil carrying a current
Total capacitance reactance in a series circuit
is determined by adding the values of the of the individual capacitve reactances together
The sum of all the voltages around the loop
is equal to the applied voltage
The instantaneous voltage across a wire coil
is equal to the number of turns of that coil around the core, multiplied by the instantaneous rate of change in magnetic flux linking with the coil
The voltage of a capacitor in a parallel RCL circuit
is equal to the voltage at the inductor
A bleeder resistor
is found in practically all power supplies
Fundamental significance of a transformer
is its ability to step the voltage up or down from the powered coil to the unpowered coil
Electron's charge
is negative
The difference in produced polarity from the 90 degree position from the 270 degree position
is opposite
Magnetism
is the ability of a magnet to attract certain materials containing iron and other ferrous material
Effective Voltage
is the amount of AC that produces the same amount of heat as a corresponding value of DC
One Henry
is the amount of inductance a current change of one amp per second induces a voltage of one volt
The only resistance to current flow across a diode
is the amount of voltage it takes to push the diode into forward bias
When dealing with measurements of electric power, RMS amplitude measurement
is the best way to relate AC quantities to DC quantities
Capacitive Reactance
is the capacitiors opposition to change in the AC voltage
Root Mean Square
is the effective value of sine wave alternatin current
EMF
is the force required to cause one amp of the current of flow through one ohm of reistance
Electromotive Force
is the force required to move an electron measured in volts
Reactance
is the imaginary part of electrical impedance, a measure of opposition to a sinusodial alternating current
Capacitance Reactance
is the opposition to current flow in a circuit that is produced by a capacitor
Voltage Drop
is the reduction in voltage in an electrical circuit between the source and load
Rules for calculating resistors in an AC circuit
is the same as DC
In a parallel circuit the total current load
is the sum of the currents in the banches
In phase impedance
is very low
Counter or Back EMF
is voltage applied to a conductor that opposes the applied EMF
When transmitting electrical power over long distances
it is far more effecient to do so with stepped up voltages and stepped down currents and then step the voltage back down and the current backup for the industry business or consumer use
When an AC motor produces a pure sine wave
it will need to be conditioned to be useful in DC circuits
capacitor input filter will
keep the output voltage at a higher level compared to a choke input
The speed of rotation combined with electrical potential
keeps the electrons in their orbits
Varactor Diode
known as varicap diodes are a simple electronic component
One ohm
limits the flow of current to one amp under a voltage pressure of one volt
Motor with windings in a delta configuration gives
low torque at low rpm, but can give high top rpm
A battery is a device
made of one or more individual electrochemical cells used to store chemical energy and make that every available in chemical form
When an AC voltage is applied to the primary coil it creates a
magnetic flux in the core, which induces AC voltage in the secondary coil in phase wit the source voltage
Around magnets are
magnetic flux lines that travel from the north end of the magnetic to the south
First two inner orbits
make up the atomic number for the element
Complex Impedance
may be used interchangeably with impedance because impedance is a complex quantity
A bridge circuit was originally used for
measurement purposes
Capacitors are typically measured in
micro farads
Wye winding is normally
more effecient
Four band identification
most common used color coding scheme on all resistors
in electronics, varactor diodes are
mostly utilized as voltage controlled capacitors
P type material has only holes and cannot
move free electrons
Reverse breakdown voltage and breakdown voltage is typically
much much greater than forward voltage
Product over sum
multiply the individual resistances then divide that product by the sum of the resistances
Kirchoffs voltage law describes how the algebraic sum of all voltages in a loop
must equal zero
Current flows from
negative to positive
Neutrons are
neutral subatomic particles
N type dopants includes elements such as
nitrogen, phosphorus, arsenic, and antimony
180 degree position
no lines of flux are being cut by the conductor and the voltage and current are at zero
Static electricity serves
no useful purpose in aviation and cost millions of dollars in damage every year
400 Hertz
normal AC frequency for aircraft use
AC from generators used for power are
normally at realatively low frequencies
Pure silicon or germanium by themselves are
not particularly good conductors and in their pure state are insulators
Capacitance is the ratio
of charge impressed on a given conductor
Cathode bar
of the diode symbol corresponds to N type semiconductor
Air dielectric
often used in radio turning circuits
Magnetic permeability is based
on the ratio of magnetic flux density in a substance to the magnetizing force that produces it
Primary batteries
once expended cannot be recharged
Tank circuits have how many frequencies that they will oscillate at
one
At resonance, a tank circuit will operate as
one component
Physically a tank circuit is
one inductor and one capacitor wired in parallel
Resistance does what
opposed or slows down another force, drops, voltage and consumes power
No other current will flow as long as a circuit is
oscillating
Reactance
part of electrical impedance, a measure of opposition to a sinusoidal alternating current
When rating insulators for service in high voltage AC applications
peak voltage measurements are the most appropriate because the principal concern here is insulator flash over
An oscilloscope is the best way to
perform peak and peak to peak measurements
Reactive Power
phantom power that is a result of the voltage and current used by the instructors and capacitors in an AC circuit.
