Reference Guide

Equation Reference 5-15
DC Inductor Voltage (2, 14)
These equations approximate the dc voltage induced in an inductor by a change in current in a certain time interval.
Equations:
V V–
I∆
t∆
-----
 
 
⋅=
V∆ If– Ii–= t∆ tf ti–=
Example:
Given: L=100_mH, V=52_V, ∆t=32_µs, Ii=23_A, ti=0_s.
Solution: ∆I= -0.0166_A, If=22.9834_A, tf=32_µs.
RC Transient (2, 15)
Equation:
V Vf Vf Vi–( )– e
t
–
R C⋅
------------
⋅=
Example:
Given: Vi=0_V, C=50_µF, Vf=10_V, R=100_ ω , t=2_ms.
Solution: V=3.2968_V.
RL Transient (2, 16)
Equation:
I
1
R
----
Vf V f Vi–( )– e
t
–
R
⋅
L
-------------
⋅
 
 
 
⋅=
Example:
Given: Vi=0_V, Vf=5_V, R=50_ ω , L=50_mH, t=75_µs.