1. Passive elements in the frequency domain
Consider a resistor, R, in the time domain i
+ v -
ECE 201 Circuit Theory I

2. Taking the Phasor Transform,
The Phasor Voltage is equal to the Resistance times the Phasor Current
ECE 201 Circuit Theory I

3. Phase Information
The voltage has the same phase as the current – there is no phase shift.
ECE 201 Circuit Theory I

4. Consider an Inductor, L i
+ v -
ECE 201 Circuit Theory I

5. ECE 201 Circuit Theory I

6. Compare the resistor and inductor
+ v -
+ v -
Treat jωL as if it were an R
ECE 201 Circuit Theory I

7. Phasor Diagram Im Re V “leads” I by 90 or I “lags” V by 90 j = 190
ECE 201 Circuit Theory I

8. Phase information
ECE 201 Circuit Theory I

9. Consider a capacitor, C i
+ v -
ECE 201 Circuit Theory I

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11. Compare the resistor and capacitor
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+ v -
Treat 1/jωC as if it were an R
ECE 201 Circuit Theory I

12. Phasor diagram Im Re I “leads” V by 90 or V “lags” I by 90 j = 190
ECE 201 Circuit Theory I

13. Phase information
ECE 201 Circuit Theory I

14. ELI the ICE man Phasor Diagram
Capacitor, C
Inductor, L
V(E) leads I
ELI
I leads V(E)
ICE
ECE 201 Circuit Theory I