0-30V Stabilized Power Supply

[audioguru2]

Now I understand better, thank you for the clarification.

I put 68 ohms and resolved that. 

BTW, Texas send me 3 samples of the tle2141, it's a good choice for who is having trouble finding it.

I am glad that increasing the value of R17 fixed your problem and it is wonderful that you received samples of the opamps.

 

[thiagoas]

The things are getting very hot with the BD139 here 

It goes up to 80ºC
Too little heatsink?

It was able to control current down to 500uA, this is very nice. Thank you all for this great project.

 

[liquibyte]

The things are getting very hot with the BD139 here 

It goes up to 80ºC
Too little heatsink?

It was able to control current down to 500uA, this is very nice. Thank you all for this great project.

Yeah, your heatsink has way too little surface area here, these get hot.  Go back a few pages and see what I used for mine.  While these are probably overkill, even then they get pretty warm to the touch.

 

[audioguru2]

Yes, your heatsink is much too small.

 

[thiagoas]

Something went wrong now  ???

U2 is always at 30 V in the out pin, the opamp is ok, voltage in the pin 3 is variating normally.


I'm lost 

Edit:
Found it! Those crappy transistors burned without even get much warm.

Fake parts? Never heard of this brand.

 

[audioguru2]

Some fake transistors have some tin foil inside instead of a transistor chip.
In Google I found your transistors being sold in China:

View attachment 42136

 

[thiagoas]

LOL, I expect find something worst inside that (yeah, I'm open it).

Now I'm with ST transistors.  ;D

 

[liquibyte]

LOL, I expect find something worst inside that (yeah, I'm open it).

Now I'm with ST transistors.  ;D

I used these from Digikey.  ON Semi and no issues so far.

 

[thiagoas]

This one looks way better.

 

[audioguru2]

I have never bought any parts from ST Micro. They are Italian and I am Canadian.

 

[thiagoas]

And I am Brazilian, which gives me very little choise buying components.  :'(

 

[thiagoas]

Look the difference.

 

[audioguru2]

Look the difference.

The MJ21194 has very powerful specs on its ON Semi datasheet. But yours has a tiny little chip inside and is marked Mexico and with the same date as the cheap ones sold by a Chinese company shown in Google Images. Why are American transistors made in Mexico sold cheaply in China?? Because they are fakes?
The name Motorola Semi was changed to ON Semi in 1982 when all their transistors became marked "ON" instead of "M". Maybe counterfeiters don't know that.

Here is an expert who discusses fake transistors: http://sound.westhost.com/fake/counterfeit-p1.htm

 

[peterk]

@ Audioguru

I took the liberty to tidy up your list and schematic.
If this meets with your approval then perhaps Site Moderators can pin it to the first page if at all possible.


Parts List:
Named both "Rev 6 July/2014" ( I found it confusing when one was rev5 and other rev2 ). I think that date should be included in the name;  "latest" is ambiguous.
Fixed colour red on D10, D13
Kept LED as D12
Labelled zener D13 since it was an addition after the original project
Listed differences for TLE2141 and MC34071

Schematic:
Added labels to RV1, RV2, RV3
Labelled zener D13
Designate D7

I have copied the "Best Of" out of the first 147 pages and made it into a .pdf for troubleshooting one's own.





Troubleshooting_30V_PSU.pdf

 

[liquibyte]

@ Audioguru

I took the liberty to tidy up your list and schematic.
If this meets with your approval then perhaps Site Moderators can pin it to the first page if at all possible.


Parts List:
Named both "Rev 6 July/2014" ( I found it confusing when one was rev5 and other rev2 ). I think that date should be included in the name;  "latest" is ambiguous.
Fixed colour red on D10, D13
Kept LED as D12
Labelled zener D13 since it was an addition after the original project
Listed differences for TLE2141 and MC34071

Schematic:
Added labels to RV1, RV2, RV3
Labelled zener D13
Designate D7

I have copied the "Best Of" out of the first 147 pages and made it into a .pdf for troubleshooting one's own.

The PDF is a nice addition.  I'll let others weigh in on the schematic and parts list first but I think that these would make a nice addition to the front page and may help people with many of the issues that have been seen while building and setting these up.  MIght be nice to have a TOC with links of the questions to the relevant parts of the PDF and the answers for easy navigation.

 

[peterk]

Thanks Liquibyte. 147 pages condensed into 10. Most of the questions ppl were asking were repeated throughout this topic so hopefully the answer may be found herein.

I'll see if a TOC is workable. After reading 147 pages, deciphering, copying, editing, keeping what's relevant, I'm bushed.

 

[liquibyte]

Thanks Liquibyte. 147 pages condensed into 10. Most of the questions ppl were asking were repeated throughout this topic so hopefully the answer may be found herein.

I'll see if a TOC is workable. After reading 147 pages, deciphering, copying, editing, keeping what's relevant, I'm bushed.

I'm looking into adding bookmarks and a TOC using an editor I have.  Never really used it so I'm having to do a little research.

 

[audioguru2]

Thanks, Peter.
I did not organize the changes since I never built and tested this project, I simply added my opinion about how to fix its problems. The original project had many errors.

 

[peterk]

OK audioguru, but since you attach the list and cct now and then you'll decide which one you'll go with then.

@ liquibyte, I have the TOC done, I'll post it tomorrow.

 

[peterk]

I have added an index to the above posted Troubleshooting Guide.
Redownload it again if you'd previously done so in the last 24 hours.