alternating current

alternating current

• 1.
  Alternating Current
• 2.
  Generating Alternating Current Figure12-1A. Basic AC generator (alternator).
• 3.
  Figure 12-1B-F. ACgenerator inducing a voltage output.
• 4.
  Generating Alternating Current (cont’d.) Figure12-2. Each cycle consists of a positive and a negative alternation.
• 5.
  Generating Alternating Current (cont’d.) Figure12-4. The sinusoidal waveform, the most basic of the AC waveforms.
• 6.
  Generating Alternating Current (cont’d.) Figure12-3. Voltage is removed from the armature of an AC generator through slip rings.
• 7.
  AC Values Figure 12-5.The peak value of a sine wave is the point on the AC waveform having the greatest amplitude. The peak value occurs during both the positive and the negative alternations of the waveform.
• 8.
  AC Values (cont’d.) Figure12-6. The peak-to-peak value can be determined by adding the peak values of the two alternations.
• 9.
  AC Values (cont’d.) Effectivevalue of a sine wave: Erms = 0.707Ep where: Erms = rms or effective voltage value Ep = maximum voltage of one alternation Irms = 0.707Ip where: Irms = rms or effective current value Ip = maximum current of one alternation
• 10.
  AC Values (cont’d.) Relationshipbetween frequency and period: f = 1/t t = 1/f where: f = frequency t = period
• 11.
  Nonsinusoidal Waveforms Figure 12-7.Square waveform.
• 12.
  Nonsinusoidal Waveforms (cont’d.) Figure 12-8.Triangular waveform.
• 13.
  Nonsinusoidal Waveforms (cont’d.) Figure 12-9.Sawtooth waveform.
• 14.
  Summary AC is themost commonly used type of electricity AC consists of current flowing in one direction and then reversing One cycle per second is defined as a hertz The waveform produced by an AC generator is called a sine wave
• 15.
  Summary (cont’d.) The rmsvalue of a sine wave is equal to 0.707 times the peak value The relationship between frequency and period is: f = 1/t Basic nonsinusoidal waveforms include square, triangular, and sawtooth