Jump to content
Electronics-Lab.com Community

0-30V 0-3A Latest Data

Guest liquibyte

Recommended Posts

Guest liquibyte

Finally, my post with the Eagle .sch and .brd, full gerbers, and parts list for Digikey in a zip file.  I'm also including many of the pics I took as I was building that were posted both before and after this post.  I'm still not completely done and may add more pics later.  One thing I have changed is the third transformer for the auxiliary circuitry for the temperature sensor and fans and the displays (I wanted a better transformer than the Radio Shack special I had on hand).  Archive attached.




Link to comment
Share on other sites

Guest liquibyte


Edit: I've added a Digikey BOM exported as a spreadsheet as an attachment if you need it.  If you just want to order the parts I have listed, just register or log in to your Digikey account and go to this link and you should be able to checkout from there by clicking the "Create Cart" button at the bottom of the page.

I have not included the mounting kits for the TO-3 transistors, any heat sinks, a case etc.  I figure these things are more of a personal preference and can be had much cheaper elsewhere anyway.  What's on it are all the parts that appear on the actual schematic plus the transformer.  These are the parts I ordered for the final version I built.

As of 08/30/14 this BOM totals $102.32 and prices may change over time.  You can obviously omit the transformer if you have one already or if you want to use another one such as a toroid.  The one I have on the BOM is a large E-I core because it's basically the cheapest one they have that's up to spec.



Link to comment
Share on other sites

  • 2 months later...

I thought a might as well add my own efforts here. I built my own version of the PSU. ( 0-25v 0-3A). As I had a transformer to hand I tweeked the circuit to suit. I replaced the voltage reference circuit as I found the existing one was not that stable! This one is stable over a wide voltage and temperature range. After a lot of testing I changed the ground reference (pin 4) of the voltage control IC to AFTER the current sense resistor. This made a BIG difference to the regulation performance (0.02%). Hope this helps.




Link to comment
Share on other sites

  • 1 year later...

Hi all

Ok, this is my end result. Built and tested and works quite well.

I started with the version posted at the start of this thread. However I had a couple of problems with the current limiter. I didn't have much success with the current limiter clamping the input of U2 - sometimes it would not go right down to 0V, sometimes it would go just below. Just below was a big problem for me - U2 would start to oscillate, with bad consequences for anything connected to the output of the Q4... It would then drive the output high just when I wanted the current limit to become active :'( I should add that I did not use TL2141 or MC34071s, this might be the root of my problem. I fixed this issue with a small change to circuit layout rather than going to expensive opamps.

My mods (compared to the circuit posted on start of this thread):

* current limit - I removed D9. To replace this, I added another BC548 - the base is driven by the current flowing through the current limit LED. The collector of this BC548 clamps the output of U2 (exactly like the existing BC548 driven by the negative rail). This arrangement means we don't care how close to its supply voltage the output of U3 can go. It avoids the possibility of driving the input of U2 out of spec. Clamping the output of U2 is much more like how the integrated voltage regulators work. It seems better to my mind, to keep U2 out of the loop when current limit is active. [Edit: note that U2 will need a small heatsink with this arrangement]

* some rearrangement of the opamp power connections, for all three opamps... U1 & U3 are run via 15V zener diodes, to give a supply of approx 30V. That allows almost any cheap opamp to be used for U1 & U3 (741s or TL071 etc). U2 is connected to unregulated 44V and to the output side of the 0R47. 

* I used a MC33171 opamp for U2. It is high voltage, but much cheaper (they are £0.60 in UK) than TL2141 or MC34071 (both are £5 here). It is a low power IC by comparison.

* 0-30V 4A transformer.

* 2 x 6800uF smoothing caps.a big thanks to the contributors on this thread for their efforts, my project was greatly speeded up by borrowing a lot of their ideas



* I also changed the 0R47 to 0R2, as the 0R47 generated too much heat at 3A for my liking. This also means R18 changes to 330K. These two values are not shown on the schematic here.



Link to comment
Share on other sites

  • 4 weeks later...
  • 3 weeks later...
  • 3 weeks later...
  • 2 weeks later...

hello friends,


I have made power supply as shown this article 30V3A, my problem is, i want  set current  only 200mA limit, and voltage to 30V, i had tried a lots but each time when i connect load, at 150mA of current voltagedrop becomes 15V, is there any problem in my circuit due to this voltage drop appear. basically it should work like upto 200mA it must give 30V after that voltage goes down but before this lime voltage is going down, I m newer in this field, can anybudy sortout my problem.

Link to comment
Share on other sites

  • 2 weeks later...

To use your transformer then many resistor values will need to be re-calculated and changed. The 16.6VAC will have a peak voltage of only 23.5V. The improved circuit is designed to use a 28VAC/4.3A or 30VAC/4A transformer. If you re-design the circuit then with your transformer its maximum regulated output will be about 16.5VDC at about 1.5A. 

Link to comment
Share on other sites

  • 4 weeks later...
On 4.1.2017. at 3:50 AM, audioguru said:

To use your transformer then many resistor values will need to be re-calculated and changed. The 16.6VAC will have a peak voltage of only 23.5V. The improved circuit is designed to use a 28VAC/4.3A or 30VAC/4A transformer. If you re-design the circuit then with your transformer its maximum regulated output will be about 16.5VDC at about 1.5A. 

Thank you very much!

Link to comment
Share on other sites

  • 4 weeks later...

Hi all,

Finally after some months have gone by, my build of the Power Supply is done.

I have used liquibyte schematic Rev. 8 and had made the cirquit board according to the Gerber.zip file he posted here:

0-30V Stabilized Power Supply

Page 88 posted October 6, 2014


I left out D10 and R15 as per his description.

I have plenty of boards leftover if someone has a need for it. There was only one mistake liquibyte made which have outlined in one of the pictures uploaded here.

I was fortunate enough to get a big case with a Toroidal transformer from the scrapyard. Also many parts are recycled from various sources.

Regards, William










Edited by repairman2be
Amended information and photo
Link to comment
Share on other sites

  • 3 months later...

Hi Prithul,

I believe the answer you are looking for is here:

audioguru: Post August 31, 2014

A bit more was mentioned on page 87

Please open a new thread if you want to find out more, as this thread is for completed projects. Thanks

Link to comment
Share on other sites

  • 9 months later...
28.08.2014 в 1:45 утра, Гость liquibyte сказал:

sallala проект
sallala проекта страницы. Предупреждение, не на английском, так что если Вы не говорите на этом языке, translate.google.com это твой друг здесь.







Почему По схеме автора у меня НЕ РАБОТАЕТ ?

Кто это схему создал отвечайте? У меня на выход минус 5-6 показывает ,на 4-7 выход IC3 37.8в ,на АС 25.5в ,на С1 39.8в ,на IC2 39.7в ,на С1 40в 20000мкФ ,на минус С1 и плюс D3 1n4148 показывает минус 1.5в ,что за хрень ,какой придурок этот схему придумал?

Сначало схему отработайте на 100 процент затем людям по советуйтесь , хуй ваша схема не работает ,по схеме видно ошибки польно)))

Link to comment
Share on other sites

Если бы я знал что ваша схема тупит как сам автор как баран ,я сколько деньги на плате не тратил ,почему IC2 и IC3 4-выход не вместе ,почему ваша долбаебьская схема не заработала , время все запчасти куплена новый и праверенно ,почему не работает олени тупые)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...