0-30V Stabilized Power Supply

[9waste9]

ok audioguru , i will listen to you so is this the new design ??

http://www.electronics-lab.com/forum/index.php?action=dlattach;topic=19066.0;attach=16230;image

also is this the part's list ?

http://www.electronics-lab.com/forum/index.php?action=dlattach;topic=19066.0;attach=16238;image

or this one

http://www.electronics-lab.com/forum/index.php?action=dlattach;topic=19066.0;attach=16240;image

please confirm .

Also i am planning to use the 3055 power transistor in to-220 package with a heatsink , instead of to-3 package , since im a poor guy

 

[audioguru2]

Hi Waste,
The revised power supply uses two output transistors.
The TIP3055 in the plastic TO-220 case is not allowed to get as hot as the metal TO-3 case.
Therefore a very big heatsink will be needed.

Here (again and again) are the latest schematic and parts list:

View attachment 41279

View attachment 41280

 

[pecok]

This is my version of the PSU , All tested all working no problems complete with PCB and BOM aslo with connection drawing, I mounted the transistors on a seperate PCB but you don't have to use the PCB you can just hard wire them.

Hi,
i've build this one from PicMaster, but on first attempt i got little firework with fog, both U1 and U2 are gone (cracked) does anyone have advice what can be wrong? i have C8 ~ 20000uF

could it be due to power transistors? (transformer, and 2n3055 's are the only parts which survived from my last attempts)

How can i troubleshoot it?
a) can i remove OPAMPS?
b) can i disconnect power transistors?
c) what else i can do?

 

[audioguru2]

U1 has nothing to do with any transistors. It is an 11.2V reference that is fed power through a 10V zener diode so its power supply is only 30V.

U2 operates with a +41.7V total supply. Its max allowed supply is 44V.

Opamps smoke and crack if their power supply voltage is connected backwards or if the supply to an opamp is AC instead of DC.

Corrected math.

 

[pecok]

thank you audioguru

 

[PicMaster]

Hi,
i've build this one from PicMaster, but on first attempt i got little firework with fog, both U1 and U2 are gone (cracked) does anyone have advice what can be wrong? i have C8 ~ 20000uF

could it be due to power transistors? (transformer, and 2n3055 's are the only parts which survived from my last attempts)

How can i troubleshoot it?
a) can i remove OPAMPS?
b) can i disconnect power transistors?
c) what else i can do?

I never had that problem, Have you checked that the bridge rectifier is correct ?
I used one like this from here
http://www.rapidonline.com/Electronic-Components/Discrete-Semiconductors/Bridge-Rectifier-Diodes/4A-8A-In-line-bridge-rectifiers/29673

It's like audioguru stated it must have been power supply voltage is connected backwards or the op-amps aren't the correct ones. Has it is remover U1&U2 and see what voltage you have got on pins 7&4.

Or have you found your error or a fault, means you thaked audioguru but you do not say if problem solved

I know my design works 100% otherwise I would of not published it

 

[fikic]

I am planning to use 24V/250VA transformer for this project, since this is the only one I have now. Is this ok? What is the difference if I use 10000uF instead of 12000uF for C1 (for 3A design)? Has anyone tryed to draw single-sided PCB for new 3A project?

PS: I drew PCB in Ki-cad. Can someone, please take a look at it and tell me if it's good? If it is, then others might use it too.

dokumentacija.zip

 

[audioguru2]

I am planning to use 24V/250VA transformer for this project, since this is the only one I have now. Is this ok?

Then the output voltage at 3A will be only about 25VDC instead of 30VDC and when you turn the voltage-adjust knob higher then the output will not be regulated and will have lots of ripple.

What is the difference if I use 10000uF instead of 12000uF for C1 (for 3A design)?

You won't notice any difference. Big electrolytic capacitors have a very wide tolerance. The 10,000uF one might be 15,000uF and the 12,000uF one might be only 8,000uF.

 

[PicMaster]

I am planning to use 24V/250VA transformer for this project, since this is the only one I have now. Is this ok? What is the difference if I use 10000uF instead of 12000uF for C1 (for 3A design)? Has anyone tryed to draw single-sided PCB for new 3A project?

PS: I drew PCB in Ki-cad. Can someone, please take a look at it and tell me if it's good? If it is, then others might use it too.

Yeah I did and you can download it from here, It's single sided and it can be 3A or 5A your choice

 

[morpheous87]

Yeah I did and you can download it from here, It's single sided and it can be 3A or 5A your choice

What's the difference betwenn 3A and 5A projects. Something in the elements or the transformer?

 

[audioguru2]

What's the difference betwenn 3A and 5A projects. Something in the elements or the transformer?

The transformer must supply 28VAC at 200VA or 30VAC at 212VA.
There must be three output transistors with emitter resistors and a pretty big heatsink.
The heatsink for the driver transistor Q2 must be a little bigger.
The current sensing resistor R7 must be 0.27 ohms/10W.

 

[morpheous87]

So, the PicMaster's PCB need a little change for the third transistor?

 

[audioguru2]

So, the PicMaster's PCB need a little change for the third transistor?

Yes, there must be space for the 3rd output transistor. I can't remember where the emitter resistor is located.

 

[fikic]

Ok, I re-drawn my PCB, so it's jumper-free. I also strengthened all tracks, so this is my final version I guess. I will try it once this week and I will report.

dokumentacija.zip

 

[PicMaster]

So, the PicMaster's PCB need a little change for the third transistor?

Yes it will require a little Mod, I only built the 3A version I've never really as the need for 5A, The mod is esy to do you can just hardwire the third transistor onto the exsisting tracs just solder the emitter resistor straight onto the pin of the transistor. I can mod the pcb to take the thr third transisor

 

[morpheous87]

It would be nice to have a 5A ready for etching PCB.

 

[fikic]

If you have Kicad, you can try mod my verison to 5A. I can try it too, but not this week.

 

[karthikeid]

hi fikic

u need to smooth down the tracks, cover the track edges of layout properly or else while
etching it will be a problem.

 

[fikic]

This is becouse of .pdf file. When I print it it's ok. I am working on strenghtening pads.

 

[fikic]

Here it is:

pcb.pdf