how to wire multiple DC output from one power source ?

Have you thought of bringing them to a terminal strip that has a fan-out strip on one side.

@ddistrbd1

Or a WAGO style connector ...

@will @ddistrbd1 Controversial. If you look closely, you will see the point of contact is very small. If the amperage is very small, then it is acceptable but I would not use it on a 5A DC circuit. The gold standard is twisted and soldered covered in double-walled with adhesive heat shrink, followed by proper wire nuts with knife-edge interiors that groove the wire and create a fairly decent surface area. The cheap wire nuts use round interiors with much less copper in contact.

As an electrician, I would not use those for what sounds like 36VDC at 5A. If it was 36VAC at 5A, it would be marginal.

HOWEVER, the OP question needs to be clarified. He needs to post a schematic. If it is a simple one wire into 4, then the terminal strip @rcc1 proposed is the best solution, but size it for 14AWG and use crimp-on ring connectors. Get a professional crimper. They normally come in a range of sizes for one crimper, you obviously need at least 14AWG, but without knowing your future plans I can't tell you if you need a 14, 12, 10 or a 14, 16, 18. I have crimpers up to 4 IIRC, after that, it's a hammer crimper that I used on my 4/0AWG battery cables (as thick as a man's thumb, designed to carry 400A)

@rcc1 ,Will, Ron, thank you all for your comments ,

rcc1,   I thought about using a busbar connector but the ones I remembered was the white  plastic ones that you daisy chained the terminals with wire , you know , the old ones from my era, then I saw the picture you posted  and realized they have improved on the design dramatically. I ordered a set of 5(with 8 position screw blocks), will see if they fit in the project box.

Will,   I love those WAGO type connectors, in fact I have 10 of them( 2 wires in , 6 wires out), and since the space inside the box for this project is limited, they were my first choice due to their small size. but then I saw the terminal blocks LOL.

Ron,  not often you are wrong but you're right again, the terminal blocks are a better fit , I am aware you don't have the whole picture of what I have in mind but you still managed to nudge me in the right direction, the size of the wire I'm planning to use is 16AWG, as  I mentioned  there will not be high demand on any of the outlets.

As for crimpers, I do have a a good pair and some half decent connectors, I also could use brass lugs if I need to , bought a hammer crimper last year with a whole bunch of different size copper lugs to build a resistance soldering unit, and that was the only time I used it, I forgot all about them until I read your post.

Anyhow, thank you all,  you have helped more than you think you did, I am fully loaded with the parts  for this project, now I'm going to build me a new power supply.

@ddistrbd1 I want to back up a bit. In your OP you said

separate USB modules with outputs of 5V, 9v , 12V . 

USB is 5 volts. What do you really mean by 9V and 12V? If you think some innocent visitor to your house isn't going to plug their $1,500 iPhone into an inviting free charge plug which, if it is 12V will probably destroy the phone, then you are a very optimistic person who must have a great lawyer.

I assume your premise is that the power supply output of 36V will go to 3 different voltage regulators of 5V, 9V, and 12V. That part is fine just don't use a USB connector for the 9V and 12V use a DC barrel connector or similar and label them clearly.

Posted by: @zander

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@ddistrbd1 I want to back up a bit. In your OP you said

separate USB modules with outputs of 5V, 9v , 12V . 

USB is 5 volts. What do you really mean by 9V and 12V? If you think some innocent visitor to your house isn't going to plug their $1,500 iPhone into an inviting free charge plug which, if it is 12V will probably destroy the phone, then you are a very optimistic person who must have a great lawyer.

I assume your premise is that the power supply output of 36V will go to 3 different voltage regulators of 5V, 9V, and 12V. That part is fine just don't use a USB connector for the 9V and 12V use a DC barrel connector or similar and label them clearly.

 

 

 

Ron ,thanks for the correction, what I meant to say was "separate modules" as well as 3 USB modules but my fingers were typing faster than what I was thinking,. so here is the clarification:

I'm planning to have 3 USB outputs( Type C , maybe also  type A),   as well as 3 sets of banana jack sockets/ Binding Post Terminals, 3V. 5V , 9V, .

In case you're interested, right now I am sitting at my desk testing all sorts of modules ( Step Down Buck Converter Charging Modules, adjustable buck modules, etc.) I have 6-7 lined up., before I connect any of them to the 36V power supply, I want to test them with my bench top PS  to verify the actually work , what can I say I'm enjoying it all.

Talk to you soon.

@ddistrbd1 Ok, that sounds better.

FYI, I have many adjustable LM2596 buck/boost modules that I use for power supply applications. I often use one of those in front of a Linear Voltage Regulator. The buck/boost drops the voltage from between 1.2V and 37V to something like 4.5, 7, 14 then the LVR nails it. Those LM2596s are good for 3A, which covers most of my requirements. I have a few different LVRs, they often come in families, and 3.3V and 5V are common, and 9V and 12V are less so but easily found.

