AE/AT Elementary Electrical Engineering - Module 4 - ELECTRICAL MATERIALS
Electrical materials are used in electrical construction projects for specific purposes.
Electrical materials include electronic devices, cables, and fixtures.
They control the flow of current and carry electrical current from the source to the load.
Electrical materials can be classified based on their electrical conductivity.
Conductors allow the flow of electric charges, such as silver and gold.
Insulators impede the flow of electrons and tightly bind their particles.
Semiconductors exhibit intermediate conductivity and have more charge carriers than insulators but fewer than conductors.
Superconductors become perfect conductors at a critical temperature, with zero power loss.
Semiconductors can be used to fabricate resistors, capacitors, inductors, and transistors.
Integrated circuits (ICs) combine millions or billions of transistors into a small package.
Superconductors exhibit zero power loss at a critical temperature.
Electrical components are classified into active components and passive components.
Active components supply and control energy, while passive components respond to the flow of electrical energy.
Passive components include resistors, capacitors, and inductors.
Transistors are electronic devices made of semiconductor material that control the flow of voltage or current.
Switches are electrical devices used to break the circuit and interrupt the current flow.
Diodes allow current to flow in one direction and block current going against the flow.
Fuses protect components from destruction due to excessive current flow.
Transformer:
A passive electrical device consisting of cores and soft wire linked by an iron core.
Transfers electrical energy between two or more circuits.
Battery:
An electrical device used to convert chemical energy into electrical energy.
Operates through electrochemical discharge reactions.
Tandanum battery converts chemical energy into electrical energy.
Generators convert mechanical energy into electrical energy through electromagnetic induction
AC generators convert mechanical energy into electrical energy in the form of alternating current
Dynamo is an electrical generator that creates direct current using a commutator
Electrical measuring instruments are used to measure various electrical quantities
Common types of measuring instruments include ammeters, voltmeters, ohmmeters, and wattmeters
Ammeters measure electric current, voltmeters measure voltage, ohmmeters measure resistance, and wattmeters measure power
Absolute instruments give the value of the measured quantity in terms of the physical constants of the instrument
Secondary instruments are calibrated and directly give the value of the measured quantity
Indicating instruments have a pointer that moves over a calibrated scale to indicate the measured quantity
Recording instruments record the measured quantity on graph paper for a desired period
Integrating instruments measure the total quantity of electricity consumed in a circuit over a given time
Magnetic effects, electrodynamic effects, and electromagnetic induction effects are used in ammeters, voltmeters, and wattmeters
Electrostatic effects are used in voltmeters
Chemical effects are used in DC ammeters
Heating effects are used in ammeters and voltmeters
Ammeters measure electric current and can be calibrated in amperes, milliamperes, or microamperes
Ammeters are inserted in series with the circuit being tested, increasing the resistance of the circuit by the internal resistance of the meter
The accuracy of an ammeter is the ratio of the current with the meter to the current without the meter
The percent loading error is the percent error in the ammeter reading due to the added resistance of the meter
Shunted ammeters use a shunt resistor to extend the range of the ammeter for measuring higher currents
The current through the ammeter is equal to the current through the shunt plus the full-scale deflection current of the ammeter
The shunt resistor value can be calculated using Ohm's law and Kirchhoff's current law
The input resistance of the shunted ammeter is calculated using the current through the shunt and the full-scale deflection current of the ammeter
Voltmeters measure potential difference or voltage in a circuit
A simple DC voltmeter can be constructed by placing a resistor called the multiplier in series with the ammeter movement
