* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Amateur Radio Technician Class Element 2 Course Presentation
Electric power system wikipedia , lookup
Utility frequency wikipedia , lookup
Three-phase electric power wikipedia , lookup
Electrical substation wikipedia , lookup
Ground (electricity) wikipedia , lookup
Power inverter wikipedia , lookup
Mercury-arc valve wikipedia , lookup
Variable-frequency drive wikipedia , lookup
Power engineering wikipedia , lookup
History of electric power transmission wikipedia , lookup
Power MOSFET wikipedia , lookup
Opto-isolator wikipedia , lookup
Spark-gap transmitter wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Surge protector wikipedia , lookup
Voltage optimisation wikipedia , lookup
Current source wikipedia , lookup
Power electronics wikipedia , lookup
Stray voltage wikipedia , lookup
Electrical ballast wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Buck converter wikipedia , lookup
Technician Licensing Class “T4” Presented by the Plano Texas Stake Plano, Texas January 13, 2007 Amateur Radio Technician Class Element 2Course Presentation • ELEMENT 2 SUBELEMENTS • • • • • • • • • • T1 T2 T3 T4 T5 T6 T7 T8 T9 T0 - FCC Rules, station license responsibilities Control operator duties Operating practices Radio and electronic fundamentals Station setup and operation Communications modes and methods Special operations Emergency and Public Service Communications Radio waves, propagation, and antennas Electrical and RF Safety 2 Radio and electronic fundamentals T4A Names of electrical units: DC and AC • Electrical current is measured in the following units: Amperes • The name for the flow of electrons in an electric circuit is: Current • The name for a current that flows only in one direction is: Direct Current (DC) 3 Radio and electronic fundamentals T4A Names of electrical units: DC and AC • Electrical Power is measured in the following units: Watt • The standard unit of frequency is: Hertz • The basic unit of resistance is: Ohm • The name for current that reverses direction on a regular basis is: Alternating Current (AC) 4 Multimeter(s) Multimeters will measure Voltage, Current and Resistance. Be sure it is set properly to read what is being measured. If it is set to the ohms setting and voltage is measured the meter could be damaged! Radio and electronic fundamentals T4A Conductors and insulators (cont) • Copper is a good electrical conductor. • Glass is a good electrical insulator. • The term used to describe opposition to current flow in ordinary conductors such as wires is: Resistance. 6 Radio and electronic fundamentals Conductors and insulators • Conductors Gold Silver Copper Aluminum • Insulators Air Rubber Plastic Ceramic T4A Radio and electronic fundamentals T4A Two types of electricity: • Direct Current - flows in 1 direction Battery 1.5 to 2.5 volts per cell Car battery nominal 12 volts Measured strictly by amplitude • Alternating Current - alternates direction Household Measured by Average Amplitude Frequency (cycles per second)(Hertz) 8 Alternating & Direct Current V+ DC 0V AC Vtime 9 Radio and electronic fundamentals T4A Electrical components • An automobile battery usually supplies about 12 volts [DC]. • An Ammeter is an instrument used to measure the flow of current in an electrical circuit. • A Voltmeter is an instrument used to measure Electromotive Force (EMF) between two points such as the poles of a battery. 10 Radio and electronic fundamentals T4A Ammeter Power Supply Transceiver 11 Radio and electronic fundamentals T4A Ohmmeter 12 Radio and electronic fundamentals T4A Voltmeter Power Supply Transceiver 13 Radio and electronic fundamentals T4B Relationship between frequency and wavelength • Wavelength is the term used for the distance a radio wave travels during one complete cycle. • The term Frequency describes the number of times that an alternating current flows back and forth per second. • Sixty (60) hertz (Hz) means 60 cycles per second. 