1. Alternating Current
Module

2. Upon completion of this module, you will be able to do the following:
Objectives
 Upon completion of this module, you will be able to do the following:
1. Calculate the peak and effective voltage or current values for an AC waveform.
2. Calculate the phase relationship between two AC waveforms.
3. Describe the voltage and current phase relationship in a resistive AC circuit.
4. Describe the voltage and current transients that occur in an inductive circuit.
5. Define inductive reactance and state how it is affected by frequency.
6. Describe the voltage and current transients that occur in a capacitive circuit.
7. Define capacitive reactance and state how it is affected by frequency.
8. Explain the relationship between voltage and current in the following types of AC circuits:
• RL circuit
• RC circuit
• LC circuit
• RLC circuit
9. Explain the following terms as they relate to AC circuits:
• True power
• Apparent power
• Reactive power
• Power factor
10. Explain basic transformer action.

3. Figure 1 – Conductor moving across a magnetic field

4. Figure 2 – Angle versus rate of cutting lines of flux

5. Figure 3 – One cycle of alternating voltage

6. Figure 4 – Frequency measurement

7. Figure 5 – Amplitude values for a sine wave

8. Figure 6 – Voltage waveforms 90° out of phase

9. Figure 7 – Waves in phase

10. Figure 8 – AC waveforms

11. Figure 9 – Resistive AC circuit

12. Figure 10 – Voltage and current in a resistive AC circuit

13. Figure 11 – Factors affecting the inductance of a coil

14. Figure 12 – Inductor voltage
and current relationship

15. Figure 13 – Capacitors

16. Figure 14 – Charging and discharging a capacitor

17. Figure 15 – Capacitors in parallel

18. Figure 16 – Capacitors in series

19. Figure 17 – Voltage and current
in a capacitive AC circuit

20. Figure 18 – Summary of AC circuit phase relationships

21. Figure 19 – Series RL circuit and vector diagram

22. Figure 20 – Series RL circuit with waveforms and vector diagram

23. Table 1 – Series R and XL Combinations

24. Figure 21 – Parallel RL circuit with waveforms and vector diagram

25. Table 2 – Parallel R and XL Combinations

26. Figure 22 – Series RC circuit with vector diagrams

27. Table 3 – Series R and XC Combinations

28. Figure 23 – Parallel RC circuit with vector diagrams

29. Table 4 – Parallel R and XC Combinations

30. Figure 24 – Series LC circuit with vector diagram

31. Figure 25 – Parallel LC circuit with vector diagram

32. Figure 26 – Series RLC circuit and vector diagram

33. Figure 27 – Parallel RLC circuit and vector diagram

34. Figure 28 – Power calculations in an AC circuit

35. Figure 29 – RLC circuit calculation

36. Figure 30 – Power triangle

37. Figure 31 – Basic components of a transformer

38. Figure 32 – Transformer action

39. Figure 33 – Steel laminated core

40. Figure 34 – Cutaway view of a transformer core

41. Figure 35 – Transformer winding polarity

42. Figure 36 – Transformer turns ratio

43. Figure 37 – Tapped transformers

44. Figure 38 – Importance of an isolation transformer

45. Figure 39 – Autotransformer schematic diagram

46. Figure 40 – Current transformer schematic diagram

47. Figure 41 – Potential transformer.

48. Supplemental Art

49. Course Map

50. Left-Hand Rule for Generators

51. RMS Amplitude

52. What’s Wrong With This Picture?

53. AC Circuits

54. Turns and Voltage Ratios