Fundamentals of Electricity and Electronics 8078

  • Transistor Bias and Current Flow (NPN Transistor)
    • 1: Correct illustration; base is positive relative to the emitter, forward biasing the emitter-base junction, enabling base-emitter current flow and thus collector-emitter current flow.
    • 2: Incorrect; base and emitter have the same polarity, preventing emitter-base current flow, thus no collector-emitter current.
  • Transistor Bias and Current Flow (PNP Transistor)
    • 3: Incorrect; base and emitter have the same polarity, preventing emitter-base current flow and collector emitter current.
  • Current Limiter Schematic Symbol
    • Symbol 3, two triangles pointing towards each other, with a line on both sides. They are mainly for aircraft circuit/bus sectionalization.
    • Symbol 1, a triangle and Z-like symbol across a horizontal line, represents a Zener diode.
    • Symbol 2, one triangle pointing to vertical line, represents a general-purpose diode.
  • Coil Inductor Strength
    • Coil inductor strength increases as more loops are added close together.
    • Many loops close add up to a strong electromagnet.
  • Magnetic Lines of Force
    • Iron facilitates the passage of magnetic lines of force more readily than copper or aluminum.
    • Material permeability measures the ease of magnetic force lines to pass through the material.
  • Capacitor Working Voltage (AC Circuit)
    • Capacitor working voltage in an AC circuit should be at least 50% greater than highest applied voltage.
    • Working voltage is the highest voltage that can be steadily applied without dielectric breakdown, dependent on dielectric material and its thickness.
  • Capacitors in Series
    • Total capacitance of different rated capacitors connected in series is less than the capacitance of the lowest rated capacitor.
  • Capacitors in DC Circuits
    • Smoothing out pulsations in current/voltage.
    • Capacitors store electrical charges, having excess electrons and releasing them into the circuits when values decrease.
  • Capacitor Electricity Storage Factors
    • Plate area: Larger area yields greater capacity.
    • Dielectric thickness: Closer plates yield greater capacity.
    • Dielectric material: Higher dielectric constant yields greater capacity.
  • Total Capacitance Calculation (Series)
    • Example with 0.02µF, 0.05µF, and 0.10µF capacitors in series: total capacitance is 0.0125 µF.
  • Total Capacitance Calculation (Parallel)
    • Use the formula CT=C1+C2+C3CT = C1 + C2 + C3. Total capacitance is the sum of individual capacitances.
    • Example: 0.02 µF + 0.05 µF + 0.10 µF = 0.170 µF.
  • Total Capacitance Formula
    • CT=C1+C2+C3CT = C1 + C2 + C3. If three capacitors are connected in parallel.
    • Example: 0.25 µF + 0.03 µF + 0.12 µF = 0.4 µF
  • Electrical Charge Symbol
    • Q symbolizes Coulomb when measuring electrical charge.
    • Capacitance formula: C=fracQEC = frac{Q}{E}
    • C = Capacitance in farads
    • E = Applied voltage in volts
    • Q = Charge in coulombs
  • Inductive Reactance
    • Inductive reactance (XLX_L) increases with an increase in inductance and frequency.
    • Formula: XL=2upifLX_L = 2 upi fL
  • Capacitors in Parallel
    • Total capacitance is equal to the sum of all individual capacitances.
  • Inductors in Series
    • Total inductance is the sum of individual inductances.
    • Formula: L<em>T=L</em>1+L<em>2+L</em>3…L<em>T = L</em>1 + L<em>2 + L</em>3…
  • Inductors in Parallel
    • The total inductance is less than the inductance of the lowest rated inductor.
  • Electric Energy Transfer
    • Electric energy transfer without connection, is called induction.
    • Induction occurs when changing current in an AC circuit causes a changing magnetic, which induces a voltage in an adjacent circuit.
  • Impedance in AC circuit
    • Combined resistive is Impendence (Z).
    • Impedance is the vector sum of resistance and total reactance in a circuit.
    • Formula: Z=binomR2+X2Z = binom{R^2 + X^2}
    • Inductive reactance occurs when current lags voltage.