Frequency is equivalent to
pitch
Intrinsic semiconductor materials are
poor conductors
90 degree
position at which the most positive current and voltage are produced
Protons
positively charged subatomic particles
Ripple is the amplitude excursions from
positve to zero and black, of a waveform from the pure DC value the alternating component of the rectifier voltave
Supercapacitors
power electric and hybrid cars
Apparent Power
product of effective voltage and effective current that is expressed in volt amps rather than watts without reference to phase shift if any, between voltage and current
Polyphase
production of two or more phases of AC or of two or more alternating voltages of the same frequency
Atoms are made up of
protons, neutrons and electrons
if X = 0 then the circuit is
purely resistive
Diode current rises
quite rapidly for modest increases in voltage drop
Power factor
ratio of the actual power dissipated in an electrical system to the input power of volts multiplied by amps
X symbolizes
reactance
The resistance that is produced by the capacitors and the inductor are called
reactance which is impedance to current flow
The diode does what to AM signals
rectifies them, leaving a signal whose average amplitude is the desired audio signal
Atoms
represent the smallest elements that exist in nature
Magnitude
represents the ratio of voltage difference amplitude to the current amplitude
A Volt is that amount of force
required to cause on amp of current to flow through one ohm of resistance
Capacitance reactance is measured as
resistance to current flow
Impedance is the sum of resistance to current flow in
resistance, capacitance, and inductance
A bridge circuit essentially
reverses one cycle of the incoming AC signal
Two types of inverters
rotary and static
Phosphorus, arsenic, and antimony are used with
silicon
.7 and 1.4 are useful for
sine waves
Simple resistors are represented by
single zig zag line
Impedance only refers to the resistance of
sinusoidal alternating current
AC voltage changes
sinusoidally from zero to peak rather than linearly
The actual diode in a circuit may be a
small clear crystal device or a small cylindrical device with a band on one end to indicate the cathode
purpose of the power supply filters is to
smooth out the ripple contained in the pulses of DC obtained from the rectifier circuit while increasing the average output voltage or current
Depending on size and type dielectric
some capacitors are better for high frequency uses, while others are better for high voltage
Provides an excellent analogy for relating AC concepts
sound waves, especially music
Problems involved with using brushes
sparking, heat, and wasted energy
ECG
special purpose oscilloscope expressly designed for medical use
As a varactor diode's voltage increases
specific energy supplies must be provided for the circuits driving the diode
Wye wound is sometimes called
star windings
AC voltage value
starts at zero, increases to its maximum positive value, then returns to zero
Batteries and capacitors both
store electrons
Zig zag line
symbol of a resistor in an electrical schematic
A full wave rectifier
takes the negative AC cycle and reverses its polarity to put it in between the positive AC pulses
The heart of an oscillator
tank circuit
Zener voltage changes slightly with
temperature
Tank cirucits store energy
temporarily
The current through a forward biased PN junction is proportional
th the raised power of the forward voltage drop
The anode arrow corresponds to
the P type semiconductor
Effective voltage of AC is
the RMS value
True power
the actual power available in an AC circuit
Doping
the addition of the desired impurity to a semiconductor
Kirchoffs Voltage Law
the algebraic sum of all the voltave drops in any closed circuit is equal to zero
A farad measures
the amount of Colombes that can be applied or stored on one side of the capacitor
Ohms law states
the amount of current flowing in a circuit is directly proportional to the circuit voltage and inversely proportional to the circuit resistance
Standard P N Diodes are rated by
the amount of current required to forward bias
A magnetic field is directly proportional to
the amount of current that flows through the conductor
Dividing the load resistance into the applied DC voltage squared
the amount of power being delivered to a DC circuit load
Phase angle refers to
