How to Correctly Find the Thevenin Equivalent Circuit?

[Phillipe]

Homework Statement

Find the Thevening Equivalent Circuit for the following circuit:

Homework Equations

KVL, KCL.

The Attempt at a Solution

First of all, I calculate the current in the middle mesh, which I'll call i2:

$$- j25 = ({i_2} - {i_1})(3 + j4) + {i_2}(10)$$

where i1 is the current defined by the current source. Once I've got i2, I multiply that by 10 to get the voltage in the 10 ohm resistor, and after that I calculate Vab using:

$${V_{ab}} = j25 - 10({i_2})$$

However, the result is incorrect (should be 22,2 V with a 98º angle). What am I doing wrong? I've used the same method with other circuits and it worked just fine.

 

[gneill]

You'll have to show your work. Using your technique I reached the correct result.