# What is Dependent source: Definition and 30 Discussions

In the theory of electrical networks, a dependent source is a voltage source or a current source whose value depends on a voltage or current elsewhere in the network.Dependent sources are useful, for example, in modelling the behavior of amplifiers. A bipolar junction transistor can be modelled as a dependent current source whose magnitude depends on the magnitude of the current fed into its controlling base terminal. An operational amplifier can be described as a voltage source dependent on the differential input voltage between its input terminals. Practical circuit elements have properties such as finite power capacity, voltage, current, or frequency limits that mean an ideal source is only an approximate model. Accurate modelling of practical devices requires using several idealized elements in combination.

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1. ### Engineering Solving Circuit Equations: A Struggle

I am having a hard time solving this. Letting \$i\$ be the current flowing into ##R_3##, ##i_1## the current flowing through ##R_1## and ##i_2## the current through ##R_1##—and the node between R3 and R1 be e_1; Using KVL and KCL, I've managed to find that ##i + I = i_1 + i_2## Hence...
2. ### Engineering Dependent source problem using KVL

Hi all, I was trying to solve this but I'm stuck as you can see in my notes below: Using simulator the I1=3.125 A | I2=-1,857 A | I3=4,375 A and Power of the dependent current source = -46.875 W Any idea, what could be wrong ?Thanks.
3. ### Engineering Determine if the dependent source of the circuit delivering power or....

Hi all ! I want a confirmation for this exercise please. The circuit: This is my try: https://www.docdroid.net/EFuTDMp/new-doc-2019-10-03-234340-1-converted.pdf -- Thanks
4. ### Engineering Transient circuit analysis problem with a dependent source

Hi all, I tried to solve this, but I can't find the R(equal). I use the following method. The circuit: For t<0 the switch is closed so the iL(0-)=4 A For t>0 it opens and the iL(∞)=0 A Now, I want to find the value τ=L/R(equal) Then I will use the: iL(t) = iL(∞) + ( iL(0-) - iL(∞) )* (...
5. ### Solve Vo: Voltage Nodal Analysis w/ KCL Equation

I'm asked to solve for Vo for this equation. I've set the bottom node to be my reference node before applying nodal analysis. When included in the KCL equation for node at Vb, will the dependent voltage source 20iΔ be negative since the current through that element is leaving node C? Say, the...
6. ### Engineering Problem with series RLC circuit and dependent source

Homework Statement here is my problem : Homework Equations like usual, the problem is related with RLC circuits and transients The Attempt at a Solution [/B] from here, the solution is obviously wrong because from the solution, its alpha should be -300 and not -0.4...and from the...
7. ### Finding R_Thevenin involving dependent source

Homework Statement Homework Equations Impedances: Inductor = jωL; Capacitor = 1/jωC The Attempt at a Solution I attempted to excite the circuit with an Io = 1A source, and then from Zc = 1/jX2 justify Vx = (1)(Zc) Thus, substituting our found Vx and then doing a source transformation, we...
8. ### Finding Thevenin Equivalent with Dependent Source

Homework Statement I am trying to find the Thevenin Equivalent of this circuit Homework Equations Using KCL and node voltage The Attempt at a Solution I found the open circuit voltage for the thevenin voltage so far by the mesh current method, and now I am trying to find the closed circuit...
9. ### Finding a current in a circuit with a dependent source

Homework Statement My problem is in the images attached. Essentially, I just want to find ## I_s ##. Homework Equations ## V = IR ##[/B]The Attempt at a Solution I already have the original solution using KCL, which tells me that ## I_s = 4 A## and that ## I = 1 A##, but I was trying to do...
10. ### [HELP]Thevenin Norton with dependent source in Transistor

Homework Statement My teacher gave me a method to find Impedance of Thevenin and Norton. Here is her method: she removed Indepentdence source (voltage is closed, current is open) and did not put V external ( so the dependent source did not working because of no source). And she find resistance...
11. ### Find current using KVL (with dependent source)

Homework Statement Homework Equations V = IR Kirchoff's Voltage Law The Attempt at a Solution [/B] Top loop - a Bottom right - b Bottom left - c Ix = x KVL: top: a(6000) + (a-b)(2000) + 5x - 10=0 bottom right: -5x + (b-a)(2000) + b(3000) + (b-c)(4000) = 0 bottom left ...
12. ### Engineering Thevenin equivalent circuit with dependent source

Homework Statement http://oi57.tinypic.com/263tqvr.jpg I decided to try using mesh currents for thisFirst mesh is IA, second IB, third, ICSo I have the equations IA = 500 μA 1310 IB + 100(IA - IB) = - 4*10-5V2 IC = -80IBAre these equations correct so far? I get the feeling they're not
13. ### Source Transformation to find i_x