the angular component of the polar coordinate representation in the context of vectors and phasors
Any capacitor or conductor's capacitance depends on varying factors such as
the area of conductive plates the dielectric constant of the insulator between the plates and the distance between the two plates
Sound is generated in an AM system by
the average value is extracted using a simple filter and fed into an audio transducer
Henry
the basic unit of measurement for induction
RCL circuits are
the basis for the operation of tank circuits inside oscillators
If the capacitance increases then
the capacitive reactance will decrease
Frequency is determined by
the capacitor and inductor of the circuit
True power is the product of
the circuit voltage and the current in phase with this voltage
DC generator construction
the coil of wire is mounted on the shaft where the magnet is on the AC alternator. Electrical connections are made to this spinning coil via stationary carbon brushes containing copper strips on the rotating shaft. This allows for constant polarity but the amplitude will vary as the rotor rotates
Purely restive circuits
the complexities of AC are of no practical consequence
Doping increases
the conductivity of a semiconductor so that it is more comparable to a metal than an insulator
At the 90 degree position
the conductor is moving the fastest and the most line of flux would be cut
270 degree position
the current and voltage is at maximum again though the conductor is moving across the lines of flux in the opposite direction
According to Kirchoffs Current Law
the current entering any junction is equal to the current leaving that junction
Ripple is defiened as
the departure of the waveform of a rectifier from pure DC
Unidirectional device
the diode
Capacitance Reactance describes
the effect that capacitance has on an AC circuit
The more rapidly the applied voltage changes in value
the faster the capacitor stores energy
First two bands encode
the first two significant digits of resistance value
Reactance is also the measure of the opposition to
the flow of alternating current caused by the inductance and capacitance in a circuit rather than by resistance
Current is
the flow of electricity that pass a given point in a specific amount of time
Inductors resist
the flow of electrons
Direct current is defined as
the flow of electrons in one direction throughout a circuit with constant voltage and current
Alternating current is
the flow of electrons that continuously changes its value in magnitude and periodically reversed direction (sine-wave)
Flywheel effect
the flowing of current between a capacitor and inductor in a tank circuit
Bandwidth is
the frequency difference between the upper and lower half power points
In fuel tank quantity gauges, the dielectric is
the fuel in the tank
The higher the frequency and the larger the inductance
the harder it is for current to flow through the inductance, it meets more opposition
If we listened to an un-rectified signal
the highs and lows of the AC signal would cancel each other out and we would only hear the static hiss
A parallel circuit is at resonance with
the impedance is at maximum and the current is at a minimum
Since the capacitor and inductor are matched value wise in a parallel RCL circuit
the impedance would be the same
Mutual inductance
the induction of a voltage in one coil in response to a change in current in the other coil
If the inductance increased then
the inductive reactance increases proportionally
Regenerative feedback
the injection of the right amount of energy into the circuit to maintain the amplitude
Unlike normal inductance, mutual inductance is symbolized by
the letter M rather than the letter L
When AC voltage is applied to a conductor
the magnetic field will expand and contract at the same rate as the applied frequency
When DC voltage is applied to a conductor
the magnetic field will remain stationary
Control of exactly when current is allowed to flow
the major difference between free electrons in a transistor and current
Peak or Crest value of an AC waveform
the measure of AC quantity from its peak heigh on a waveform graph
The more rapidly the current changes
the more an inductor resists it
By using two diodes that share a common tap at the middle of the transformer
the negative pulse is effectively inversed at the output
`Frequency
the number of cycles of AC completed in one second.