14 The Relationship of Frequency and Wavelength The distance a radio wave travels in one cycle is called wavelength. V+ One Cycle 0V time V- One Wavelength Radio and electronic fundamentals T4B Relationship between frequency and wavelength • The wavelength gets shorter as the frequency increases. • Wavelength in meters equals 300 divided by frequency in megahertz. • A radio wave travels through space at the speed of light. 16 Radio and electronic fundamentals T4B Identification of bands • The property of a radio wave often used to identify the different bands amateur radio operators use is the physical length of the wave. • The frequency range of the 2-meter band in the United States is 144 to 148 MHz. • The frequency range of the 6-meter band in the United States is 50 to 54 MHz. • The frequency range of the 70-centimeter band in the United States is 420 to 450 MHz. 17 Radio and electronic fundamentals T4B Names of frequency ranges, types of waves • Voice frequencies are sound waves in the range between 300 and 3000 Hertz. • Electromagnetic waves that oscillate more than 20,000 times per second as they travel through space are generally referred to as Radio waves. 18 Radio and electronic fundamentals T4C How radio works: receivers, transmitters, transceivers, amplifiers, power supplies, types of batteries, service life A Receiver is used to convert radio signals into sounds we can hear. A Transmitter is used to convert sounds from our voice into radio signals. A Receiver and Transmitter are two devices combined into one unit in a transceiver. 19 Radio and electronic fundamentals T4C How radio works: receivers, transmitters, transceivers, amplifiers, power supplies, types of batteries, service life (cont) A Power Supply is the device used to convert the alternating current from a wall outlet into low-voltage direct current. An Amplifier is a device used to increase the output of a 10 watt radio to 100 watts. 20 Radio and electronic fundamentals How radio works: receivers, transmitters, transceivers, amplifiers, power supplies, types of batteries, service life T4C (cont) A Lithium-ion battery offers the longest life when used with a hand-held radio, when comparing battery types of the same physical size. The nominal voltage per cell of a fully charged nickel-cadmium battery is 1.2 volts. A Carbon-zinc battery is not designed to be re-charged. 21 Radio and electronic fundamentals T4C How radio works: receivers, transmitters, transceivers, amplifiers, power supplies, types of batteries, service life (cont) • In order to keep rechargeable batteries in good condition and ready for emergencies: They must be inspected for physical damage and replaced if necessary They should be stored in a cool and dry location They must be given a maintenance recharge at least every 6 months All of these answers are correct • The best way to get the most amount of energy from a battery is to draw current from the battery at the slowest 22 rate needed. Radio and electronic fundamentals T4D Ohms law relationships • The formula, Voltage (E) equals current (I) multiplied by resistance (R). = I*R E • The formula, Current (I) equals voltage (E) divided by resistance (R). = E/R I • The formula, Resistance (R) equals voltage (E) divided by current (I). R = E/I 23 Meter Excercise What circuit quantity would meter A indicate? + Battery voltage Meter B R Meter A What circuit quantity would meter B indicate? The current flowing through the resistor 24 Ohms Law Electromotive Force, VOLTS E The flow of Electrons, AMPERES I R Resistance to current flow, OHMS 25 Radio and electronic fundamentals T4D Ohms law relationships (cont) • If I=3 amperes and E=90 volts. R = E/I = R = 90/3= 30 • If E=12 volts and I=1.5 amperes. R = E/I = R = 12/1.5= 8 • If E=120 volts and R=80 ohms. I = E/R = I = 120/80= 1.5 26 Radio and electronic fundamentals Ohms law relationships T4D (cont) • If a current of 0.5 amperes flows through a 2 ohm resistor. E=I*R E = 0.5 * 2 = 1 volt • If a current of 1 ampere flows through a 10 ohm resistor. E=I*R E = 1 * 10 = 10 volts • If a current of 2 amperes flows through a 10 ohm resistor. E=I*R E = 2 * 10 = 20 volts • Current through a 100 ohm resistor across 200 volts. I=E/R I = 200/100 = 2 amperes • Current through a 24 ohm resistor across 240 volts. I=E/R I = 240/24 = 10 amperes 27 Radio and electronic fundamentals T4D Ohms law relationships (cont) • If a current of 0.5 amperes flows through a 2 ohm resistor. E=I*R E = 0.5 * 2 = 1 volt • If a current of 1 ampere flows through a 10 ohm resistor. E=I*R E = 1 * 10 = 10 volts • If a current of 2 amperes flows through a 10 ohm resistor. E=I*R E = 2 * 10 = 20 volts • Current through a 100 ohm resistor across 200 volts. I=E/R I = 200/100 = 2 amperes • Current through a 24 ohm resistor across 240 volts. I=E/R I = 240/24 = 10 amperes 28 Power Power is measured in Watts + Meter B R P=ExI Ohms law states E= I x R Meter A Substituting I x R for E in the power equation gives: P = I x R x I = R x 2 x I = R x I2 So, for this circuit, the power consumed in the resistor can be calculated by multiplying the value of the resistor times the square of the reading of Meter B. 29 Radio and electronic fundamentals T4E Power calculations • The unit used to describe electrical power is the Watt. • The formula: Power (P) equals voltage (E) multiplied by current (I). P=I*E 30 Radio and electronic fundamentals • Power calculations T4E (cont) • How much power is represented by a voltage of 13.8 volts DC and a current of 10 amperes. P = I * E P = 10 * 13.8 = 138 watts • How much power is being used in a circuit when the voltage is 120 volts DC and the current is 2.5 amperes. P = I * E P = 2.5 * 120 = 300 watts 31 Radio and electronic fundamentals T4E Power calculations (cont) • You can you determine how many watts are being drawn [consumed] by your transceiver when you are transmitting by measuring the DC voltage at the transceiver and multiplying by the current drawn when you transmit. • How many amperes is flowing in a circuit when the applied voltage is 120 volts DC and the load is 1200 watts. • I = P/E I = 1200/120 = 10 amperes. 32 Ohm’s law formulas 33 Metric Prefixes Metric Exponent English Tera Giga Mega 1012 109 106 Trillion Billion Million Kilo Centi Milli Micro Nano Pico 103 10-2 10-3 10-6 10-9 10-12 Thousand Hundredth Thousandth Millionth Billionth Trillionth 34 Radio and electronic fundamentals T4 Units, kilo, mega, milli, micro • One thousand volts is equal to one kilovolt. • Another way to specify the frequency of a radio signal that is oscillating at 1,500,000 Hertz is 1500 kHz [or 1.5 megahertz] • 1500 milliamperes is the same as 1.5 amperes. • A hand-held transceiver that has an output power of 500 milliwatts can otherwise be said to output 0.5 watts. • One one-millionth of a volt is equal to one microvolt. 35 Take aways • • • • • • Unit of current… amperes Electron flow is current Current flowing in one direction is DC Unit of power … Watt Unit of frequency … Hertz Unit of resistance … Ohm • Current that reverses direction is AC 36 Take aways (cont) • Copper is a good conductor • Glass is a good insulator • Opposition to current flow …. Resistance • Conductors…gold, silver, copper, aluminum • Insulators…air, rubber, plastic, ceramic 37 Take aways (cont) • Car battery … 12 volts DC • DC measured by amplitude • AC measured by Average Amplitude • Ammeter measures current • Volt meter measures voltage • Sixty hertz means 60 cycles per second 38 Take aways (cont) • Frequency describes number of times AC flows back and forth per second • Wavelength is distance a radio wave