Element-3-GSP-AUG182012 reviewer for NTC Exam.pptx

Reviewer for NTC exam

1. Element 3 Fundamentals of Electricity and Electronics GENARO “GENE” A. CUARESMA DU1RNA Makiling Amateur Radio Society (MARS/DX1MK) Philippine Amateur Radio Association (PARA)

2. MATTER Anything that is made up of molecules and atoms. Molecules is made up of atoms. The atom consists of a central nucleus surrounded by negatively charged electrons.

3. ATOM An atom is the smallest particle that comprises a chemical element and at its natural state has zero charge.

4. Basic Electricity Electricity is the flow of electrons from one place to another. An electron is a negatively-charged subatomic particle.

5. Matter can be classified into: Conductors - electrons flow easily, low resistance Semi-conductors - electron can be made to flow under certain circumstances, variable resistance according to formulation and circuit conditions Insulators - electrons flow with great difficulty, high resistance. Matters and its electrical properties

6. Examples rubber – a good insulator of electricity copper – a good conductor of electricity

7. Electrical Units Coulomb (C)- A unit of electrical charge; the quantity of electricity passing in one second through a circuit in which the rate of flow is one ampere  Voltage (symbol E or V, unit volt )- the practical unit of electric pressure;  the pressure which will produce a current of one ampere against a resistance of one ohm Current (symbol I , unit ampere )- the movement of electrons through a conductor

8. Electrical Units Resistance (symbol R, unit Ω or Ohms )- the opposition to the flow of current Capacitance (symbol C , unit Farad )- the ability of a material to store electric charge   Inductance (symbol L , unit Henry )- the ability of conductor to produce induced voltage Frequency (symbol f , unit Hertz )- is a measure of the number of occurrences of repeating event per unit time or cycles per second

9. Test Instruments: Voltmeter - measures voltage Battery Connect the voltmeter in PARALLEL to measure voltage

10. Test Instruments : Ammeter - measures current Battery Connect an Ammeter in SERIES to measure the current in a circuit

11. Ohmmeter - measures resistance Test Instruments:

12. Test Instruments: Multimeter

13. Current Flow Direct Current (DC) - A flow of charged particles through a conductor in one direction only. Alternating Current (AC) - A flow of charged particles through a conductor, first in one direction, then in the other direction

14. Current Flow Direct current:

15. Current Flow Alternating current :

16. In DC circuits, load is measured in resistance only, while in AC and radio circuits we can expect a reactive component in the load and the combination of these two is called impedance .

17. An ideal voltage source should have zero internal resistance . The best device for storing energy in a magnetic field is a coil .

18. ELECTRONICS Electronics is the study of the flow of electrons through materials and devices. An electronic component is any physical entity in an electronic system which affects the electrons. Current flows from + v e to - v e .

19. Basic Electronics Components Resistors a  passive   two-terminal   electrical component  that implements  electrical resistance  as a circuit element. is designed to drop the voltage of the current as it flows from one terminal to the next. A resistor is primarily used to create and maintain a known safe current within an electrical component.

20. Basic Electronics Components Resistors Symbol: Unit : Ohms ( )

21. Some Types of resistors : wire-wound carbon film carbon composition Tantalum is not a type of resistor. Tantalum Capacitor

22. Basic Electronics Components Capacitor a passive electronic component that stores energy in the form of an electrostatic field. In its simplest form, a capacitor consists of two conducting plates separated by an insulating material called the dielectric . The capacitance is directly proportional to the surface areas of the plates, and is inversely proportional to the separation between the plates.

23. Basic Electronics Components Symbol: Unit: Farad (F)

24. Basic Electronics Components Inductor a passive electronic component that stores energy in the form of a magnetic field. In its simplest form, an inductor consists of a wire loop or coil. The inductance is directly proportional to the number of turns in the coil. Inductance also depends on the radius of the coil and on the type of material around which the coil is wound.