    • Capacitive reactance occurs when current leads voltage.
    • Resistance occurs when current and voltage remain in phase.
  • Inductive Reactance
    • Opposition to AC flow produced by EMF, generating back voltage.
    • Inductive Reactance is measured in ohms, the same as resistance.
    • Inductance measures a circuit's opposition to a change in current and is measured in henries.
  • Coil flow of alternating current
    • Inductive reactance (XLX_L) is the opposition provided to alternating current flow in a coil of wire.
    • Counter EMF decreases total voltage across the coil, this decreasing current flow.
    • XLX_L is measured in ohms.
    • Does not cause heat or use any power.
  • Effective Voltage in AC Circuit
    • Effective voltage is less than the maximum instantaneous voltage and is 0.707 times its peak voltage.
    • Effective voltage is the root mean square (rms) voltage.
    • Peak voltage is measured with a special peak volt-meter or an oscilloscope.
  • AC Circuit Values
    • Values for current or voltage in an AC circuit are effective values unless specified.
  • Impedance of AC-Series Circuit
    • Total reactance is the difference between the inductive reactance and the capacitive reactance.
    • In an AC circuit with inductive reactance of 10 ohms, capacitive reactance of 4 ohms, and resistance of 8 ohms, total impedance is 10 ohms.
  • Parallel DC Circuit Resistance
    • Total current is equal to the sum of the branch currents.
  • Farads to Microfarads
    • Multiply farads by 10610^6
    • Example: 2 farads = 2,000,000 microfarads.
  • Farads to Picofarads
    • Multiply farads by 101210^{12}
    • Example: 2 farads = 2,000,000,000 picofarads.
  • Electrical Power
    • Two 24-voltlights, requiring 3 amps each in a parallel system, require the most electrical power, (144 watts).
  • Correct Instrument installation
    • Out of the four instruments installed (voltmeters and ammeters), only two were installed correctly.
    • To be installed correctly, the voltmeter must be installed across the light bulb and the ammeter must in series with light bulb and the battery.
  • Voltmeter in a Circuit
    • A voltmeter is always connected in parallel with the unit to be measured.
    • Voltmeter reading across a closed switch reads zero voltage.
  • Metric prefix Milli
    • Milli ampere means 0.001 ampere.
  • Kilovolts to Volts
    • 0.002 Kilovolt (kV) equals 2.0 Volts.
  • Basic Unit of Electrical Quantity
    • Coulomb, 1 coulomb = 6.28 * 10^18 electrons.
  • Potential difference
    • Potential difference is measured by Volts.
  • Voltage drop across resistor
    • It's equal to the voltage of the source.
    • Example: Since the resistors are all in Parallel across 24 volts DC, there will be a voltage drop of 24 volts across each resistor.
  • Series-Parallel Circuit Voltage
    • Combination of series (3.0V) and parallel connections.
  • Voltage across resistor
    • Equals power source.
    • Example: 8-ohm resistor has 24 volts across it with a 24-volt battery.
  • Voltage Drop in a Circuit
    • Dependent on amperage if resistance if fixed.
  • Current Supply for Parallel Lamps
    • Total current is equal to the sum of currents flowing through each lamp.
    • Example: For five lamps in parallel (three 6-ohm and two 5-ohm), the generator provides 25.23 amperes.
  • Electron Flow Effects
    • The movent of electrons flowing in a conductor does not apply to static energy.
  • Wire Between points C and D
    • Is total current of 3 amps, which is due to the combination of two parallel resistors R<em>2R<em>2 and R</em>3R</em>3.
  • Total Current Flow
    • Total resistance of 8.57 ohms and a toal current flowing of 1.4 amps, for a 12-V circuit with a number of resistors.
  • Parallel Circuit Total Current
    • Current for each resister is the sum of current through individuals values.
    • Example with three 6-ohm resistors across a 12-volt battery has a current of 6 amps.
  • Parallel Circuit Resistance Value
    • Two resistors of equal value in parallel providing a resistance of 12 ohms, each resistor must have a resistance of twice the value, or 24 ohms.
