A little help with my university project please...

[muki55]

It's still wrong and completely useless!.

whats wrong there's nothing wrong with the diagram. i try it in tina pro
its completely fully functional.

 

[audioguru]

whats wrong there's nothing wrong with the diagram.

The two positive supplies don't have a main 2200uF filter capacitor. Therefore when loaded they will have severe voltage fluctuations as ripple.

Two bridge rectifiers are used when only one is needed.

 

[muki55]

The two positive supplies don't have a main 2200uF filter capacitor. Therefore when loaded they will have severe voltage fluctuations as ripple.

Two bridge rectifiers are used when only one is needed.

ok, sorry tnx,
here's updated

 

[audioguru]

Your simulator didn't catch the mistake of the missing filter cap because the regulators weren't loaded.

You still have two bridge rectifiers when only one is needed.

 

[Pedro Martins]

muki55:

1st:
Use ONLY ONE bridge rectifier if you want it working is real life;
2nd:
The configuration of your design is for use when you have 2 isolated secondaries. In this case, it's a normal secondary with central tap;
3rd:
Just for curiosity, I tested in my bench your design! Great! Only noise and heat!!
Unfortunally, I didn't take any picture to show the output waveform here, sorry. But is very ugly!

So, my design is the best for any need, as far the output current don't exceed 1A. The 2.200uF cap in the positive can be changed with 4.700uF if some ripple is noted if both +5 and +6V are loaded.
The transformer can be 8-0-8V 30VA. This it is enough and don't make regulators heat!

This is my opinion and my help.

Cheers,

Pedro Martins

 

[Hero999]

ok, sorry tnx,
here's updated

Haven't you been listoning?

Read the thread from the beginning, you only need bridge one rectifier and it's highley recommended you put the switch and fuse in the live/phase/hot/line conductor and not the neutral/cold conductor.

 

[HiTech]

LOL LOL Just like kindergarden in here!

 

[morrissey]

Hello everyone, after changing to LM7906 everything worked perfectly..
In a few hours i'm going to give it.
Thanks to everyone for your help!

 

[bigkim100]

holy crap

University!!!???...I think I could have designed and built a power supply like this one in grade 6...
what the hell is going on!!??!!

 

[bigkim100]

what the hell...redux

And you guys literally just designed this guys University project for him....from scratch, that he was to design himself!
I hope you all get a passing grade from his teacher!
....SHAMEFUL!

 

[audioguru]

University!!!???...I think I could have designed and built a power supply like this one in grade 6...
what the hell is going on!!??!!

1) Teachers don't teach anymore.
2) Textbooks don't explain anymore.
3) Students don't learn anymore.

 

[morrissey]

This power supply is just a part of the whole project...
The main subject of the project is to build an Electrocardiograph (ECG Amplifier)
and i needed some help with the power supply because i had it wrong.

Maybe you are upset because nowdays through internet i could find a solution to a problem in 30 minutes and not in 10 days where i would have to seek through libraries and asking teachers how should i do it.

And in my case i already had tried to build it alone and starting from zero i was very close to the correct solution without asking anyone...

And finally you should come and see the greek educational system and how things work in the greek universities...For example one team who game their project and it was warking pefrectly instead of 10/10 the teacher gave them 8/10 because a sticker on the box wasn't perfectly horizontial....And that team had the most complete and good-working project....

 

[Nigel Goodwin]

This power supply is just a part of the whole project...
The main subject of the project is to build an Electrocardiograph (ECG Amplifier)
and i needed some help with the power supply because i had it wrong.

Mains powered machine wired directly to your chest - doesn't sound very 'patient frendly'

And finally you should come and see the greek educational system and how things work in the greek universities.

As you haven't filled your location in, how would we know where you are?.

 

[bigkim100]

Its the REAL WORLD BUSTER!

"And finally you should come and see the greek educational system and how things work in the greek universities...For example one team who game their project and it was warking pefrectly instead of 10/10 the teacher gave them 8/10 because a sticker on the box wasn't perfectly horizontial....And that team had the most complete and good-working project...."

Sorry to pee on your reality guy....but I have worked on a JOB at WORK for weeks, and it has worked perfectly...only to have it rejected by my BOSS because I have silkscreened the labels for the control panel 2mm off to the left. Therefore, I have had to remove the assembly, strip the casing down reprime, repaint, and resilkscreen. I have completed a prototype that has taken me 4 weeks to complete only to have my boss tell me that the line cord is the wrong color!. Ive had customers reject my repairs only because they can see my fingerprints on the case of the unit that I have repaired that were removed with some windex, but not before dressing me down in front of all the other customers waiting for repairs........MAYBE YOUR TEACHERS ARE ATTEMPTING TO LET YOU KNOW HOW THE REAL WORLD WORKS!

"Maybe you are upset because nowdays through internet i could find a solution to a problem in 30 minutes and not in 10 days where i would have to seek through libraries and asking teachers how should i do it."

