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Multisim Hw help!

Hey guys i am learning how to use multisim in my circuits class and i need some help on some HW i was given. I am to make circuits with this given .

 

1. VL = 3.928 V, IR3 = 872.191 μA

 

 2.VL = 1.364 V, IR3 = 4.283 mA  

 

3.VL(max) = 1.888 V, VL(min) = 446.228 mV

 

given:   Is(max) = 106.159 mA, Is(min) = 102.414 mA.

 

If someone could show me how this is done and explain it that would be great! 

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Without a schematic diagram we have no idea what the circuit looks like, the values of any components, what kinds of components are in the circuit and how they are connected. That makes it impossible to show or explain anything.

 

We like to help people learn but of course we will not do your homework for you. The best way to get help is to clearly explain the problem, to show what you have tried, to point out the parts which do not work as expected, and to ask very specific questions about the parts you do not understand.

 

In your post I see some inconsistencies, even with the limited information. Line 3 has minimum and maximum values for VL but the value is Line 1 is outside that range.  Some values appear to have 6 significant digits while others have 4.

 

Have you evaluated this circuit analytically? Working thourg a circuit with pencil and paper (to 1-2 significant digits) is a valuable tool for both understanding and for validating the simulation.

 

Lynn

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Thank you for the reply and i understand what you are saying, but this is literally all the professor gave me, and all he told use was download multisim and do this. I asked for help but he was really no help at all, i would try if i even knew how to start which i dont so sorry, but im totally lost because this is the only information given to me.

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I am sorry, too, because there is not enough information to solve the problem.

 

For example Is has no relationshiip with anything else. The relationship between VL and IR3 is inverse (IR3 decreases as VL increases), but nothing says the relationship is linear. One straight line will fit those two points, but so will an infinie number of other curves. And, as I pointed out previously, The limits on Vl in Line 3 are inconsistent with the value in Line 1.

 

I could probabaly create a circuit which meets those conditions, but it would not mean much. Create a current source for Is with a value of 104 mA. Wire both ends to ground. Solve the equation which results from assuming that Lines 1 and 2 repersent two points on a straight line. Create a voltage controlled current source for IR3 and arrange the circuit so that VL (and an offset voltage, if needed) are the inputs and it follows the straight line. Set the value of VL within the limits in Line 3.

 

My guess is that this is NOT what the professor has in mind, but I would claim that it meets the specifications you have posted.

 

Ordinarily, we do not do homework assignments, but in this case either you have badly misunderstood the professor or he assigned an ill-defined problem.

 

Lynn

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