Ohm's Law & Non-Linear Circuits

In summary, Ohm's law is only applicable to linear circuits, while most loads in life are non-linear. However, we can still use Ohm's law to analyze circuits with non-linear elements by breaking them down into smaller stages and using tools like Laplace transform theory. This is also what a good Spice program does. However, the accuracy of the results depends on the accuracy of the models used for the individual components in the circuit.
  • #1
derek181
57
2
Ohm's law only applies to linear circuits. If most loads in life are non-linear, what use is ohm's law?
 
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  • #2
Hooke's Law is only good for perfectly elastic and massless springs. What use is it?
PV=nRT is only good for ideal gasses, of which there are none. What use is it?

Get the idea?
 
  • #3
So we model non ideal systems in an idea way and neglect the small error?
 
  • #4
Why do you think most loads are non-linear? Most loads are largely resistive. Even when the output of a circuit is driving a complex impedance there are plenty of linear elements to analyze in there.
 
  • #5
You can model the non-linear circuit by taking it in stages: the switch is open (mechanical or transistor) - now carry out a linear analysis. The switch closes - use Laplace transform theory to find the transient signal.

This plus the final state of the previous analysis (states of capacitors and inductors) allows your to carry out an analysis of the next stage. Repeat ad nauseum. This is what a good Spice program does. The limitations are based on the models for the individual properties of the components being used - wrong specs, wrong results.

Oh - and if you want perfection, then you must know the lengths of wires, the resistivity, and the qualities of all of the connections, soldered and unsoldered.
 

FAQ: Ohm's Law & Non-Linear Circuits

What is Ohm's Law?

Ohm's Law is a fundamental law in physics that describes the relationship between voltage, current, and resistance in an electrical circuit. It states that the voltage across a conductor is directly proportional to the current flowing through it, with the proportionality constant being the resistance of the conductor.

How is Ohm's Law applied in linear circuits?

In linear circuits, Ohm's Law is used to calculate the voltage, current, or resistance in a circuit when the value of the other two are known. This allows for the prediction and analysis of the behavior of the circuit.

What are non-linear circuits?

Non-linear circuits are electrical circuits where the relationship between voltage and current is not proportional. This means that Ohm's Law cannot be applied to these circuits, as the resistance is not constant.

What are some examples of non-linear circuits?

Examples of non-linear circuits include diodes, transistors, and semiconductor devices. These circuits exhibit non-linear behavior due to their internal components and the way they are designed to function.

How are non-linear circuits analyzed?

Non-linear circuits are analyzed using mathematical models and simulation software. The behavior of these circuits can be predicted and analyzed by understanding the characteristics of their components and the principles of non-linear circuit analysis.

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