Hello I just started my journey with electronic , so I'm sorry If my questions may be too stupid.... But I draw an schematic of PS. It shuould be correct but I'm not in 100 % sure. My question is about q2. How to compute peak to peak? Vrpp? I Know Vrpp = I / (2f * C) for full vawe but how I can find F -ripple frequency?

 

Welcome to AAC!

how I can find F -ripple frequency?

It's given to you in the problem. Input is 60Hz and you're using a full wave rectifier.

Here's an easier to read version of your schematic:

You've drawn it upside down.

 

Thank you Dennis got it so:

Vrpp = I / (2f X C) = 120 ohm / ( 60 Hz x 1000 uf) = 45.24
Vp = 45.23/2 = 22.6

 

Vrpp = I / (2f X C) = 120 ohm / ( 60 Hz x 1000 uf) = 45.24
Vp = 45.23/2 = 22.6

Are you certain? Are I and R interchangeable?

If you always include units in your calculations, you can find errors more easily.

 

hmmm I'm not certain

 

hmmm I'm not certain

I didn't see the secondary voltage mentioned. How can you determine if the ripple voltage is sufficiently small? Do you think the load resistor is placed correctly?

 

I think is pleaced correctly, but I dont know how to determine :/ I'm working on it one day and have no idea

 

I think is pleaced correctly, but I dont know how to determine :/ I'm working on it one day and have no idea

If the load isn't on the output of the regulator, how can you determine load current? I didn't see where the transformer secondary voltage was mentioned.

 

Hello,

I have compacted the assignment text:



For a) Where are the extra components needed for the regulator? You say a 7812 is to be used, look in the datasheet.
For b) What is the secondairy voltage of the transformer? I do not see it in the assignment.
For c) What do you thint will be the advantage of switching supplies over linear ones?

Bertus

 

Thank you guys for help
For A I just pick up this one
For B It does not say
For c: low noise levels , low cost and reliability

 

draw for ps

 

Hello,

Have a look at page 4 of the attached PDF and tell me what you would answer on C).

Bertus

 

Low waste heat,
High Efficiency
Line transformer can be smaller

 

 

Hello,

You still are wrong with the ripple calculation.
Have a look at the attached unit12 PDF.
Also have a look at the 78XX datasheet for the additional components needed.

Bertus

 

Thank You Bertuz so much
I will calculate step down Transformer for ex 8:1 and then Calculate Post Secondary Voltage So Im going to have V load R load and because of that I can get I load for Vripple and because of those numbers can find a 78XX taht is right?

 

Could you look At question2?

 

You've also drawn the regulator wrong and are still drawing the schematic upside down.

In the first circuit, you had two fuses; now you have none. And you're still not showing the "extra" components mentioned in part a).