travels during one complete cycle • Frequency increases as wavelength gets shorter • Wavelength in meters equals 300 divided by frequency in MHz • Radio waves travel at speed of light 39 Take aways (cont) • Bands identified by physical length (or wavelength) • 2-meter band 144 to 148 MHz • 6-meter band 50 to 54 MHz • 70-centimeter band 420 to 450 MHz • Sound waves 300 to 3000 Hertz • Radio waves are Electromagnetic and are 20,000 cycles per second and higher 40 Take aways (cont) • Receiver converts radio signals to audio • Transmitter converts sound into radio waves • Transceiver is two devices in one, receiver and transmitter • Power supply converts AC to DC. • Amplifier increases power output • Lithium-ion battery offers longest life in HT’s • Ni-Cad per cell voltage is 1.2 volts • Carbon-zinc battery cannot be re-charged 41 Take aways (cont) • Keep re-chargeable batteries in good condition for emergencies Inspect for damage Store in cool and dry location Given maintenance recharge every 6 months All of these answers are correct • Slowest rate of current drain gives most amount of energy 42 Take aways (cont) Ohms Law Power calculations 43 Take aways (cont) • One kilovolt is one thousand volts • 1500 KHz is 1,500,000 Hertz • 1.5 amps is 1500 milliamperes • 500 milliwatts is 0.5 watts • One microvolt is one one-millionth of a volt 44 Element 2 Technician Class Question Pool T4 Valid July 1, 2006 Through June 30, 2010 45 T4A01 Electrical current is measured in which of the following units? A. B. C. D. Volts Watts Ohms Amperes 46 T4A02 Electrical Power is measured in which of the following units? A. B. C. D. Volts Watts Ohms Amperes 47 T4A03 What is the name for the flow of electrons in an electric circuit? A. B. C. D. Voltage Resistance Capacitance Current 48 T4A04 What is the name of a current that flows only in one direction? A. B. C. D. An alternating current A direct current A normal current A smooth current 49 T4A05 A. B. C. D. What is the standard unit of frequency? The megacycle The Hertz One thousand cycles per second The electromagnetic force 50 T4A06 How much voltage does an automobile battery usually supply? A. B. C. D. About 12 volts About 30 volts About 120 volts About 240 volts 51 T4A07 What is the basic unit of resistance? A. B. C. D. The volt The watt The ampere The ohm 52 T4A08 What is the name of a current that reverses direction on a regular basis? A. B. C. D. An alternating current A direct current A circular current A vertical current 53 T4A09 Which of the following is a good electrical conductor? A. B. C. D. Glass Wood Copper Rubber 54 T4A10 Which of the following is a good electrical insulator? A. B. C. D. Copper Glass Aluminum Mercury 55 T4A11 A. B. C. D. What is the term used to describe opposition to current flow in ordinary conductors such as wires? Inductance Resistance Counter EMF Magnetism 56 T4A12 What instrument is used to measure the flow of current in an electrical circuit? A. B. C. D. Frequency meter SWR meter Ammeter Voltmeter 57 T4A13 What instrument is used to measure Electromotive Force (EMF) between two points such as the poles of a battery? A. B. C. D. Magnetometer Voltmeter Ammeter Ohmmeter 58 T4B01 What is the name for the distance a radio wave travels during one complete cycle? A. B. C. D. Wave speed Waveform Wavelength Wave spread 59 T4B02 What term describes the number of times that an alternating current flows back and forth per second? A. B. C. D. Pulse rate Speed Wavelength Frequency 60 T4B03 What does 60 hertz (Hz) mean? A. B. C. D. 6000 cycles per second 60 cycles per second 6000 meters per second 60 meters per second 61 T4B04 Electromagnetic waves that oscillate more than 20,000 times per second as they travel through space are generally referred to as what? A. B. C. D. Gravity waves Sound waves Radio waves Gamma radiation 62 T4B05 How fast does a radio