cheap/chinese LPSU's - minefield?

[the_doc735]

On 9/24/2018 at 10:11 PM, the_doc735 said:

Another possibility: (for mobo)

https://www.ebay.co.uk/itm/ZEROZONE-Assembled-Ultra-Low-Noise-linear-Power-supply-board-LPS-board-L158-25/131588996943?hash=item1ea350bf4f:g:WU0AAOSwLVZV3ZTL (x4)

+

https://www.ebay.co.uk/itm/220V-200W-R-Core-Transformer-for-Audio-Power-AMP-Amplifier-40V-40V-15V-15V/332071927187?hash=item4d51077d93:g:lhgAAOSwW6JYXplE (x1)

 

could this work? Looking for informed advice please?

 

...just got a reply from the transformer supplier in china and he doesn't know if this will work with those 4 boards!! "Great!"....

No response from the boards supplier so far!

[Superdad]

On 9/24/2018 at 2:11 PM, the_doc735 said:

Another possibility: (for mobo)

...

could this work? Looking for informed advice please?

 

No offense, but based on my reading of your answer-seeking posts this past month I am not confident that you possess the knowledge or skills to properly—and safely—complete a big 4-rail supply as a DIY project.

 

Are you prepared to chose and size for current and voltage the four transformer AC secondaries to ensure that the post-diode DC is above the target regulated voltage enough that even under full-load draw it does not droop to close and fall out of regulation?  And will you optimize the heat sinking and choose high performance thermal pads that will allow for the large dissipation of heat that will be required for each output device?  If your secondary voltages run too high (watch what load they were spec’d at because they will be a lot higher under no load), then you will have more heat to manage—and you need to stay in the limits of your output device.

How about grounding for safety—both the transformer and the chassis to AC?  And  speaking of grounding, will “float” all of your rails and also isolate the DC output jacks from the chassis to preserve that?

 

I could go on, but honestly I think you would be best served—and safest—to pick a prebuilt supply or two and live with them. You asked for informed advise.  There’s my $0.02.  

 

Sometimes people look at DIY power supply component parts and assume it is a simple, just plug the pieces together affair.   Building an average power supply is not rocket science, but it does take some consideration and understanding.

 

[Superdad]

4 hours ago, the_doc735 said:

 

...just got a reply from the transformer supplier in china and he doesn't know if this will work with those 4 boards!! "Great!"....

No response from the boards supplier so far!

 

By the way, I had a look at the transformer you linked to and can tell you right away that it is all wrong for your application.  What are you going to do with two 40V/2.2A secondaries plus two 15V/0.8A secondaries?  Completely useless for an ATX project and an illustration of my point above about you not having the basic knowledge needed to tackle a big DIY LPS project.

I don’t mean that to be harsh or to put you down (not my style).  As a user you are not expected to know all the how of such things.  I understand a very modest amount about power supplies, but as I am not an engineer either, there a million projects I would not dream of tackling.

[the_doc735]

No offense, but based on my reading of your answer-seeking posts this past month I am not confident that you possess the knowledge or skills to properly—and safely—complete a big 4-rail supply as a DIY project?

 

1) Are you prepared to choose and size for current and voltage the four transformer AC secondary’s to ensure that the post-diode DC is above the target-regulated voltage enough that even under full-load draw it does not droop to close and fall out of regulation? 

 

2) Moreover, will you optimize the heat sinking and choose high performance thermal pads that will allow for the large dissipation of heat that will be required for each output device?  

 

3) If your secondary voltages run too high (watch what load they were spec’d at because they will be a lot higher under no load), then you will have more heat to manage—and you need to stay in the limits of your output device.

 

4) How about grounding for safety—both the transformer and the chassis to AC? 

 

5) Moreover, speaking of grounding, will “float” all of your rails?

 

6) Isolate the DC output jacks from the chassis to preserve that?

 

7) I had a look at the transformer you linked to and can tell you right away that it is all wrong for your application. 

 

? What are you going to do with two 40V/2.2A secondary’s plus two 15V/0.8A secondary’s?

 

9) Completely useless [tranny] for an ATX project.

 

I understand a very modest amount about power supplies, but as I am not an engineer either, there a million projects I would not dream of tackling.

 

No offence taken. Many thanks for your opinion.

 

1) I would need help with this, but I am confident.

2) Yes.

3) I would need help with this, but I am confident.

4) Yes.

5) Help needed

6) Yes.

7) Why?

? Connect them to the 4 ZEROZONE L158-25 LPS boards.

9) Why?

 

The L158-25 boards I would ask for are: 3.3v/5v/12v/12v (for the mini-ITX mobo).

 

I thought the voltage range on that tranny was zero –up to- 40V (x2) & zero –up to- 15V (x2)? On that basis, connecting the 2-12v boards to the 40v outputs & the 3.3v/5v boards connected to the 2-15v outputs. You obviously know that this is not suitable and doesn’t work in this way, therefore a constructive and positive response would be to tell me what tranny is appropriate for use with 4 L158-25 boards? That would be more helpful to me, than simply saying “what I picked is useless!”.

 

I was going to purchase a good quality aluminium chassis with fins on both sides [for heat].

I don’t know the load/amperage requirements for the 4 DC mobo inputs! (i.e. 3.3v/5v/12v/12v). I was hoping that the 2.2A & 0.8A would be sufficient? In addition, the 200W tranny would be enough for the PC at boot up (i.e. the peak requirement)?

 

I also intend no offence to you in anyway. Many thanks for these responses. Take Care. 

 

[4est]

2 hours ago, the_doc735 said:

No offense, but based on my reading of your answer-seeking posts this past month I am not confident that you possess the knowledge or skills to properly—and safely—complete a big 4-rail supply as a DIY project?

 

1) Are you prepared to choose and size for current and voltage the four transformer AC secondary’s to ensure that the post-diode DC is above the target-regulated voltage enough that even under full-load draw it does not droop to close and fall out of regulation? 

 

2) Moreover, will you optimize the heat sinking and choose high performance thermal pads that will allow for the large dissipation of heat that will be required for each output device?  

 

3) If your secondary voltages run too high (watch what load they were spec’d at because they will be a lot higher under no load), then you will have more heat to manage—and you need to stay in the limits of your output device.

 

4) How about grounding for safety—both the transformer and the chassis to AC? 

 

5) Moreover, speaking of grounding, will “float” all of your rails?

 

6) Isolate the DC output jacks from the chassis to preserve that?

 

7) I had a look at the transformer you linked to and can tell you right away that it is all wrong for your application. 

 

? What are you going to do with two 40V/2.2A secondary’s plus two 15V/0.8A secondary’s?

 

9) Completely useless [tranny] for an ATX project.

 

I understand a very modest amount about power supplies, but as I am not an engineer either, there a million projects I would not dream of tackling.

 

No offence taken. Many thanks for your opinion.

 

1) I would need help with this, but I am confident.

2) Yes.

3) I would need help with this, but I am confident.

4) Yes.

5) Help needed

6) Yes.

7) Why?

? Connect them to the 4 ZEROZONE L158-25 LPS boards.

9) Why?

 

The L158-25 boards I would ask for are: 3.3v/5v/12v/12v (for the mini-ITX mobo).

 

I thought the voltage range on that tranny was zero –up to- 40V (x2) & zero –up to- 15V (x2)? On that basis, connecting the 2-12v boards to the 40v outputs & the 3.3v/5v boards connected to the 2-15v outputs. You obviously know that this is not suitable and doesn’t work in this way, therefore a constructive and positive response would be to tell me what tranny is appropriate for use with 4 L158-25 boards? That would be more helpful to me, than simply saying “what I picked is useless!”.

 

I was going to purchase a good quality aluminium chassis with fins on both sides [for heat].

I don’t know the load/amperage requirements for the 4 DC mobo inputs! (i.e. 3.3v/5v/12v/12v). I was hoping that the 2.2A & 0.8A would be sufficient? In addition, the 200W tranny would be enough for the PC at boot up (i.e. the peak requirement)?

 

I also intend no offence to you in anyway. Many thanks for these responses. Take Care. 

 

Once again, you do not know enough to know what you don't know. Worse, you are expecting people to spoon feed you all of this...

[the_doc735]

37 minutes ago, 4est said:

Once again, you do not know enough to know what you don't know. Worse, you are expecting people to spoon feed you all of this...

that really helps.

[sandyk]

 

 

Quote

      43 minutes ago, 4est said:

Once again, you do not know enough to know what you don't know. Worse, you are expecting people to spoon feed you all of this...

 

 

that really helps.

This kind of advice may just save your life, or that of a family member. 

We haven't even got into the area of wiring in a suitably rated fuse(s) which could help prevent a fire in the event of a fault condition, or correct earthing where a 3pin mains plug is used, proper insulation standards where the PSU isn't earthed, suitable gauge wire for internal cabling AND appropriate colour of the cabling used to help prevent costly errors when wiring it up. Then there are proper Earthing techniques .(below)

I bet that you didn't know for example that some IEC sockets have a metal strip which is at full A/C mains potential !

 

[the_doc735]

48 minutes ago, sandyk said:

We haven't even got into the area of wiring in a suitably rated fuse(s) which could help prevent a fire in the event of a fault condition, or correct earthing where a 3pin mains plug is used, proper insulation standards where the PSU isn't earthed, suitable gauge wire for internal cabling AND appropriate colour of the cabling used to help prevent costly errors when wiring it up. Then there are proper Earthing techniques .(below)

I bet that you didn't know for example that some IEC sockets have a metal strip which is at full A/C mains potential !

 

many thanks!

Yes, I know about fuses.

yes I know about correct earthing where a 3pin mains plug is used

yes i know about insulation

yes I know about wire gauges

yes I know about colour coding

yes I know about IEC sockets

yes I know about the info in your diagram.

 

Please see my reply to @Superdad  above (4 posts back) for area's that I need help with!

e.g. what is a suitable tranny for,four of these boards?

cheers!

[jabbr]

6 hours ago, the_doc735 said:

Please see my reply to @Superdad  above (4 posts back) for area's that I need help with!

e.g. what is a suitable tranny for,four of these boards?

cheers!

 

 

To start: for your 12V supply, what is the average voltage you want to supply your regulator board?

How many amps do you need for each voltage?

[the_doc735]

16 minutes ago, jabbr said:

 

 

To start: for your 12V supply, what is the average voltage you want to supply your regulator board?

How many amps do you need for each voltage?

thanks!

a few posts back I already said: "I don’t know the load/amperage requirements for the 4 DC mobo inputs! (i.e. 3.3v/5v/12v/12v)."

I don;t know the average voltage? I thought a 12v supply would be OK for a 12v mobo input? In the same way you would buy a 9v wall wart for a 9v appliance.

cheers!

[jabbr]

20 minutes ago, the_doc735 said:

thanks!

a few posts back I already said: "I don’t know the load/amperage requirements for the 4 DC mobo inputs! (i.e. 3.3v/5v/12v/12v)."

I don;t know the average voltage? I thought a 12v supply would be OK for a 12v mobo input? In the same way you would buy a 9v wall wart for a 9v appliance.

cheers!

 

If you don't know, you don't have a way to decide which transformer you need. These are basic questions. Again:

 

What voltage do you want to supply your regulator board? The board is designed to output 12V, what is the input?

[Superdad]

42 minutes ago, jabbr said:

What voltage do you want to supply your regulator board? The board is designed to output 12V, what is the input?

 

Well not only that, but most transformer manufacturers quote the AC output voltage of their secondaries at the max current rating for that winding.  At lower loads the voltage is going to be a lot higher so consideration (and calculation of rectified DC voltage levels) of that  comes in right away, lest the regulator board gets forced to handle a rather large drop.

 

Honestly, given @the_doc735's statement that he "thought the voltage range on that tranny was zero –up to- 40V (x2) & zero –up to- 15V" (trans secondaries don't have a "range" Doc), it is clear that he ought not be trying to design and build a big power supply himself.

I can browse automotive engine catalogs all day, but I'm not going to drop by my local mechanic and ask him to tell me how to specify, assemble, install, and test a cylinder head from a kit of parts. Maybe I'll ask the owner at our local fine restaurant to loan me her chef for an evening to teach me how to cook better. 

 

Sorry to be snarky, but I really think he missed the points of my prior two posts.  So I'll stop now.  

 

 

[barrows]

I am never one to discourage those who are interested in learning to DIY a bit, but a multiple rail, relatively high power,  AC based power supply is not the place to start.

If one is really interested in learning to DIY some power supplies, i would recommend starting with something simple, where there is adequate support.

AMB.org makes some very nice power supply designs available, single and dual rail, and these are adaptable to many different projects.  They also have a forum with very good support, and very good instructions.

Twistedpearaudio.com is another company with DIY designs and complete kits, with forum support at DIYaudio.com.

There are many folks at DIYaudio.com who offer a lot of support for those interested in learning as well, in general.

[jabbr]

3 minutes ago, Superdad said:

 

Well not only that, but most transformer manufacturers quote the AC output voltage of their secondaries at the max current rating for that winding.  At lower loads the voltage is going to be a lot higher so consideration (and calculation of rectified DC voltage levels) of that  comes in right away, lest the regulator board gets forced to handle a large drop.

 

Honestly, given @the_doc735's statement that he "thought the voltage range on that tranny was zero –up to- 40V (x2) & zero –up to- 15V" (trans secondaries don't have a "range" Doc), it is clear that he ought not be trying to design and build a big power supply himself.

I can browse automotive engine catalogs all day, but I'm not going to drop by my local mechanic and ask him to tell me how to specify, assemble, install, and test a cylinder head from a kit of parts. Maybe I'll ask the owner at our local fine restaurant to loan me her chef for an evening to teach me how to cook better. 

 

Sorry to be snarky, but I really think he missed the points of my prior two posts.  So I'll stop now.  

 

 

 

Yeah I read.

 

There are a few issues about optimal PSU design and there's also a lot available on the web. Trying to start at the most basic. Sure you can feed 40V into a 3.3V regulator -- that's called a linear space heater! ?... I haven't gotten to the calculation for heatsink yet  

 

I advise anyone interested in DIY audio to build the DIYAudio ACA first! https://diyaudiostore.com/collections/kits/products/amp-camp-amp-kit?variant=7072933085218

[Superdad]

7 minutes ago, jabbr said:

Sure you can feed 40V into a 3.3V regulator -- that's called a linear space heater!

 

LOL.   

Assuming the reg's input range extends that high and that it even would be possible to heatsink that much drop.  And assuming a full-wave rectifier network, the raw DC voltage will of course be about 1.4 times that 40V!

[the_doc735]

1 hour ago, jabbr said:

 

If you don't know, you don't have a way to decide which transformer you need. These are basic questions. Again:

 

What voltage do you want to supply your regulator board? The board is designed to output 12V, what is the input?

well, if you mean "the mains" its 220v UK?

[the_doc735]

46 minutes ago, Superdad said:

 

Well not only that, but most transformer manufacturers quote the AC output voltage of their secondaries at the max current rating for that winding.  At lower loads the voltage is going to be a lot higher so consideration (and calculation of rectified DC voltage levels) of that  comes in right away, lest the regulator board gets forced to handle a rather large drop.

 

Honestly, given @the_doc735's statement that he "thought the voltage range on that tranny was zero –up to- 40V (x2) & zero –up to- 15V" (trans secondaries don't have a "range" Doc), it is clear that he ought not be trying to design and build a big power supply himself.

I can browse automotive engine catalogs all day, but I'm not going to drop by my local mechanic and ask him to tell me how to specify, assemble, install, and test a cylinder head from a kit of parts. Maybe I'll ask the owner at our local fine restaurant to loan me her chef for an evening to teach me how to cook better. 

 

Sorry to be snarky, but I really think he missed the points of my prior two posts.  So I'll stop now.  

 

 

I have rebuilt cylinder heads. Yes, stop now if you are not a good teacher! I cannot interpret your questioning, Same happened at school in the 1960's so I was branded as 'thick'; thank god some teaching methods have moved on to recognise the different way in which people learn, in those days though I had to learn away from school in my own time because the teachers were incompetent and only had time for those bright pupils that cottoned-on immediately and the rest were left to rot! Same here I think? Nothing's changed really! Best if you stop now, that is the easy way out. Just because I don;t know about r-core transformers doesn't mean I can't learn about them! I can learn if presented in a way I understand. I told you the issues I was having difficulty with and now you want to wash your hands of me, typical response. Go then, but I will find out one way or the other, come hell or high water! I am determined to build this thing, in the same way I proved the school teachers wrong decades ago. e.g. playing instruments, cooking, household electrics, car repair, bring up baby, decorating, building PC's, repairing domestic appliances, property maintenance, etc. etc.

[the_doc735]

laugh laugh laugh!!! ~ yes laugh at me, I'm used to that bullshit all my life, don't give a shit anymore Superdad. Glad your not my dad actually; given your tendency to driving people to suicidal thoughts again! 

[sandyk]

9 hours ago, the_doc735 said:

Please see my reply to @Superdad  above (4 posts back) for area's that I need help with!

e.g. what is a suitable tranny for,four of these boards?

cheers!

 

 How much experience do you have using a soldering iron with electronic components, and using a DMM for continuity and voltage testing etc.?

 Do you own a DMM ?

Your questions so far suggest that you are well out of your depth with the construction of a multi supply rail higher power PSU.

 Nobody is laughing at you as we all had to start somewhere, which was with much simpler projects than this very ambitious one..

[jabbr]

41 minutes ago, the_doc735 said:

well, if you mean "the mains" its 220v UK?

 

No. You don't feed 220v AC into your regulator board. What do you feed into your regulator board. Lets assume the board puts out 12v, has a ground, and has an input. What is the input?

[the_doc735]

12 minutes ago, sandyk said:

 

 How much experience do you have using a soldering iron with electronic components, and using a DMM for continuity and voltage testing etc.?

 Do you own a DMM ?

Your questions so far suggest that you are well out of your depth with the construction of a multi supply rail higher power PSU.

 Nobody is laughing at you as we all had to start somewhere, which was with much simpler projects than this very ambitious one..

been using DDM since the 1970's & soldering iron on toys to amps to replace broken components etc. Cheers!

[the_doc735]

32 minutes ago, jabbr said:

 

No. You don't feed 220v AC into your regulator board. What do you feed into your regulator board. Lets assume the board puts out 12v, has a ground, and has an input. What is the input?

I really appreciate what you are trying to do here, but "the penny still hasn't dropped"? The input from the transformer to the board? Maybe a diagram would help? Cheers!

[Ralf11]

Yes, draw a diagram of components on what you have 735 and post it - that will help people help you

[the_doc735]

this is the only info I have about the board: https://www.ebay.co.uk/itm/ZEROZONE-Assembled-Ultra-Low-Noise-linear-Power-supply-board-LPS-board-L158-25/131588996943?hash=item1ea350bf4f:g:WU0AAOSwLVZV3ZTL the regulators are built in.

 

They can make me custom voltage: 3.3v/ 5v/12v/12v output boards. They don't mention any input voltage to the boards?

[jabbr]

18 minutes ago, the_doc735 said:

I really appreciate what you are trying to do here, but "the penny still hasn't dropped"? The input from the transformer to the board? Maybe a diagram would help? Cheers!

 

You need to figure this out before you can begin to build a power supply.

 

There is no "one right answer -- it depends on the board you select. 

 

Draw a schematic of the circuit you are planning -- there is no one answer, it depends on the design you select.

 

If you need help, look up examples of linear power supply designs on the web. There are many examples.