Electric Circuit Theory Concept

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SUMMARY

The discussion focuses on the characteristics of ideal voltage and current sources in electric circuit theory. An ideal voltage source maintains a constant voltage of 12V regardless of the current drawn, attributed to its zero impedance. Conversely, a real voltage source includes a finite resistance that causes voltage sag under high current. Similarly, an ideal current source is defined by infinite impedance, ensuring that it can supply any amount of current without affecting its output voltage.

PREREQUISITES
  • Understanding of electric circuit components, specifically voltage and current sources.
  • Familiarity with the concept of impedance in electrical circuits.
  • Basic knowledge of series and parallel resistor configurations.
  • Mathematical skills to analyze circuit behavior under varying loads.
NEXT STEPS
  • Study the mathematical modeling of ideal and real voltage sources.
  • Explore the implications of impedance in AC circuit analysis.
  • Learn about Thevenin's and Norton's theorems for circuit simplification.
  • Investigate the behavior of operational amplifiers in relation to ideal sources.
USEFUL FOR

Electrical engineering students, circuit designers, and professionals involved in circuit analysis and design will benefit from this discussion on ideal and real voltage and current sources.

anonymoussome
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Why do we take ideal voltage source to have 0 impedance and ideal current source to have infinite impedance.
Please explain mathematically also!
 
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An ideal voltage source is a voltage source that does not "sag," or decrease in voltage, no matter how much current we pull from it. An ideal 12V source will always produce 12V, even if you pull a hundred billion amperes of current from it.

A real voltage source, on the other hand, has some finite, non-zero resistance associated with it. A model of a "real" voltage source is an ideal voltage source with a resistor in series with it. As the resistor becomes larger, the voltage source becomes less and less ideal -- if you pull large currents, a large voltage drop appears across the resistor, and the output voltage of the source sags.

If you make the resistor very small, or drive it all the way to zero, the "real" voltage source becomes an ideal voltage source. Thus, an ideal voltage source has zero series resistance, or zero impedance.

The same argument applies to current sources having infinite impedance. Can you make those arguments yourself? Remember that the model of a "real" current source involves an ideal current source with a resistor in parallel.

- Warren
 

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