Um...I dont quite understand your logic...Im supposed to be upset about the fact that I am smarter than you because I would work hard, research in librairies, ask teachers for additional help above and beyond my daily studies.....and find answers to my own questions....instead of having a group of people simply handing the answers to me???!!!!!
....you have a pretty twisted grip on reality there guy.
Im quite certain that your teachers as well as future employers will be thrilled to hear that from you.
As a matter of fact Mr. Ballsey...why dont you provide us with your professors email address, and we'll see for ourselves what he or she thinks of your attitude towards studying, and exactly how you have come to your answers to these projects....Im quite certain that he/sh will be interested in your processes.

 

[bigkim100]

And I hate to pee on you even more, but the projects in your course are only going to get HARDER..and the guys on here are eventually not hand answers to you on a silver platter. As I said, when I was 6, I was making regulated power supplies for CB Radios, Strobes, Color Organs(what can I say...it was the 80's)...with NO HELP...HOW???!! you ask....well I headed down to my local LIBRARY...and leafed through DOZENS of books, probibly spending hundreds of hours there..

 

[dknguyen]

Sorry to pee on your reality guy....but I have worked on a JOB at WORK for weeks, and it has worked perfectly...only to have it rejected by my BOSS because I have silkscreened the labels for the control panel 2mm off to the left. Therefore, I have had to remove the assembly, strip the casing down reprime, repaint, and resilkscreen. I have completed a prototype that has taken me 4 weeks to complete only to have my boss tell me that the line cord is the wrong color!. Ive had customers reject my repairs only because they can see my fingerprints on the case of the unit that I have repaired that were removed with some windex, but not before dressing me down in front of all the other customers waiting for repairs........MAYBE YOUR TEACHERS ARE ATTEMPTING TO LET YOU KNOW HOW THE REAL WORLD WORKS!

So it's not necessarily bad that I am obsessive compulsive about the smallest details like fingerprints and finger oils and colours in my projects? Because it's hell for me when working on my personal projects.

 

[bigkim100]

So it's not necessarily bad that I am obsessive compulsive about the smallest details like fingerprints and finger oils and colours in my projects? Because it's hell for me when working on my personal projects.

Well, that depends....does the perfectionism go so far as your projects are paralysed for a otherwise rediculous reason?.
In the case of the wrong colored ac cord, the cord that I supplied was black, and the one that my boss preferred was grey. Considering that my boss ordered several hundred AC cords in black and none in grey for this project...leaves me scratching my head.
You have to be pretty petty to stop a project from being delivered for that reason. As far as fingerprints on a high gloss black case..ur right....but when you are fixing 20 to 30 units a day....occasionally a few fingerprints may sneak thru...but as long as a wipe with windex gets rid of them...I wont be losing any sleep....or not completing a project because of it.

Besides, I kinda think that you missed the point...I was simply trying to explain that a teacher that takes points off a project for sloppy workmanship, is very much like most bosses. The difference is instead of taking 2 points off your project...your boss may hold up your next pay raise.
Come on douchebag...dont just read...comprehend!

 

[dknguyen]

Come on douchebag...dont just read...comprehend!

No need for name calling.

 

[morrissey]

Sorry to pee on your reality guy....but I have worked on a JOB at WORK for weeks, and it has worked perfectly...

Are you talking serious now? What are you comparing here? Apparently this is your work and you are 45 years old with many years of experience...I'm just 21 with no experience at all and this is the hardest a project would get as i am in the final semester.
I'm not here to steal your job or something... and i really can't understand why this attack. If you have problems with your boss, i'm not the right person to get it out.

Um...I dont quite understand your logic...Im supposed to be upset about the fact that I am smarter than you because I would work hard, research in librairies, ask teachers for additional help above and beyond my daily studies.....and find answers to my own questions....instead of having a group of people simply handing the answers to me???!!!!!

Then why are you in this forum! The purpose i believe here is to help and be helped...Why are you helping other people and you give your valuable knowledge and vise versa?
And no one simply handed the answers to me....The whole summer i had been searching the web and looking for answers, and now in September i accidently bumped to this forum and found "my library" which is way much smarter and more efficient that yours.I had my answer in 30 minutes and you would have had it in 1 day...So i don't think you are the smarter one in this case and the result would be the same, understanding how the circuit works.
Don't try to compare generations...My father was building the same things (CBs and stuff) like you did,when he young, but now he doesn't even know how to write his name in a computer...And tell me which thing is better to know to use these days...Things change to make life easier and earn us some presious time that bosses like yours have taken away.And please don't try defending him...You are practicly taking his place by using these things that he has done to you as an example.
I don't have much experience on life like you do, but i know that life is cruel and the teacher won't learn that to me by cutting down 2 points because of a sticker.And the thing is that no one is said anything about it because the believed that if they did the would upset him and take a smaller mark.Maybe that is what they are really trying to teach us...

 

[tofik]

u can use transformer with center tap and only 1 rectifier
it's simple