The Basic Elements and Phasors Part 1 AC ch 14-a.pptx

The Basic Elements and Phasors

Part 1

1. The Basic Elements and Phasors Part 1 Imam Ja'afar Al-Sadiq University Computer Technical Engineering First Class Asst. Lec . Sadiq M.B Fakhruldeen

2. OBJECTIVES Become familiar with the response of a resistor , an inductor , and a capacitor to the application of a sinusoidal voltage or current. Learn how to apply the phasor format to add and subtract sinusoidal waveforms. Understand how to calculate the real power to resistive elements and the reactive power to inductive and capacitive elements. Become proficient in the use of a calculator to work with complex numbers .

3. DERIVATIVE FIG. 14.1 Defining those points in a sinusoidal waveform that have maximum and minimum derivatives.

4. DERIVATIVE FIG. 14.2 Derivative of the sine wave of Fig. 14.1.

5. DERIVATIVE FIG. 14.3 Effect of frequency on the peak value of the derivative.

6. RESPONSE OF BASIC R To A SINUSOIDAL VOLTAGE OR CURRENT FIG. 14.4 Determining the sinusoidal response for a resistive element. FIG. 14.5 The voltage and current of a resistive element are in phase.

7. RESPONSE OF BASIC L TO A SINUSOIDAL VOLTAGE OR CURRENT FIG. 14.8 Investigating the sinusoidal response of an inductive element. FIG. 14.9 For a pure inductor, the voltage across the coil leads the current through the coil by 90°.

8. RESPONSE OF BASIC C TO A SINUSOIDAL VOLTAGE OR CURRENT FIG. 14.11 Investigating the sinusoidal response of a capacitive element. FIG. 14.12 The current of a purely capacitive element leads the voltage across the element by 90°.

9. RESPONSE OF BASIC R, L, AND C ELEMENTS TO A SINUSOIDAL VOLTAGE OR CURRENT FIG. 14.13 Example 14.1(a). FIG. 14.14 Example 14.1(b).

10. RESPONSE OF BASIC R, L, AND C ELEMENTS TO A SINUSOIDAL VOLTAGE OR CURRENT FIG. 14.15 Example 14.3(a). FIG. 14.16 Example 14.3(b).

11. “ ELI the ICE man.” Note that the L (inductor) has the E before the I ( e leads i by 90°), and the C (capacitor) has the I before the E ( i leads e by 90°) for a capacitor, i C leads v C by 90°, or v C lags i C by 90°. * for an inductor, v L leads i L by 90°, or i L lags v L by 90°. The voltage and current of a resistive element are in phase

12. EXAMPLE 14.1 The voltage across a resistor is indicated. Find the sinusoidal expression for the current if the resistor is 10 . Sketch the curves for v and i . a. v 100 sin 377 t b. v 25 sin(377 t + 60°)