  • Operating Resistance of a Light Bulb
    • 30-watt bulb in a 28-volt system has a resistance of 26.13 ohms.
  • Total Resistance of Circuit
    • Solved in four steps, combines resistors in parallel and series R(4−5)=4ΩR (4-5) = 4\Omega, R(2−4−5)=16ΩR(2-4-5)=16\Omega, gives the result of R(2−3−4−5)=3.2ΩR(2-3-4-5) = 3.2\Omega, and then includes R1R1 in parallel for the result of RT=21.2ΩRT = 21.2\Omega.
  • Resistance in Parallel Circuit
    • More routes for flow for less resistance.
  • Total Resistance in Parallel
    • Total resistance for resistors R2R2, R3R3, and R4R4 in parallel, then R1R1, R(2−3−4)R(2-3-4), and R5R5is series is found: RT=17ΩRT=17\Omega.
  • Conductor Resistance Decrease
    • Decrease length or increase cross-sectional area to decrease resistance.
  • Parallel Circuit Resistance Value
    • Three resistors in parallel giving 12 ohms, each resistor in three times this value, or 36 ohms
  • Open Resistor
    • If R5\R5 is disconnected, ohmmeter reads the series and parallel result is 3Ω3\Omega.
  • Disconnected Resistor
    • When R3R3is disconnected at terminal D, then the resistance if reading is infinite resistance.
  • Infinite break in resistance
    • The Ohmmeter will read the parallel resistance and give 10 ohms result.
  • Generator Power
    • Total power the generator must produce is 451 watts, given lighting and motor usage.
  • Electric Motor Power
    • At a certain voltage, motors input power required for wattage doesn't change.
    • Example, for an efficient 1 HorsePower motor would need 1,000 watts of input power at 12 and 24 Volts.
  • DC Motor Power
    When we know the HorsePower output and efficiency, voltage doesn't matter.
    Example; 994.6 watts id the result for a 75% efficiency rating.
  • Apparent vs True Power
    • Power is less than apparent power for reactive circuits.
  • Power in Resistive Circuit
    • Example: P=I2∗RP = I^2 * R, Total power being used is 2,645 watts.
  • Electrical Power Requirements
    • Most electricity depends on the 1/5 HorsePower/24-volt motor operating at 75%.
  • Electrical Power Unit
    • What measures the electrical power. Watt.
  • Transformer Current
    • Current is stepped down by ratio of 1 to 4 in a voltage step-up transformer and gives 1/4 of the current.
  • Resistor Power Dissipation
    • Power dissipated in a resistor is 35 milliwatts in a 14-ohm resistor in a series circuit carrying 0.05 ampere.
  • Current in Series Circuit
    • Voltage over each resistor goes through each resistor.
    • Example: Current of 0.93 ampere flows through a 3-ohm resistor in a 28-volt circuit with 3, 5, and 22 ohm resistors.
  • Voltage Drop in Series Circuit
    • Voltage drop = (Current * Resistor), used to determine drop in a series-circuit when they voltage and resistor is known.
  • Voltage Across Parallel Lights
    • When lights are connected in parallel across a voltage source, the voltage across each of the lights will be the same as the voltage of the source.
  • Voltage Across Parallel Resistor
    • Is equivalent to the voltage of the source.
    • Example VR3: is 24 V in a parallel circuit with 6-ohm resistors across a 24 volt battery.
  • Corrent Circuit
    • Total resistance will be smaller that the smallest resistor in the parallel, which contains paths of currents to follow for a smooth follow.
  • Cell Seris
    • The result of: (number of cells) multiplied by (Volts) which equal the total Voltage in a circuit.
    • Example: A 12 cells connected to a series equal 2 Volts each, then the lead acid battery will be rated 24 Volts.
  • Lead-Acid internal resistance
    • Ohm's are measured by using 10 amperes to a 2-ohm resistance while the 12 cells are not load which equal 2.1 Volts per cell result 0.52 ohm.
  • Lead-Acid Electrolyte spill
    -The spill should be neutralized with a solution of baking soda (sodium bicarbonate) with water, then the area should be rinsed with water.
