Why there is a minus in the power

  • Thread starter Thread starter electron2
  • Start date Start date
  • Tags Tags
    Power
Click For Summary
SUMMARY

The discussion centers on the difference between the mathematical representation of solutions for differential equations and their application in circuit theory. In normal differential theory, the solution is expressed as v_c(t) = Ae^{s_1t} + Be^{s_2t}, where s1 and s2 are the roots of the homogeneous equation. In contrast, circuit theory employs a modified form v_c(t) = Ae^{-|s_1|t} + Be^{-|s_2|t}, indicating a physical requirement for the voltage to decrease over time. This distinction highlights the influence of physical principles on mathematical modeling in electrical engineering.

PREREQUISITES
  • Understanding of differential equations and their solutions
  • Familiarity with circuit theory concepts
  • Knowledge of homogeneous equations
  • Basic grasp of complex numbers and their role in differential equations
NEXT STEPS
  • Research the physical principles governing voltage decay in circuits
  • Study the implications of complex roots in differential equations
  • Explore the differences between mathematical modeling and physical applications in engineering
  • Learn about the Laplace transform and its use in circuit analysis
USEFUL FOR

Electrical engineers, circuit designers, students of engineering physics, and anyone interested in the mathematical foundations of circuit theory.

electron2
Messages
46
Reaction score
0
when the two roots s1 and s2 that are different of the homogenius equation
in normal diff theory i do

[tex] v_c (t)=Ae^{s_1t}+Be^{s_2t}[/tex]

why why in basic circuit theory we do
[tex] v_c (t)=Ae^{-|s_1|t}+Be^{-|s_2|t}[/tex]
 
Physics news on Phys.org
I'm afraid you'll have to ask that in a "circuit theory" thread. Whatever the reason, It would have to be a physics reason rather than mathematics. I would suspect there is some physical reason why [itex]v_c(t)[/itex] must be decreasing in time. Are the [itex]s_1[/itex] and [itex]s_2[/itex] complex numbers?
 
s1 and s2 are not complex
 

Similar threads

Replies
6
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 17 ·
Replies
17
Views
12K