25. Basic Electronics Components Inductor Symbol: Unit : Henry (H)

26. Basic Electronic Components RESISTOR INDUCTOR CAPACITOR Symbols

27. Tera T 10 12 Giga G 10 9 Mega M 10 6 Kilo k 10 3 Milli m 10 -3 Micro  10 -6 Nano  10 -9 Pico p 10 -12 Femto f 10 -15 ( in RED are commonly used multiples) 1,000,000,000,000 1,000,000,000 1,000,000 1,000 0.001 0.000 001 0.000 000 001 0.000 000 000 001 0.000 000 000 000 001 Units of Measurement

28. Examples How is 325 kilo-ohms also written? Answer: 325 k Ω How is 888 milliwatt also written? Answer: 888mW How many milliwatts are in 1 watt? Answer: 1000mW What is another way of writing 470 kilo-ohms? Answer: 470,000 ohms

29. Examples What is another way of writing 3000 MHz in GigaHz? Answer: 3 GHz

30. Resistor Color Code Better Be Right Or Your Great Big Venture Goes Wild

31. Resistor Color Code Example What is the value of the resistor having the color bands as follows: violet – violet – blue - no color ? Answer: 77 mega-ohms (  20%)

32. Resistor Color Code Example What is the value of the resistor having the color bands as follows: yellow – violet – orange – no color ? Answer: 47 K  (  20%)

33. Resistor Color Code Example What is the value of the resistor having the color bands as follows: green – black – black - silver ? Answer: 50 ohms ( 10%)

34. Resistor Color Code Example What is the value of the resistor having the color bands as follows: white – white – black - gold ? Answer: 99 ohms (  5%)

35. Ohm's Law the current passing through a conductor between two points is directly proportional to the potential difference (i.e. voltage drop or voltage) across the two points, and inversely proportional to the resistance between them. E

36. Ohm's Law Ohm's magic triangle The magic V I R -triangle can be used to calculate all formulations of Ohm's Law. Use a finger to hide the value to be calculated. The symbol I comes from "International Ampere" and R from "Resistance", and Volts = V or E , the potential difference, also called voltage drop.

37. Ohm's Law Formula E = I x R (Volts) R = E / I (Ohms) I = E / R (Amperes) E

38. Ohm's Law Example: What is the voltage in a simple circuit, if the current is 1 Ampere and the resistance of 30 Ohms? Answer: E = I x R E = 1 x 30 E = 30 Volts

39. Ohm's Law Example: What is the current along a simple circuit, if a 240 Ohm resistor is connected to a 12V battery? Answer: I = V / R I = 12V / 240  I = 0.05 Amp

40. Power Electric power is defined as the rate at which electrical energy is transferred by an electric circuit. Unit of Power : W , watts

41. POWER FORMULA: JOULE’S LAW The rate of heat dissipation in a resistive conductor (or power dissipated in a resistor) is proportional to the square of the current through it and to its resistance. P = I 2 R P = I E , since E = I R (by Ohm’s Law) P = E 2 / R , since I = E / R. Note: P T = P 1 + P 2 + … + P N

42. Power Example: What is the total power dissipated by a load resistor supplied by a 48V-source and having a total current of 1A flow through it? Given: E = 48V I = 1A Solution: P= I x E = 48V x 1A = 48 W

43. Power Example: What is the current flowing through a load having a 12V measurement across it if it dissipates 4W of power? Given: E = 12V and P = 4W Solution: P=I x E  I = P / E = 4W /12V = 0.333 A

44. Battery / Polarity positive polarity + (red) negative polarity - ( black ) A battery is a good source of DC power supply.

