Superposition theorem with ideal current source

The circuit in question 3 has thevenins being applied to it. My first step was to put r1//r3 as one resistor. I then removed RL. I'm not sure if I include r13 in My r thevenin equation because it is not in an enclosed loop. How would the r thevenin be calculated


P_20160322_191237 shows my current work with the combined resistor

I can't really follow what you've described (it would be much better just to post your working rather than to talk about it) but you need to:

1. find $R_\theta$ by replacing all current sources with open circuits, and all voltage sources with short circuits, then calculating the resistance as measured across the load terminals of that modified circuit

2. find $V_\theta$ by analysing the unmodified circuit to compute the voltage across an open circuit load. In this case, you will be computing the voltage due to the current of 1.44 mA through a resistance of 33 || (27 + 12) k ohms.

I can't really follow what you've described (it would be much better just to post your working rather than to talk about it) but you need to:

1. find $R_\theta$ by replacing all current sources with open circuits, and all voltage sources with short circuits, then calculating the resistance as measured across the load terminals of that modified circuit

2. find $V_\theta$ by analysing the unmodified circuit to compute the voltage across an open circuit load. In this case, you will be computing the voltage due to the current of 1.44 mA through a resistance of 33 || (27 + 12) k ohms.

Thanks for the reply!

Here is my work for $R_\theta$

And wouldn't the total resistance be (33||12) +27 K ?

Thanks for the reply!

Here is my work for $R_\theta$

And wouldn't the total resistance be (33||12) +27 K ?

eh?

You need to calculate $R_{\theta}$ = (R1 + R2) || R3

No. I think that you are allowing the circuit diagram to confuse you as to what is in parallel with what. See uberteknik's answer above.

Also, I think my description of the calculation of the required voltage may confuse you, if you don't look at the circuit carefully. Across which resistor do you need to calculate the Thevenin voltage?

I really don't understand this. The way my diagram is it should be R1+R3 then || R2. Although the diagram I created is probably wrong if that is no the correct way to do this

Voltage across R13..

.. altering putting them in parallel