Solving Circuits Using Voltage & Current Dividers
This example problem uses both the voltage divider and current divider method to solve for unknown voltages, currents, and power values.
This example problem uses both the voltage divider and current divider method to solve for unknown voltages, currents, and power values.
Пікірлер: 73
The analysis for i2 is confusing when explained, but you achieved the correct answer. For those who found it hard to follow, I will try to help explain below... Since we know the current going into the node 1 is 0.5A, we can redraw the circuit using 0.5A as the current source and combine 50R + 10R (series) = 60R. 0.5A (Is = Current Source) --> 20R || 30R || 60R i1 i2 i3 We want to find the the current across the 30R = (i2). **** But first, let's find current across 20R or i1. 30R || 60R = 20R NEW Circuit: 0.5A (Is) --> 20R || 20R i1 (i2 || i3) = ix Current Division: Is * ( ix / ( i1 + ix ) ) i1 = 0.5A ( 20R / (20R + 20R) ) = 0.25A 30R || 60R (w/ i2 across 30R and i3 across 60R) i2 i3 Current Division: Is * ( i3 / ( i2 + i3 ) ) i2 = 0.25A (60R / (30R + 60R) = 0.1667A i3 = 0.5A - 0.25A - 0.1667A = 0.0833 Is i1 i2 i3 Check: KCL Rule 0.5A = 0.25A + 0.1667A + 0.0833A Is = i1 + i2 + i3 0.5A = 0.5A (GooD) Hope this helps :-)
@jcarlos4458
2 жыл бұрын
Very helpful, the video confused me on that part but this cleared it up
@ambition_junkiie83
Жыл бұрын
I’m so glad you took time to clarify this. That part of the video was confusing
@ath6632
Жыл бұрын
but why are the resistors of 40 and 70ohms being ignored? im hella confused by that
@hanaanasr1064
Жыл бұрын
@@ath6632 because current is the same in series and 40 ohm , 70 ohm is in series.
@Lucapro0909
Жыл бұрын
@@hanaanasr1064 now this was the anwsers i was looking for thk u brotha
Life saver, found this right before my midterm. Keep doing what your doing 😊👍
This video was extremely helpful. You should make some on nodal analysis including super nodes, super position, operational amplifiers, and pretty much on the rest of circuits. Thanks for the help.
@engineeringmadesimple8359
7 жыл бұрын
I definitely have those topics on my to-do list, thanks for the feedback!
These videos are extremely helpful to stusents and to teachers also.
This is really amazing that i'm starting to love circuit until i solve problems by myself. :(
Bro, you just make it simple, Thank you so much
Thank you so much for this video! I was about to give up on circuit dividers altogether before finding this. You are a legend.
Thanks from Germany. It helped a lot!
great video, thank you!
Is it possible to use the parallel addition on 60 ohms and 30 ohms instead of 60 and 20 for the current divider part? Thanks
For the resistor where you needed to find the power. After finding the voltage, and given the resistance; why didnt you use the voltage and resistance to find the current (i = V/R) then do P = IV?
Simply amazing!
Thats sick dude nice
man i can't thanks u enough that was really helpful thanks a lot ^^
When calculating V2 which is 0.167A * 30 ohms = 5V wouldn't this be negative since the voltage is flowing in the opposite direction to the current i2??
Thanks... Good tutorial
Really useful. Thank you sir ❤️
great vid, thank you
Thank you!
If I have an 2amp 12volt supply how will this affect the amperage output if I take the voltage down to 6volt . All DC of course.
for finding for finding v1 we take resistance 80 and for v3 we take 10 ohm why
What happened to 70 ohm resistor???
What software you are using
thaanks ♥
Hey thx youuuuuuu
why you calculate i1 instead of i2.
Good job
Sir, my question is, there are many resistors there. How are you going to know that, this one is R1,R2??
Question: How do you get 15 ohms from 20||60? shouldn't it be a third? Edit: I just realized u were adding the resistance in fractions. 1/20 + 1/60 = 1/15 ohms nvm!
Sorry I don't quite understand why you used the value of current i1 to find the value of the voltage at i2...plz anyone with idea plz reply
I don’t get how you got R2. Where did the 20||20 come from?
@Gataroes
5 жыл бұрын
The 60 ohm resistor is parallel with the 30 ohm resistor, so we get ((1/60)+(1/30))^-1 as the equation to get their equivalent resistor.
@engineeringmadesimple8359
5 жыл бұрын
R2 became 20||20 because it was 60||30||20. 60||30 is (60*30)/(60+30)=20 so we now have 20||20.
i like this video
sir your lecture is very good & my question is in Video you want to find v (not) but while solving you wright v1
@engineeringmadesimple8359
5 жыл бұрын
I apologize I did not always use the same notations in the smaller formulas on the bottom as the main formula on top. Hopefully people can see the strategy I was trying to use.
