- #1

- 15

- 0

## Homework Statement

This isn't a homework question, just one I can't get the correct answer to. The circuit diagram is attached, and I need to find the voltage at V.

## The Attempt at a Solution

Assume the voltage drop across each diode is 0.6V. Let V_5 be the voltage drop across the current source. Using the voltage polarities and current directions I assumed in the diagram, I get the four equations below.

i_1 = 0.005 A. (1)

By KCL, i_1 = i_2 + i_3. (2)

Applying KVL to the left inner loop and then Ohm's law gives: -2000i_2 + V_5 = 0.6V. (3)

Applying KVL to the outside loop and then Ohm's law gives: -1000i_3 + V_5 = -9.4V. (4)

When I solve these 4 equations I get:

i_1 = 0.005 A

i_2 = -0.00167 A

i_3 = 0.00667 A

V_5 = -2.73 V

The problem is that i_2 is negative, which means that current is flowing backwards through diode D_1.

What have I done wrong?

Many thanks in advance.

Note: I know that the voltage at V (relative to ground) is the voltage across resistor R_1, which is i_3*1000 (V). But I suspect that my value for i_3 is wrong because my value for i_2 is wrong.

Last edited: