morpheous87

Are there some safety measures for shortening the +/- outputs of the PSU? Also where is apropriate to put a fuse before the regulator and how much A to be? And one more question. The Voltage regulator is working perfect. The current regulator also work, but when the potenciometer is nearly at the beggining (few mAs) the current limit led lit and the voltage goes to almost 0V ( with 15-16V regulated for example). So is there something wrong with the current regulator or it's normal?

I did the schematic, and it works fine. Now I'm going to make another one with aim to make +/- power supply. What I have to do for that, should changes have to be made on the board?

For what purpuse are the 3 trimpots? For what ajustments? And is there a way for fine ajustment of the Voltage and Current.

This is PicMaster's PCB. I have a question about the PDF. The white print on page 3 and the PCB connection on page 6 aren't same. The parts names and their places are different. I think the white print on page 3 is the correct one, but am I right? EL_power_supply.pdf

I didn't want to use 2N3055 because of the TO-3 package. I'm not familiar with it, and I don't know how to connect it. As I saw the collector is the steel case. So, should the steel case be separated from the heatsink or not, and how to connect it(especially collector)? The BD139's heatsink should be separated from the others one, but should it be separated brom BD's case?

My aim is only to check the boards, if they work I'll take the nessessary transformer.

I want to ask, can I meke the circuit and use a transformer (for example 22V) just to try if everything is OK with the board. And after that to order the transformer which will be used. Is that possible, and if is, what to expect from the circuit to be sure all is OK.

I'm going to do this PSU in 3A version with 30V 250VA transformer (with an idea for +/- PSU). So I have some questions before i start constructing it. How big should be the heatsink fot the TIP3055 transistros, and should the BD139's heatsink be separated from TIP;s one? Should the heatsink be separated from transistors' body, and from the Ground. P.S. These are my home made PCBs :

How much VAa should be the transformer for 2x5A power supplies?

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

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

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

I printed the PCB from PicMaster's file, I think it should be mirrored. So I opened it in Photoshop and mirrored it. Than save it like PDF. Today I printed it, but it's with smaller size. My ask is, should the PCB mirrored, and that size shoud it be. Or just give a ready printable file. Thanks.

In PicMaster's scheme are used 1x12000uF 63V capacitor or 2x6800uF 63V capacitor. Can be used something smaller or on lower voltage? There ones cost much, and hard to find.

So there isn't problem if 200VA is used. I know that it costs more, but ony that one I found, for now. Thanks!

Is there a problem if the transformer is 200VA?

Can I get higher volatage than 24VDC with lower current <3A ?

Thank's for the info. So I can use a transformer with lower output voltage (24V) till i find apropriate one.

I have one transformer that confuses me. See the label on it and the ouput voltage it makes. Isn't the label 24/91 W means 24V 91 W ?

I have some transformers, and one of them has 31,5V output without a load. Can it be used for the scheme?

What is the maximum voltage which can be used from the transformer? Does the corpuse of the transistor should be separated from the heatshink?

I looked in your project, and I have some questions. Can 24V input from transformer be used? And can 2N3055 be used instead of TIP3055?

Thanks PicMaster, that's what I was looking for. Everything looks great. I'll etch the board soon, and try it out.

I looked up trough this topic, and as s final result I'm pretty much confused. There are a lot of question and answers, different version of the schematic and so on. I's hard for to find real working scheme with ready echable board (my english is not perfect and that makes problems...). My appeal is to link, a working version with the nesessary files, which i can use to build the board ( a ready printable file will be great). I can be single or double sided,but single sided is prefered. Thanks!!

Heya, I'm going to make this project. My question is, does everything work and are there any nesessary modification in the project posted here?