I don't understand. R2 = 30 but why did you make it 15?
@engineeringmadesimple8359
5 жыл бұрын
Hi. I combined the R2=30 with the 50+10 (far right) using the parallel resistor reduction technique. This gave me a new R2 which is 30||(50+10)=30||60=20. Now that I have 20 for my R2, I can use the current divider formula to find the current through the other resistor in the current divider.
good
I thought the formula was V1= (R2/(R1+R2))* Vs Also, what would the formula be if you know V1, Vs and R2 and are solving for R1? And for if you know V1, Vs and R1 and are solving for R2?
@101perspective
3 жыл бұрын
Oh, think I figured out those formulas. R1=((v1/vs)*R2)-R2 R2=((v1/(v1-vs))*R1)-R1 That look about right? Math isn't my specialty...lol.
When finding i2, why do you use the resistor R2 in the numerator instead of the 30 ohm resistor that we're finding the current in?
@engineeringmadesimple8359
7 жыл бұрын
Hi @RedneckDrillMan, great question. For the current divider equation, you use the opposite* parallel resistor in the numerator when finding the current for the branch you are interested in. I accidentally made the i2 in the original circuit the i1 in my current divider, but nonetheless, R2 becomes the opposite branch (15ohm) from the branch I am solving the current for (in our case the 30ohm branch). I hope this helps.
@aHydrasa
7 жыл бұрын
EngineeringMadeSimple Awesome thank you, that helps a lot. The equation in my textbook did not make that clear and I kept getting the wrong answer.
@blackogre7719
7 ай бұрын
@@aHydrasa Super late but you can actually use that formula in a purely parallel circuit, but the trick is, the resistors are in conductance or the reciprocal of the resistor wherein instead of R1 you use 1 / R1. So in formula it would be: ix = isource ( 1 / Rx ) / ( 1 / R1 + 1 / R2 + 1 / R3 + 1 / Rx + ... ) TL;DR. Use the same resistor as numerator to find the current across it but all of the resistors are in reciprocal.
In second problem how that v=20 instead of 60 as shown in diagram!
@engineeringmadesimple8359
5 жыл бұрын
Hi. In Part2 we are reusing Vo from Part1, which we have found to be 20V. Since we know 20V is the voltage drop across the 40 ohm resistor, we can use V=IR to find the current in this part of the circuit.
All I need is for someone to correct me, i'm sure i'm just being dumb, but I LOVED the first part solving for Vo, but when you started solving for I2 that means the direction at which the current flows plays a factor in the equation. You have every thing set up as if the current were flowing positive-negative and i'm confused because I thought current flows negative to positive? what is going on, someone please help me lol
@missdraculaa
5 жыл бұрын
as long as you're consistent it doesn't matter.
What a g👏
Increase Sound volume plz
Dude !! i am lost from first 10 second 😢
@nonayabusiness6170
3 жыл бұрын
Wrong major and class sry to break it to you...
what happens to the 70ohm?
@umangrathore6825
5 жыл бұрын
Exactly whydid the 70 ohm resistor was not used in calculating the i1 in the circuit.
@ath6632
Жыл бұрын
@@umangrathore6825 i guess its a superfluous element(?) im confused too lmao
Dude no one gets how you got R2 and the 20//20 part
@engineeringmadesimple8359
5 жыл бұрын
R2 became 20||20 because it was 60||30||20. 60||30 is (60*30)/(60+30)=20 so we now have 20||20.
the way you did the voltage divider didn't work for a test question I had
@engineeringmadesimple8359
6 жыл бұрын
Would you be able to share your test question? I would double check to make sure you collapsed all of the circuit resistors properly before applying the voltage divider equation.
@engineeringmadesimple8359
6 жыл бұрын
Also, I'd like to note that if you have any active elements in the circuit (capacitors or inductors) and not simply a resistor circuit, this method will not work
Voltage divider formula is Vout =( R2 / (R1+R2))xVin ...why in your care is Vout =(R1/(R1+R2)) xVin?...this is confusing...did you made some different notations?
@engineeringmadesimple8359
5 жыл бұрын
Hi. The voltage divider formula with R2 in the numerator will find the voltage drop across resistor R2. If you want to find the voltage drop across R1 instead (we call this Vo in the video), you simply put R1 in the numerator instead of R1 and you now have V1 (or Vo in the video).
@engineeringmadesimple8359
5 жыл бұрын
Since the resistors are in series you can switch positions between R1 and R2 and use the voltage divider equation for whichever resistor you need and apply the formula this way.
@jakenguyen8066
3 жыл бұрын
@@engineeringmadesimple8359 so just to be clear, with voltage division, you put R for whichever voltage drop you are finding, but with current division, you do the opposite?
horrible, if ur solving for something with given labels (R1, R2) you need to mark that on ur diagram otherwise its confusing af like this vid was