wave travel through space? A. At the speed of light B. At the speed of sound C. Its speed is inversely proportional to its wavelength D. Its speed increases as the frequency increases 63 T4B06 How does the wavelength of a radio wave relate to its frequency? A. The wavelength gets longer as the frequency increases B. The wavelength gets shorter as the frequency increases C. There is no relationship between wavelength and frequency D. The wavelength depends on the bandwidth of the signal 64 T4B07 What is the formula for converting frequency to wavelength in meters? A. Wavelength in meters equals frequency in Hertz multiplied by 300 B. Wavelength in meters equals frequency in Hertz divided by 300 C. Wavelength in meters equals frequency in megahertz divided by 300 D. Wavelength in meters equals 300 divided by frequency in megahertz 65 T4B08 A. B. C. D. What are sound waves in the range between 300 and 3000 Hertz called? Test signals Ultrasonic waves Voice frequencies Radio frequencies 66 T4B09 What property of a radio wave is often used to identify the different bands amateur radio operators use? A. The physical length of the wave B. The magnetic intensity of the wave C. The time it takes for the wave to travel one mile D. The voltage standing wave ratio of the wave 67 T4B10 What is the frequency range of the 2 meter band in the United States? A. B. C. D. 144 to 148 MHz 222 to 225 MHz 420 to 450 MHz 50 to 54 MHz 68 T4B11 What is the frequency range of the 6 meter band in the United States? A. B. C. D. 144 to 148 MHz 222 to 225 MHz 420 to 450 MHz 50 to 54 MHz 69 T4B12 What is the frequency range of the 70 centimeter band in the United States? A. B. C. D. 144 to 148 MHz 222 to 225 MHz 420 to 450 MHz 50 to 54 MHz 70 T4C01 What is used to convert radio signals into sounds we can hear? A. B. C. D. Transmitter Receiver Microphone Antenna 71 T4C02 What is used to convert sounds from our voice into radio signals? A. B. C. D. Transmitter Receiver Speaker Antenna 72 T4C03 What two devices are combined into one unit in a transceiver? A. B. C. D. Receiver, transmitter Receiver, transformer Receiver, transistor Transmitter, deceiver 73 T4C04 What device is used to convert the alternating current from a wall outlet into low-voltage direct current? A. B. C. D. Inverter Compressor Power Supply Demodulator 74 T4C05 What device is used to increase the output of a 10 watt radio to 100 watts? A. B. C. D. Amplifier Power supply Antenna Attenuator 75 T4C06 Which of the battery types listed below offers the longest life when used with a hand-held radio, assuming each battery is the same physical size? A. B. C. D. Lead-acid Alkaline Nickel-cadmium Lithium-ion 76 T4C07 What is the nominal voltage per cell of a fully charged nickel-cadmium battery? A. B. C. D. 1.0 volts 1.2 volts 1.5 volts 2.2 volts 77 T4C08 What battery type on this list is not designed to be re-charged? A. B. C. D. Nickel-cadmium Carbon-zinc Lead-acid Lithium-ion 78 T4C09 What is required to keep rechargeable batteries in good condition and ready for emergencies? A. They must be inspected for physical damage and replaced if necessary B. They should be stored in a cool and dry location C. They must be given a maintenance recharge at least every 6 months D. All of these answers are correct 79 T4C10 What is the best way to get the most amount of energy from a battery? A. Draw current from the battery as rapidly as possible B. Draw current from the battery at the slowest rate needed C. Reverse the leads when the battery reaches the 1/2 charge level D. Charge the battery as frequently as possible 80 T4D01 What formula is used to calculate current in a circuit? A. Current (I) equals voltage (E) multiplied by resistance (R) B. Current (I) equals voltage (E) divided by resistance (R) C. Current (I) equals voltage (E) added to resistance (R) D. Current (I) equals voltage (E) minus resistance (R) 81 T4D02 What formula is used to calculate voltage in a circuit? A. Voltage (E) equals current (I) multiplied by resistance (R) B. Voltage (E) equals current (I) divided by resistance (R) C. Voltage (E) equals current (I) added to resistance (R) D. Voltage (E) equals current (I) minus resistance (R) 82 T4D03 What formula is used to calculate resistance in a circuit? A. Resistance (R) equals voltage (E) multiplied by current (I) B. Resistance (R) equals voltage (E) divided by current (I) C. Resistance (R) equals voltage (E) added to current (I) D. Resistance (R) equals voltage (E) minus current (I) 83 T4D04 What is the resistance of a circuit when a current of 3 amperes flows through a resistor connected to 90 volts? A. B. C. D. 3 ohms 30 ohms 93 ohms 270 ohms 84 T4D05 What is the resistance in a circuit where the applied voltage is 12 volts and the current flow is 1.5 amperes? A. B. C. D. 18 ohms 0.125 ohms 8 ohms 13.5 ohms 85 T4D06 What is the current flow in a circuit with an applied voltage of 120 volts and a resistance of 80 ohms? A. B. C. D. 9600 amperes 200 amperes 0.667 amperes 1.5 amperes 86 T4D07 What is the voltage across the resistor if a current of 0.5 amperes flows through a 2 ohm resistor? A. B. C. D. 1 volt 0.25 volts 2.5 volts 1.5 volts 87 T4D08 What is the voltage across the resistor if a current of 1 ampere flows through a 10 ohm resistor? A. B. C. D. 10 volts 1 volt 11 volts 9 volts 88 T4D09 What is the voltage across the resistor if a current of 2 amperes flows through a 10 ohm resistor? A. B. C. D. 20 volts 0.2 volts 12 volts 8 volts 89 T4D10 What is the current flowing through a 100 ohm resistor connected across 200 volts? A. B. C. D. 20,000 amperes 0.5 amperes 2 amperes 100 amperes 90 T4D11 What is the current flowing through a 24 ohm resistor connected across 240 volts? A. B. C. D. 24,000 amperes 0.1 amperes 10 amperes 216 amperes 91 T4E01 What unit is used to describe electrical power? A. B. C. D. Ohm Farad Volt Watt 92 T4E02 What is the formula used to calculate electrical power? A. Power (P) equals voltage (E) multiplied by current (I) B. Power (P) equals voltage (E) divided by current (I) C. Power (P) equals voltage (E) minus current (I) D. Power (P) equals voltage (E) plus current (I) 93 T4E03 How much power is represented by a voltage of 13.8 volts and a current of 10 amperes? A. B. C. D. 138 watts 0.7 watts 23.8 watts 3.8 watts 94 T4E04 How much power is being used in a circuit when the voltage is 120 volts and the current is 2.5 amperes? A. B. C. D. 1440 watts 300 watts 48 watts 30 watts 95 T4E05 How can you determine how many watts are being drawn by your transceiver when you are transmitting? A. Measure the DC voltage and divide it by 60 Hz B. Check the fuse in the power leads to see what size it is C. Look in the Radio Amateur's Handbook D. Measure the DC voltage at the transceiver and multiply by the current drawn when you transmit 96 T4E06 How many amperes are flowing in a circuit when the applied voltage is 120V and the load is 1200 watts? A. B. C. D. 20 amperes 10 amperes 120 amperes 5 amperes 97 T4E07 How many milliamperes is the same as 1.5 amperes? A. B. C. D. 15 milliamperes 150 milliamperes 1500 milliamperes 15000 milliamperes 98 T4E08 What is another way to specify the frequency of a radio signal that is oscillating at 1,500,000 Hertz? A. B. C. D. 1500 kHz 1500 MHz 15 GHz 150 kHz 99 T4E09 A. B. C. D. How many volts are equal to one kilovolt? one one-thousandth of a volt one hundred volts one thousand volts one million volts 100 T4E10 How many volts are equal to one microvolt? A. B. C. D. one one-millionth of a volt one million volts one thousand kilovolts one one-thousandth of a volt 101 T4E11 How many watts does a hand-held transceiver put out if the output power is 500 milliwatts? A. B. C. D. 0.02 watts 0.5 watts 5 watts 50 watts 102