I read that the formula for it is (Vr(rms)/ Vdc) * 100%. So I tried to get the Vdc, I tried dividing the Vrms by 10 or by using the formula. Vdc = ( 1-(1/2fRlC)). But I think I'm wrong. I'm sorry, I'm quite new to electronics,You need to show your best attempt at a solution. This is NOT homework done for you.
Thank you very much for your help. I'll do my best on answering.As WBahn stated, draw a picture of what you expect to see for the output voltage.
Then follow these steps. Try to derive from first principles any formula you use. Don't take any formula for granted.
You should use algebraic variables for the following calculations:
1) Calculate the rms AC voltage after the transformer.
2) Calculate the peak AC voltage after the transformer.
3) Determine the peak DC voltage at the load (Output).
4) Calculate the peak current through the load resistor RL.
5) Calculate the cycle frequency and period of the ripple voltage.
Make the first approximation assumption that the ripple voltage is a saw-tooth waveform.
6) Calculate the charge per cycle delivered to the load.
Let us see if you can continue from here on your own.
Thank you for asking. There's an exact answer that was given to us, which is r = 3.90%. I'm a college sophomore at the moment. I guess we just need to give a solution on how the ripple factor became 3.90%Hi there,
First let me just say that the other suggestions in this thread were very good you should consider them seriously. I just wanted to add a little more info here, and one question.
First, are you supposed to find an EXACT answer to this or is an approximation of some kind good enough?
I ask because although there are several approximations for doing this there is an exact solution to this which is a little more difficult but not all that much, and that is because the capacitor is connected directly to the output of the diode bridge. We do often still accept a constant diode voltage drop, and it gets more complicated if we have to use an actual spice diode, but it would be considered very simple if the scale was FROM this bridge rectifier circuit TO a bridge rectifier with cap ESR and other stuff.
So i guess the question really is, what is acceptable for an answer?
You might also mention what year you are in school that might help members answer this question too, and maybe what you have studied in the past.
I'll save the exact solution (which isnt all that difficult) for later after you've thought about all this and tried to answer yourself.
Good luck
Ok one more little detail. What kind of diode model are you using in this problem, is it a constant voltage diode like one that drops 0.7v in the forward conduction mode, or is it 0v in the forward conduction mode, or some other model?Thank you for asking. There's an exact answer that was given to us, which is r = 3.90%. I'm a college sophomore at the moment. I guess we just need to give a solution on how the ripple factor became 3.90%
Thank you for asking. There's an exact answer that was given to us, which is r = 3.90%. I'm a college sophomore at the momen
All of the given diodes are 1N4001Ok one more little detail. What kind of diode model are you using in this problem, is it a constant voltage diode like one that drops 0.7v in the forward conduction mode, or is it 0v in the forward conduction mode, or some other model?
I ask because often these problems are based on ideal diodes not real diodes with reasonably good spice models, and the diode makes a bigger difference than one might think at first because the peak current in the diodes is often larger than we might think in rectifier circuits with no input inductor.
Still waiting to see your best attempt at a solution. We really can't do much more for you until we see that.All of the given diodes are 1N4001
Hi there Eric,hi Zoo and Al.
Now that you have completed the assignment, I can post what LTspice shows.
My maths show 3.21% , close enough.
E
View attachment 276367
Oh thanks for that explanation i was wondering if considering a constant voltage drop for the diode was OK for this problem.Using first order approximations, single diode drop of 0.7V, average DC is 15.3V, ripple is 0.6V, percent ripple is 3.9%.
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