  • Hydrometer Reading of a lead-acid
    • The temperature must be observed.
      Example: No correction is necessary if the electrolyte temperature is between 70 and 90F, corrections of 0.4 should be added or substracted from the value if it's below or up 80F.
  • A fully charged lead-acid battery
    • It won't freeze due the fact that most of its acid is in the solution decreasing drastically the freezing point, when the charges joined with Hydrogen Atoms.
  • Amount of current while charging using constant voltage
    • The state-of-charger Battery's level voltage determines the amount while in constant source.
  • Charging aircraft batteries
    Different Voltage must be charged with different Method.
    Series must be in constance current.
  • Rapidly charged battery using Nickel-Cadmium
    • Most be using a constant Volte and vary current.
  • Space underneath the plates in a lead-acid
    • Should be provide due to: Prevents the contact to the plates in case of excessive sediment accumulation.
  • Improper cell torque in Nickel-Cadmium
  • Is indicated due to hardware marking, and burning issues
  • Deposits on the top of Nickel-Cadmium
  • Are indicated on their top part due to normal operations.
  • Servicing and charging Nickel-Cadmium with lead-acid batteries
  • Is very destructive due to the electrochemistry differences between those.
  • Nickel-Cadmium Operating Principal
  • The levels of electrochemistry should be the lowest and the level should reach completely, and use some gassing for a complete charge.
  • Nickel-Cadmium Electrolyte Level
  • It is lowest when the battery is discharged.
  • Fully charged Nickel-Codmium electrolyze
  • Absorbs some in the battery plates and it's charged fully.
    • End-of-charge Voltage measurement of 1.4 can be variable, however is more specific depending on the temperature.
  • During discharging Nickel-Cadmium batteries
    • Electrolyte will be absorbed into the plates.
  • State of charged Nickel-Cadmium
    • By a measuring discharge.
  • Water added with charge
    • Should be avoided due to excessive spewing during circuit.
      -In-Cadmium rise in temperature= Decrease voltage.
  • Thermal Runaway in Nick-Cadmium
    • Runs during High current due to low internal resistance.
  • Gas emitting applied during circuit
    • Oxygen is then removed from the plates.
  • Transformers operations
    • Is in the use of mutual inductance with alternative current.
  • Thermal Switch Design
    -Open the circuit order to allow cooling of thee motor.
  • Rectifier circuit
    Diode.
  • Diode Application
    = Rectifiers.
    In P-N-P transistors:
    Turned ON, negative base with the emitter.
  • N-P-N transistors: Turned On, positive base with the emitter.
  • Zener diode:
    Voltage regulators.
  • Forward biasing: Conduct.
  • Logic gates:
    = Any input creates an Output of (1).OR.
  • Zero Output
    AND: Is equal to Zero when all Inputs are zero.
  • Exclusive or gates:
    There will be 1 on the output when one and only one input has a 1 on it.
  • Electrostatic Fields:
    Dielectric
  • Wire used to Close push to test circuit.
  • Green light
    Will only show in circuit if there is not a 6 broken wire.
  • PCO Rely Fails
    = It will result a a fuel tank light fails too operate but the rest of the machine does still operate. Contact 13 won't complete the light.
  • TCO Relay
    DC must be applied to bus, the Fuel talk set motor must be in crossfeed.
  • Power
    Is switched for tanks, they are three relays one. RTC, PCC, TCC
  • When Power Supplied Fuel Tank: 7 Switches will Change position.. 5,6.11,12,13.15 and 16 change as well.
  • Potentiometer's:
    is identified with 3.
  • Electrical Symbol represented with 5 on graph
    Is indicated as a Capacitor.
    Control switch must be neutral to prevent warming horn operation of the throttles are closed..
  • Ground is not provided :
    Through gears via switches.
  • Voltmeter troubleshooting:
    Will display voltage in a system
  • Variable resistors:
    Symbol 2.
  • If the Break Occurs:
    Can not be turned OFF.
    Will be in full bright if resistance stick-up.