45. Circuits Series Circuits - component junctions are connected side by side . Total Resistance, R T R T = R 1 + R 2 +…+ R n Total Inductance, L T L T = L 1 + L 2 +…+ L n Total Capacitance, C T 1/C T = 1/C 1 + 1/C 2 +…+1/ C n

46. Circuits Parallel Circuits - component junctions are connected via a common point . Total Resistance, R T 1/R T = 1/R 1 + 1/R 2 +…+1/ R n Total Inductance, L T 1/L T = 1/L 1 + 1/L 2 +…+1/ L n Total Capacitance, C T C T = C 1 + C 2 +…+ C n

47. Circuits Current remains constant in a SERIES circuit. Voltage remains constant in a PARALLEL circuit. A switch is a component used to turn a circuit on or off .

48. Circuits Example: Inductors in SERIES What is the total inductance of 3 inductors connected in series, with the following values: 3mH, 5mH and 22mH? Given: L 1 =3mH, L 2 =5mH and L 3 =22mH Solution: L T = L 1 + L 2 + L 3 = 3mH + 5mH + 22mH = 30mH

49. Circuits Example: Inductors in PARALLEL What is the total inductance of 2 inductors – valued at 20mH each and are connected in parallel? Given: L 1 = L 2 = 20mH 1/L T = 1/L 1 + 1/L 2 L T = (L 1 x L 2 ) / (L 1 + L 2 ) L T = (20mH x 20mH) / (20mH + 20mH) L T =10mH

50. Circuits Series - Parallel Circuits - components connected in combinations of series and parallel connection. To calculate the total resistance, capacitance and inductance, calculate the parallels first then the series.

51. Series – Parallel Circuits In an electrical circuit R1 and R2 are connected in series. They are further connected to R3 in parallel. A 240V source is connected across the combination. If R1 is 100 Ohms, R2 is 300 Ohms and R3 is 100 Ohms, Find: a. Total resistance of the R1, R2 and R3. b. Total current of the circuit. c. Current across R1, R2 and R3. d. Voltage drop across R1, R2 and R3.

52. a. R12 = R1 + R2 = 100  + 300  = 400 . 1/RT = 1/R12 + 1/R3 = 1/400  + 1/100   RT = 400 /5 = 80 . b. I = V / R = 240V / 80   I = 3A c. V R12 = 240V and V R3 = 240V (why?)  I R12 = 240V / 400  = 0.6A  I R1 = 0.6A and I R2 = 0.6A (why?) and I R3 = 240V / 100  = 2.4A d. V R1 = ( 100  )(0.6A) = 60V V R2 = (3 00  )(0.6A) = 180V

53. Series – Parallel Circuits Capacitors C1 and C2 are connected in parallel to each other. They are further connector to capacitor C3 in series. What is the total combined capacitance of C1, C2 and C3 if C1 = 90pF, C2 = 30pF and C3 = 240pF? Ans : 80pF

54. REACTANCE - opposition to current due to storage of energy - the opposition to (AC) alternating current due to capacitance (capacitive reactance) or inductance (inductive reactance) - Capacitor and Inductor can store energy.

55. INDUCTIVE REACTANCE a quantity characterizing the opposition presented to an alternating current by the inductance of a circuit or of part of a circuit. Inductive reactance is measured in ohms. X L = 2  f L Where X L = Inductive Reactance (in ) f = Frequency (in Hz) L = Inductance (in H)

56. INDUCTIVE REACTANCE Example: A coil of inductance 150mH and zero resistance is connected across a 100V, 50Hz supply. Calculate the inductive reactance of the coil and the current flowing through it. Solution: X L = 2  f L = (2)(3.14)(50Hz)(.150H) = 47.1 I = 100V / 47.1 = 2.12 A

57. CAPACITIVE REACTANCE Where X C = Capacitive Reactance ( ) f = Frequency (Hz) C = Capacitance (F) a quantity characterizing the opposition presented to an alternating current by the capacitance of a circuit or of part of a circuit. Capacitive reactance is measured in ohms.