Inductive Reactance
the opposition to current flow in a circut that contains an inductor
Reactive power is also used to describe
the out of phase power associated with inductors and capacitors
The three phase describes
the output of three stator windings
RMS current measurement is the best to use because
the principal concern with current is overheating of the wire which is a function of power dissipation caused by current through the resistance of the wire
Resonance frequency is equal to
the product of one half pi the square root of the value of the inductor times the capacitor
Apparent power is
the product of the readings of an AC voltmeter and an AC ammeter
Positive and negative cycles of an AC signal cannot be heard when broadcasted together because
the rate of change of the carrier is so fast
Amplitude modulated signal has a voltage that cycles at
the rate of the carrier
Resonance operation refers to
the relationship between the total current of a circuit as compared to the total impedance
In ELI the ICE man, ICE is
the relationship of Current (I) as being in front of of leading Voltage (E) for the capacitor (C)
The diode will only allow current to flow in one direction as long as
the reverse bias voltage of the diode is not exceeded
Simple circuits involving nothing more than AC power source and resistance
the same laws and rules of DC apply simply and directly
You solve for inductive reactance in a parallel circuit
the same way you would solve for parallel resistors in a DC circuit
Inductive Reactance is proportional to
the signal frequency and the inductance
At any point in an electrical circuit that does not represent a capacitor plate
the sum of currents flowing towards that point is equal to the sum of currents flowing away from that point
To determine the total inductive reactance in a series circuit
the sum of the individual inductive reactance equals the total
Z
the symbol for Impedance
Delta configuration connects
the three winding to each other in a triangle like circuit and power is applied at each of the connections
The rate of alternation
the time it takes for a wave to evolve before it repeats itself expressed as cycles per unit time or frequency
If asked to determine impedance in a parallel cuircuit, you will need to determine
the total current in the circuit
A parallel RCL circuit is operating in resonance when
the total impedance is maximum and the total current is at a minimum
Impeadance is
the total opposition of a circuit to alternating current
Kirchoff's laws about power loss in a series circut
the total voltage drop of all resistors is equal to the total applied voltage
What makes a semiconductor possible
the type of materials and how those materials are constructed
Farad
the unit measure for a Capacitor
Hertz
the unit of measure for Frequency. One Hertz is equal to one cylce of AC per second
Bandwidth is established between
the upper half power point and the lower half power point
Henrys only describe
the value of the inductor and not the impedance the device contributes to the circuit
Second rule of series circuits
the voltage drop at each resistor will be the sum of total applied voltage
If source voltage is given in AC RMS volts
then all calculated currents and voltages are cast in AC RMS units as well
If source voltage is given in peak AC volts
then all currents and voltages are subsequently calculated regarding peak units
If a vector value is 0
then the vector is considered to be in phase
For a DC generator to produce constant voltage
there are multiple sets of coils making intermittent contact with the brushes
When the magnetic field is increasing around the winding of the inductor
there is an impedance to current because of current being used to increase the magnetic field
Once current is flowing in a diode
there is no more resistance caused by the diode
First rule of series circuits
there is only one path for current to flow therefore current equal throughout the circuit
Breakdown
this is a voltage in the negative charge that if exceeded you can damage the diode
Fixed resistors are
those whose value cannot be changed
Mechanical, Chemical, Friction
three methods used to generate EMF
Wye Wound usually describes
threes phase AC generator used on modern jet aircraft
Wye wound connects all the windings
to a central point and power is applied to the remaining end of each winding
Capacitive reactance is inversely proportional
to both frequency and capacitance
Impedance is the total opposition
to current flow of AC in an electrical circut
