Using Norton
theorem, find the constant-current equivalence of the circuit shown in figure 9
below.
Solution
Finding Short Circuit Current (ISC)
To find short
circuit current (ISC), short terminals A and B as shown in figure 10
below.
circuit current (ISC), short terminals A and B as shown in figure 10
below.
From figure 10
above, the total resistance offered to the battery consist of a 10Ω resistance
in series with a parallel combination of 10Ω and 15Ω resistances.
above, the total resistance offered to the battery consist of a 10Ω resistance
in series with a parallel combination of 10Ω and 15Ω resistances.
Finding Norton’s Equivalent Resistance (Ri)
To find Norton’s
equivalent resistance (Ri), since the battery has no internal
resistance, replace the battery with a short circuit as shown in figure 11
below.
equivalent resistance (Ri), since the battery has no internal
resistance, replace the battery with a short circuit as shown in figure 11
below.
From figure 11,
calculate the Norton equivalent resistance (Ri) by viewing through
terminals A and B.
calculate the Norton equivalent resistance (Ri) by viewing through
terminals A and B.
Ri =
10 + (10||10)
10 + (10||10)
= 20Ω
Hence the
equivalent constant-current source is shown in figure 12 below.
equivalent constant-current source is shown in figure 12 below.