58. CAPACITIVE REACTANCE Example: Find the current flowing in a circuit when a 4  F capacitor is connected across a 880v, 60Hz supply. Solution: X c = 1/(2 fC) = 1/(2*3.14*60Hz*0.000004F) = 663 I = V / X c = 880V / 663 = 1.33A

59. In an electrical circuit, resonance occurs at a particular frequency when the inductive reactance and the capacitive reactance are of equal magnitude, causing electrical energy to oscillate between the magnetic field of the inductor and the electric field of the capacitor. RESONANT CIRCUIT Where f = Frequency in Hertz L = Inductance in Henry C = Capacitance in Farad

60. RESONANT FREQUENCY

61. RESONANT CIRCUIT Example: Find the resonant frequency of the following circuit: Given: L = 100mH = 0.1 H C = 10 F = 0.00001F

62. RESONANT CIRCUIT The bandwidth of a resonant circuit refers to the frequency range over which the circuit response to voltage or current is no more than 3dB below the peak response. The ( ) 3dB points are also called the half power points where the voltage and current have been reduced to 70.7% of the peak voltage or current.

63. Bandwidth

64. BASIC FORMULA: Where:  is wavelength in meters C is speed of light in air, 3 x 10 8 m/sec f is frequency in Hertz, Hz Frequency / Wavelength Calculation

65. Frequency / Wavelength Calculation Example 144 MHz 300,000,000 m/s 144,000,000 Hertz Wavelength = 2.083 meters ~ 2 Meter This is also the reason why 144Mhz is also called 2-meter band Wavelength =

66. BAND FREQUENCY RANGE     AUDIO FREQUENCY 30 Hz - 30 KHz     RADIO FREQUENCY     VERY LOW FREQUENCY 30 KHz - 300 KHz LOW FREQUENCY 300 KHz - 3 MHz HIGH FREQUENCY 3 MHz - 30 MHz VERY HIGH FREQUENCY 30 MHz - 300 MHz ULTRA HIGH FREQUENCY 300 MHz - 3 GHz SUPER HIGH FREQUENCY 3 GHz - 30 GHz EXTREMELY HIGH FREQUENCY 30 GHz - 300 GHz     Frequency Spectrum

67. Example Which frequency band is considered as audio frequency ? Answer: 30 Hz to 30 kHz 430-440 MHz belong to what frequency range? Answer: UHF

68. Example What are included in the high frequency range? Answer: 3 MHz – 30 MHz In what frequency range does 7.095 MHz A3J signal belong to? Answer: HF

69. Example In what frequency range does the 144 MHz phase shift keying signal belong to? Answer: VHF What are included in the ultra high frequency range? Answer: 300 MHz – 3000 MHz

70. Example What does the acronym VHF represent in reference to frequency ranges? (UHF? HF?) Answer: Very High Frequency What are included in the Very High Frequency range? Answer: 30 MHz – 300 MHz

71. QUESTIONS ?

72. SAMPLE QUESTION What is the unit of Voltage? What is the symbol used to denote Voltage? Answer ! Volt V

73. SAMPLE QUESTION What is the unit of Current? What is the symbol used to denote Current? Answer ! Ampere I

74. What is the unit of Resistance? What is the unit symbol used to denote Resistance? Answer ! Ohm Greek letter omega, SAMPLE QUESTION Ω

75. What is the unit of Capacitance? What is the unit symbol used to denote Capacitance? Answer ! Farad F SAMPLE QUESTION

76. SAMPLE QUESTION What is the unit of Inductance? What is the unit symbol used to denote Inductance? Answer ! Henry H

77. SAMPLE QUESTION What is the unit of Power? What is the unit symbol use to denote Power? Answer ! Watt W

78. SAMPLE QUESTIONS What is the unit of Frequency? What is the unit symbol used to denote Frequency? Answer ! Hertz Hz

79. Contact Me: GENARO “GENE” A. CUARESMA DU1RNA MAKILING AMATEUR RADIO SOCIETY (DX1MK) Email: shooter483 at yahoo dot com Mobile: [phone]

80. Thank You for Listening And Good Luck! 73