Usual purpose of the transformer is
to transform one voltage to another
RCL computations are used
to understand how AC voltage reacts to the various types of components
Transformer
transforms electrical energy into magnetic energy then back into electrical energy again
Rectifying diode is a simple symbol is
triangle shape against a flat line
Photo resistors are represented by
two angled and arrowed lines pointing toward a zig zag
Steel and Iron
two examples of magnetically permeable metals
Inside a capacitor
two metal plates separated by a dielectric
A capacitor is made of
two parallel conductors seperated by an insulator called the diaelectric
Symbol for capacitor
two parallel lines
the formula for inductive reactance
two pi multiplied by frquency multiplied by inductance
Out of step
two waveforms are not synchronized
Amps
unit of measure used to express the flow of electrons
Ceramic dielectric
used for high frequency purposes like antennas, Xrays, and MRIs
Mylar dielectric
used for timer circuits
Glass dielectric
used in high voltage applications
Two diode rectifier
used in power conversion
Oscilloscope
used to display changing voltage over time on a graphical screen
Peak to Peak (P-P)
value of an AC waveform measured from the total height of opposite peaks
Ohms law works becasue
values of voltage, amps, and ohms are mathematically even
Varactor diodes have
variable capacitance which is a function of the voltage impressed on its terminals
Five main types of resitors
variable, potentiometers, thermistors, photo resistors, and simple
Charge time in a simple capacitor and Pi L filter is
very fast compared to discharge time
Sine waves are values of
voltage and current that start at zeror and smoothly rise to a peak value
Adding more diodes in series would add to the
voltage drop across all of the diodes
ELI stans for
voltage leads current
A diode effects voltages in parallel circuits
voltage taken off a branch will only equal the voltage that is allowed to pass the diode
If you apply an electrical voltage to the P type material
voltage will not be able to flow
Transformers can change a higher
voltage with less current or lower voltage with higher amps
Rotary electro-mechanical generators naturally produce
voltages alternating in polarity, reversing positive and negative over time
E is the symbol for
volts
NASA uses glass capacitors for
waking up the shuttle's circuitry
Nonsinusodial wave
waveshape that does not bear a close resemblance to a perfect sine wave
If larger regulated voltages are required
we could either use more diodes in series
If we plot the average of the ripple voltage
we measure much less than the peak voltage
The direction of current being produced in the conductor can be determined by knowing what two things
what direction are the lines of flux and what direction the conductor is cutting those magnetic lines of flux
Oscillator
what produces the carrier wave in most radios
Junction
when P and N materials are bonded together
Reverse bias
when P type material has voltage applied and no voltage can flow
Forward Bias
when a diode begins to conduct current
Magnetic Field
when current flows in a conductor, a magnetic field is formed
Forward bias
when current is flowing through a transistor
Reactance can also occurs for short intervals
when direct current is changing as it approaches or departs from the steady flow
When a diode is considered a variable resistance device
when the forward bias is low then the resistance of the diode is high
In a bridge rectifier only two diodes
will be forward biased at any given time
A capacitor hooked to a battery
will charge and discharge giving the appearance of DC voltage
Total voltage used by all the resistors
will equal the total voltage applied
Circuits with a high Q
will have a narrow bandwidth
Circuits with a low Q
will have a wide bandwidth
Excessive voltage drop
will result in unsatisfactory operation of electrical equipment and energy wasted in the wiring system
Wye Wound
windings arranged in the shape of a Y
Delta wound
windings that are arranged in the shape of a triangle
If a resistor greater than 2 watts rating are needed
wire wound resistors are used
Phase angle is synonymous
with phase
The Pi filter is a capacitor input filter
with the addition of an L section filter
Concerning sine waves, the top or zero
would be where the conductor is cutting through no lines of flux
The average voltage of an AC signal is
zero because the positive and negative cancel each other out
Variable resistors are represented by
zig zag line with a diagonal angle