When you are done, show us your solution.

Posted by: @zander

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@ddistrbd1 Ok, that sounds better.

FYI, I have many adjustable LM2596 buck/boost modules that I use for power supply applications.

Yes I'm somewhat familiar with them.

Actually those are the modules I was talking about in my post, The first time I used one was in my first 24v power supply and it was a LM2596HV ,with both  AC and DC input, I adjusted it to 12VDC to power the  car USB Charger ,  but there's also another one I like: (LM2595HVS), it only handles DC input of 4.5VDC to ~53VDC as far as I know, 

My linear power supply is done but the output performance was so disappointing that I did not even bother to install it in a proper box. the source of my disappointment was the weak transformer , although it was fun building it but without a bigger transformer, I  couldn't justify using the $30 store bought metal box for it.

@ddistrbd1 Ken, there is NO such thing as an AC to DC version of an LM2596. Stop believing AliExpress BS. I have attached the OFFICIAL data sheet. There are versions to produce 3.3V, 5V, 12V, and adjustable. I have attached the datasheet.

Posted by: @zander

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@ddistrbd1 Ken, there is NO such thing as an AC to DC version of an LM2596.

 

Thanks for the info.

As a newbie hobbyist with next to zero knowledge of  the field I have great amount of respect for you, Dave ,Bill others and totally accept your comment  . 

This is the back of the HV version with AC + in AC- in, can't remember if I  even tested it with my AC  transformer, so you are saying I shouldn't. it will destroy my module? I really don't want to take a chance and blow up my last module.

@ddistrbd1 Show me the other side, doesn't look like a LM2596

I searched for: LM2596HV AC/DC to DC Buck Step Down Converter Adjustable 

The place I ordered these modules :

https://www.aliexpress.com/item/1005001552880166.html?spm=a2g0o.cart.0.0.778d38dap0t1mf&mp=1

https://www.aliexpress.com/item/1005002604132980.html?spm=a2g0o.cart.0.0.778d38dap0t1mf&mp=1

More information on these modules:

LM2596HV

The power module uses the plug-in LM2596HV, a high-voltage version of LM2596, with a maximum input voltage of 50V (limited by the withstand voltage of the filter capacitor) and an external heat sink, which can withstand high current operation. The input end uses a 4A rectifier bridge stack to input AC power, and has a dedicated DC input port, which is commonly used for AC and DC input. The output voltage can be adjusted, ranging from 3.3V to 33V, and the output voltage will vary with different input voltage ranges.

       Input AC voltage AC5V~AC30V or DC5V-48V. Due to the relatively large fluctuation of AC voltage, the recommended AC voltage range has reserved margin. The power module adopts the plug-in LM2596HV with external heat sink, the high-voltage version of LM2596, the highest input voltage is 48V (limited by the withstand voltage of the filter capacitor) and the external heat sink, the output current can work stably at 2.2A output current for a long time. It can work under 3A output current for a short time. The front side of the PCB has the name of the silk-screened terminal block, and the back side also has the name of the silk-screened terminal block. When soldering the leads, please recognize and re-solder to prevent damage.

Parameter:

Input voltage range: AC 5V~30V, DC 5V-48V

Output output range: DC 3.3V~33V

Output current range: maximum 2.2A (the voltage regulator chip can withstand a maximum current of 3A, and can work at an output current of 3A for a short time)

Output power: 35W (maximum)

If it is a genuine part and all claims can be verified, you must admit it is a neat module to have around,the one I am using in my older PS, still works fine never even got warm when I checked ,has a light , so far no issue with it.

here's a better picture:

Hi Ron @zander & @ddistrbd1,

  LM2596 (& LM2596HV) refer to integrated circuits which can be used to make buck regulator, probably originating from Texas Instruments, as they list a data sheet for it.

https://www.ti.com/product/LM2596

.. the term LM2596  does not define the circuit on a PCB .. it is reasonable to expect an LM2596 device on the PCB, but there could be many other things ...

"EC Buying" on AliExpress do list a product which can accept AC or DC

https://www.aliexpress.com/item/1005002604132980.html

And looking at their photo of the board, there is a 4 legged grey rectangular object at the left end that looks suspiciously like a bridge rectifier.

So while I make no claims to have examined this particular product,only the web page, the claim that it accepts AC seems plausible from what is visible in the photo.

If that is indeed a rectifier, then the module should be able to accept AC or DC, the downside for DC  is that the redundant rectifier will add an extra voltage drop of around 1.4V, which will result in more heat dissipation and a higher minimum voltage required for operation.

Hope that explains the mystery.

Best wishes, Dave