Homework Statement I'm to use source transformation to find the current through the 24 Ohm resistor 2. The attempt at a solution I used source transformation on the left 12V source and got a .5A current upwards. The 24 and 30 ohm resistor are in parallel so I found an equivalent resistance of...
14. ### Thévenin equivalent with dependent source

Hello, I had read in my textbook that when a dependent source is in a circuit, and you wish to find the thévenin resistance, then the method to solve for the thevenin resistance is to turn off the independent sources and add an external voltage, then find the external current. The external...
15. ### Archived Superposition to solve circuit with dependent source

Homework Statement Assume that Vs = 10V , R1 = 1.7Ω , and R2 = 0.50Ω. Find the current I in the figure using the superposition principle. Homework Equations Superposition principle KCL, KVL V=IR Current and voltage dividers The Attempt at a Solution I = I' + I'' First replacing the...
16. ### Finding Vx, Is, and Power in a Dependent Source

Homework Statement Find Vx, Is and power on the dependent source. The Attempt at a Solution http://s17.postimg.org/3x4hszzkf/002.jpg
17. ### Calculate the power consumed by dependent source

Homework Statement calculate the power consumed by dependent source Homework EquationsThe Attempt at a Solution The 10A source does not build a supermesh. Loop 3: (i3-i2).(1/10)=0 => i3=i2 Loop 2 : i2=10(A) i3=10(A) vx.(10)=10=> vx=1(V) (node voltage) also for loop 2 ...
18. ### Is a resistor a dependent source?

Is a resistor a voltage-controlled current source? WHY? I think it is but I don't know whether I'm correct.
19. ### Dependent source with 2 other sources (using superposition), mesh

Homework Statement http://imageshack.us/a/img834/5512/homeworkprobsg216.jpg Using superposition, find i.Homework Equations V = IR, KVL, KCL, Nodal / Mesh analysis, voltage division, current divisionSuperposition procedureThe Attempt at a Solution So this time the dependent source is a...
20. ### Mesh/Nodal analysis with superposition, dependent source and diff frequencies

Hi, I am preparing for my circuits final and I am having trouble with this question. Can someone guide me through it? I am trying to solve this using phasors. I know I will have to use superposition since the circuit contains sources with different frequencies. So first I start of...
21. ### Finding the Thevenin Equivalent with a dependent source

Hi! I'm having some difficulty understanding how to go about solving the following problem. I'm a beginner at this and am completely lost. I've seen a few similar problems that could be solved with node/current analysis, but I don't really understand if or how to apply that here. Can someone...
22. ### Dependent source parallel an inductor with a sinusoidal source

an independent source with a forcing function modeled by cos(500t) is in series with an 100 ohm resistor. A dependent (current controlled) source is placed across the remaining resistor terminal and ground. A 0.3mH inductor is in parallel with the dependent source. The value of the dependent...
23. ### Power generated by dependent source

Homework Statement Determine the power generated by the dependent source in the circuit shown below: Homework Equations Ix=V/R Pgen=V*I The Attempt at a Solution I made an equivalent circuit, but it may not be correct (resistors in parallel?): Ix=-(12V/(12/7)Ω)=-7A 2Ix=2(-7a)=-14A...
24. ### Thevenin Equivalent with dependent source

hi :smile: I'm having some trouble figuring out the Thevenin equivalent for this circuit. As you can see, there are two dependent sources (current dependent current source & voltage dependent voltage source) and no independent source. I have started trying to analyse the circuit by...
25. ### Thevenin Equivalent Circuits with Dependent Source

May anyone please help with the method of getting Thevenin Equivalent resistance (RTH) for the attached circuit. I have already found VTH to be 8V. Sim
26. ### Engineering Time Constant RC circuit with dependent source

Homework Statement Homework Equations T = R*C The Attempt at a Solution I have no idea how to go about this. I know that T=R*C in a RC circuit
27. ### Thevenin Equivalent with a dependent source

Find the Thevenin Equivalent circuit between A and B the circuit is in the attachments... i don't know how to start and don't know what it meas "Between A and B" and i never encountered a problem with a dependent source. Thanks...
28. ### Ac analysis with dependent source

Homework Statement Determine I1 independent AC voltage source 10 cos 10^5t inductor 60mH capacitor 5nF dependent voltage controlled voltage source 3Vx Homework Equations KVL & KCL The Attempt at a Solution \begin{array}{l} - 7.071 + 6000I_1 - j6000I_3 = 0 \\...
29. ### Thevenin's Theorem - Dependent Source + Resistor

Hey, I'm having a bit of difficulty with this one. I spoke to my professor specifically about this problem, he worked through it, I understood him, and I worked through it later in the day. I still get it, I worked through it, and there's step at the end that we both did differently. It seems...
30. ### Power in voltage dependent source

I have some problems determining the power dissipated in the dependent source,mostly because my equations aren't right, I think...So,I was wondering,if someone could help me getting my equations right...Here's what I've come with so far: I0=v2/10;7I0=132 In the left node point, the voltage...