The sensitivity factor of a voltmeter is the reciprocal of the full-scale current
The input resistance of a voltmeter is calculated using the full-scale voltage and the full-scale current
When a voltmeter is connected to a circuit, it draws current and produces a voltage drop across its coil resistance
The loading effect is the ratio of the voltage with the voltmeter to the voltage without the voltmeter
The unloading error is the percent error in the voltmeter reading due to the loading effect
Constructing a multi-range voltmeter
Using a 50 microampere meter movement with internal resistance of 2 kilo ohms
Ranges: 5, 10, and 25 volts
Finding the multiplier resistance, R sub s, for each range
Values for each range: 1.98, 1.98, and 4.98 kilo ohms
Ohmmeter components: battery, meter movement calibrated to ohms, R sub O (current limiting resistance), R sub A (adjustable resistor for zeroing and correcting battery aging), R sub X (known resistance to be measured)
Zeroing the ohmmeter by short-circuiting terminals A and B and adjusting R sub O for full-scale deflection
Formula for calculating R sub X: R sub X = 1 - D/D * R sub O
Half-scale deflection occurs when D = 1/2, R sub X = R sub O
Meter movement with full-scale deflection of 50 microamperes
Open circuit voltage at terminals A and B is 6 volts
Ohmmeter zeroed, unknown resistor R sub X measured, produces quarter-scale deflection
Calculating R sub O: R sub O = V/I sub M = 6 volts / 50 microamperes = 120 kilo ohms
Calculating R sub X: R sub X = 1 - D/D * R sub O = 1 - 1/4 / 1/4 * 120 = 360 kilo ohms
Multimeter measures voltage, resistance, and current
VOM (volt-ohm milliammeter) is the most common multimeter
VOM has a meter movement with full-scale current of 50 microamperes
One meter movement used to measure milliamperes, DC voltage, AC voltage, and ohms
VOM voltage range extends from 2.5 volts to 5000 volts
Sensitivity of 20 kilo ohms per volt
Input resistance for lowest range (2.5 volts): 50 kilo ohms
Input resistance for highest range (5000 volts): 100 mega ohms
AC meters measure current and voltage that change periodically with time
Two methods for measuring AC current or voltage: electron mechanical meter movements for low frequencies, d arson valve movement for high frequencies
Simplest type of AC voltmeter
Diode allows current flow in one direction during positive half cycle, high resistance during negative half cycle
Resulting current through meter is RMS calibrated reading
AC ammeters indicate average value
Formula for converting average value to RMS: I sub B = I sub A B / 0.3185
AC meters marked off to indicate effective or RMS value: I sub RMS = 0.707 I sub B
Formula for calculating RMS voltage: V sub RMS = 0.707 I sub B (R sub S + R sub M)
Formula for calculating input resistance: R sub I N = 0.45 V sub M / I sub M
R sub S = 1 mega ohm
Meter movement full-scale current = 50 microamperes
Calculating RMS value of input sine wave for full-scale deflection
Formula: V sub RMS = 2.22 I sub M R sub I N
Calculating V sub RMS: 0.22 * 50 * 1,000,000 = 11,000,000 volts
Improving sensitivity of rectifier type AC meter by using full wave rectification
Full wave bridge detector with 100 microampere meter movement and 1 kilo ohm resistance
Calculating size of R sub S for 50 volt RMS sine wave to produce full-scale deflection: R sub S = 450 kilo ohms
Measures DC power or real AC power
Fixed coils indicate current, movable coil indicates voltage
Power dissipated in DC circuit: P = V * I
Power dissipated in AC circuit: P = V sub RMS * I sub RMS * cos Theta
Voltage and current supplied to a load: peak values of 162 volts and 5 amperes, phase angle of 30 degrees
Calculating reading of the wattmeter using power formula: P = V sub RMS * I sub RMS * cos Theta
Vrms is equal to 0.707 V sub b or peak voltage
Convert into RMS for module number four
Vrms multiplied by Irms multiplied by cos Theta is equal to 144.534 volts times 3.535 amperes cosine 30
B is equal to 350.63 watts
Why is it important to work safely with or near electricity?
What should you do if you find equipment defective?
Mentioned synchronous classes and midterm exam
Told classmates about the exam
Five points on when and how to inspect powered hand tools and other electrical equipment
Module number four
Congratulations on completing module number four
Questions or concerns can be addressed through email, messenger, or Discord
Electrical materials are used in electrical construction projects for specific purposes.
Electrical materials include electronic devices, cables, and fixtures.
They control the flow of current and carry electrical current from the source to the load.
Electrical materials can be classified based on their electrical conductivity.
Conductors allow the flow of electric charges, such as silver and gold.
Insulators impede the flow of electrons and tightly bind their particles.
Semiconductors exhibit intermediate conductivity and have more charge carriers than insulators but fewer than conductors.
Superconductors become perfect conductors at a critical temperature, with zero power loss.
Semiconductors can be used to fabricate resistors, capacitors, inductors, and transistors.
Integrated circuits (ICs) combine millions or billions of transistors into a small package.
Superconductors exhibit zero power loss at a critical temperature.
Electrical components are classified into active components and passive components.
Active components supply and control energy, while passive components respond to the flow of electrical energy.
Passive components include resistors, capacitors, and inductors.
Transistors are electronic devices made of semiconductor material that control the flow of voltage or current.
Switches are electrical devices used to break the circuit and interrupt the current flow.
Diodes allow current to flow in one direction and block current going against the flow.
Fuses protect components from destruction due to excessive current flow.
Transformer:
A passive electrical device consisting of cores and soft wire linked by an iron core.
Transfers electrical energy between two or more circuits.
Battery:
An electrical device used to convert chemical energy into electrical energy.
Operates through electrochemical discharge reactions.
Tandanum battery converts chemical energy into electrical energy.
Generators convert mechanical energy into electrical energy through electromagnetic induction
AC generators convert mechanical energy into electrical energy in the form of alternating current
Dynamo is an electrical generator that creates direct current using a commutator
Electrical measuring instruments are used to measure various electrical quantities
Common types of measuring instruments include ammeters, voltmeters, ohmmeters, and wattmeters
Ammeters measure electric current, voltmeters measure voltage, ohmmeters measure resistance, and wattmeters measure power
Absolute instruments give the value of the measured quantity in terms of the physical constants of the instrument
Secondary instruments are calibrated and directly give the value of the measured quantity
Indicating instruments have a pointer that moves over a calibrated scale to indicate the measured quantity
Recording instruments record the measured quantity on graph paper for a desired period
Integrating instruments measure the total quantity of electricity consumed in a circuit over a given time
Magnetic effects, electrodynamic effects, and electromagnetic induction effects are used in ammeters, voltmeters, and wattmeters
Electrostatic effects are used in voltmeters
Chemical effects are used in DC ammeters
Heating effects are used in ammeters and voltmeters
Ammeters measure electric current and can be calibrated in amperes, milliamperes, or microamperes
Ammeters are inserted in series with the circuit being tested, increasing the resistance of the circuit by the internal resistance of the meter
The accuracy of an ammeter is the ratio of the current with the meter to the current without the meter
The percent loading error is the percent error in the ammeter reading due to the added resistance of the meter
Shunted ammeters use a shunt resistor to extend the range of the ammeter for measuring higher currents
The current through the ammeter is equal to the current through the shunt plus the full-scale deflection current of the ammeter
The shunt resistor value can be calculated using Ohm's law and Kirchhoff's current law
The input resistance of the shunted ammeter is calculated using the current through the shunt and the full-scale deflection current of the ammeter
Voltmeters measure potential difference or voltage in a circuit
A simple DC voltmeter can be constructed by placing a resistor called the multiplier in series with the ammeter movement
The sensitivity factor of a voltmeter is the reciprocal of the full-scale current
The input resistance of a voltmeter is calculated using the full-scale voltage and the full-scale current
When a voltmeter is connected to a circuit, it draws current and produces a voltage drop across its coil resistance
The loading effect is the ratio of the voltage with the voltmeter to the voltage without the voltmeter
The unloading error is the percent error in the voltmeter reading due to the loading effect
Constructing a multi-range voltmeter
Using a 50 microampere meter movement with internal resistance of 2 kilo ohms
Ranges: 5, 10, and 25 volts
Finding the multiplier resistance, R sub s, for each range
Values for each range: 1.98, 1.98, and 4.98 kilo ohms
Ohmmeter components: battery, meter movement calibrated to ohms, R sub O (current limiting resistance), R sub A (adjustable resistor for zeroing and correcting battery aging), R sub X (known resistance to be measured)
Zeroing the ohmmeter by short-circuiting terminals A and B and adjusting R sub O for full-scale deflection
Formula for calculating R sub X: R sub X = 1 - D/D * R sub O
Half-scale deflection occurs when D = 1/2, R sub X = R sub O
Meter movement with full-scale deflection of 50 microamperes
Open circuit voltage at terminals A and B is 6 volts
Ohmmeter zeroed, unknown resistor R sub X measured, produces quarter-scale deflection
Calculating R sub O: R sub O = V/I sub M = 6 volts / 50 microamperes = 120 kilo ohms
Calculating R sub X: R sub X = 1 - D/D * R sub O = 1 - 1/4 / 1/4 * 120 = 360 kilo ohms
Multimeter measures voltage, resistance, and current
VOM (volt-ohm milliammeter) is the most common multimeter
VOM has a meter movement with full-scale current of 50 microamperes
One meter movement used to measure milliamperes, DC voltage, AC voltage, and ohms
VOM voltage range extends from 2.5 volts to 5000 volts
Sensitivity of 20 kilo ohms per volt
Input resistance for lowest range (2.5 volts): 50 kilo ohms
Input resistance for highest range (5000 volts): 100 mega ohms
AC meters measure current and voltage that change periodically with time
Two methods for measuring AC current or voltage: electron mechanical meter movements for low frequencies, d arson valve movement for high frequencies
Simplest type of AC voltmeter
Diode allows current flow in one direction during positive half cycle, high resistance during negative half cycle
Resulting current through meter is RMS calibrated reading
AC ammeters indicate average value
Formula for converting average value to RMS: I sub B = I sub A B / 0.3185
AC meters marked off to indicate effective or RMS value: I sub RMS = 0.707 I sub B
Formula for calculating RMS voltage: V sub RMS = 0.707 I sub B (R sub S + R sub M)
Formula for calculating input resistance: R sub I N = 0.45 V sub M / I sub M
R sub S = 1 mega ohm
Meter movement full-scale current = 50 microamperes
Calculating RMS value of input sine wave for full-scale deflection
Formula: V sub RMS = 2.22 I sub M R sub I N
Calculating V sub RMS: 0.22 * 50 * 1,000,000 = 11,000,000 volts
Improving sensitivity of rectifier type AC meter by using full wave rectification
Full wave bridge detector with 100 microampere meter movement and 1 kilo ohm resistance
Calculating size of R sub S for 50 volt RMS sine wave to produce full-scale deflection: R sub S = 450 kilo ohms
Measures DC power or real AC power
Fixed coils indicate current, movable coil indicates voltage
Power dissipated in DC circuit: P = V * I
Power dissipated in AC circuit: P = V sub RMS * I sub RMS * cos Theta
Voltage and current supplied to a load: peak values of 162 volts and 5 amperes, phase angle of 30 degrees
Calculating reading of the wattmeter using power formula: P = V sub RMS * I sub RMS * cos Theta
Vrms is equal to 0.707 V sub b or peak voltage
Convert into RMS for module number four
Vrms multiplied by Irms multiplied by cos Theta is equal to 144.534 volts times 3.535 amperes cosine 30
B is equal to 350.63 watts
Why is it important to work safely with or near electricity?
What should you do if you find equipment defective?
Mentioned synchronous classes and midterm exam
Told classmates about the exam
Five points on when and how to inspect powered hand tools and other electrical equipment
Module number four
Congratulations on completing module number four
Questions or concerns can be addressed through email, messenger, or Discord
