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    Thoughts on this power supply kit

    Good day folks. Since I currently lack a bench power supply at work, I thought I'd take matters into my own hands and get one myself. Since it would see relatively little use with the workload I get around here, I didn't want to blow a lot of cash on it and get a "proper" one, so I turned to Ali once again and did an experiment to see just how much I can cheap out to build a lab PSU, so I found THIS.

    Of course, I could've gone with one of those DPS modules and a laptop power brick or something, but what attracted me to this kit is that it's linear which albeit inefficient AF is supposedly better than a switching module due to low noise on the output....I already had some discussions on this in my threads about the two DPS-based PSU builds I did and how I was worried about the noise on the output being unsatisfactory for electronics...

    Probably the only thing wrong with this particular kit is the caps, obviously, since they're bound not to be of particularly high quality, which can be worked out, but other than that the circuit seems legit enough. Even better: they offer the schematic, so if anything goes pop it should be easy enough to repair
    Wattevah...

    #2
    Re: Thoughts on this power supply kit

    Remember you still need beyond the meters:

    - heatsink
    - Transformer

    Probably should work well enough, and as said, you have schematic, you can fix. And the capacitors are running at 100Hz so you probably don't have to worry about them for a while.

    I really should mod my homemade PSU to be a bit more power efficient, this one should be much more power efficient than mine...

    Comment


      #3
      Re: Thoughts on this power supply kit

      you cant set your output until it's on because it has no displays.
      what happened to the other psu project in the dead tree??
      or was it a rack case - i forget

      Comment


        #4
        Re: Thoughts on this power supply kit

        It's another crappy Xiaolin design, basically a knock off (cheaper) of the generic Mastech/Manson bench PSU's. Does this inspire confidence: "When the load is open or light load, the voltage will have a relatively large overshoot when the original circuit is shut down."

        The power transformer(s) are going to be expensive.
        1. dual 12V-15V 1A transformer
        2. multitap 15V/23V/31V 5A transformer

        It's the usual project that looks good -but is a money-pit.

        Finish your DPS power supply...

        Comment


          #5
          Re: Thoughts on this power supply kit

          I only do occasional repairs as a hobby this is the psu im using it seems too work fine im powering it using a old printer supply
          https://www.ebay.co.uk/itm/Digital-c...wAAOSwLIJe2yQz

          Comment


            #6
            Re: Thoughts on this power supply kit

            Originally posted by eccerr0r View Post
            Remember you still need beyond the meters:

            - heatsink
            - Transformer
            I already have a couple of meters and I was planning on swiping the transformer out of an UPS or power amp my old dinosaur colleague has lying everywhere around his cave here and wouldn't miss - the same one who slaughtered that last Sammy TV I wrote about


            Originally posted by stj View Post
            you cant set your output until it's on because it has no displays.
            what happened to the other psu project in the dead tree??
            or was it a rack case - i forget
            There's actually two of them: the one in the "dead tree" as you call it is the finished one and uses a DPS5015 if memory serves. It works, but can probably be better as some of you pointed out, since the transformer is just chilling there with no grounding or Y cap anywhere (I forgot where this was supposed to go) The IEC 13 inlet I used on the back DOES have its earth prong wired to the chassis of the transformer, but the outlets themselves don't actually use this where I currently live, so it's floating.

            The rack case uses two separate circuits to power two DPS5020 - THIS is the one which is still "in progress" So far, I was able to source 3 identical UPS transformers for these projects. The one which has two of them side by side of course weighs a ton

            Originally posted by redwire View Post
            It's another crappy Xiaolin design, basically a knock off (cheaper) of the generic Mastech/Manson bench PSU's. Does this inspire confidence: "When the load is open or light load, the voltage will have a relatively large overshoot when the original circuit is shut down."

            The power transformer(s) are going to be expensive.
            1. dual 12V-15V 1A transformer
            2. multitap 15V/23V/31V 5A transformer

            It's the usual project that looks good -but is a money-pit.

            Finish your DPS power supply...
            Good to know. Like I said, I have one working DPS supply and I'm struggling to finish the other one with two modules in it. As some of you know, I'm both a slow worker and like to get hung up on details and features I may not need. Combine that with the little free time I've got and a lot of project of mine are still on hold, including this one. I mostly wanted to build this one "properly", especially since it's made out of metal and so I kept researching Y caps for so long that actually forgot what I need and have to go over my original thread to re-learn about that
            Wattevah...

            Comment


              #7
              Re: Thoughts on this power supply kit

              you dont want the outlets grounded to mains - that would stop you putting them in series etc and could even ground your target circuit in a dangerous way.
              so just grounding the transformer frame is best.

              Comment


                #8
                Re: Thoughts on this power supply kit

                Originally posted by Dannyx View Post
                Good to know. Like I said, I have one working DPS supply and I'm struggling to finish the other one with two modules in it. As some of you know, I'm both a slow worker and like to get hung up on details and features I may not need. Combine that with the little free time I've got and a lot of project of mine are still on hold, including this one. I mostly wanted to build this one "properly", especially since it's made out of metal and so I kept researching Y caps for so long that actually forgot what I need and have to go over my original thread to re-learn about that
                And, if i recall, a great dad that does every diy for you...
                [joking]

                Comment


                  #9
                  Re: Thoughts on this power supply kit

                  Originally posted by stj View Post
                  you dont want the outlets grounded to mains - that would stop you putting them in series etc and could even ground your target circuit in a dangerous way.
                  so just grounding the transformer frame is best.
                  Yes, that's how I did it with both the "log" and the metal one: metal chassis and transformer shell to PE - I wasn't going to put the GND of the DPS modules to earth as well.
                  I haven't tried it yet, but I guess it's possible to connect the regulated output of one DPS module with the GND of the other one to create a split supply ? Of course, both modules would have to be set to the same output, say +15v and -15v....
                  Originally posted by megaraider View Post
                  And, if i recall, a great dad that does every diy for you...
                  [joking]
                  Yes, good 'ol pops is in charge of the cases and machining stuff which needs to look good on the end product, since I'm not the most skilled with measuring, drilling and cutting
                  Wattevah...

                  Comment


                    #10
                    Re: Thoughts on this power supply kit

                    You might be setting the bar too high or trying to do too much with the power supply projects. I do this all the time, so I never finish projects

                    Lower the bar- less current or voltage or # channels.
                    For most of my bench work I don't go over about 25V/1.5A so a LM317 does the job, or that cheap-ola "0-30V 2mA-3A" PSU kit does good with only one transformer winding needed.

                    But how can you work without a grounded bench? Mains leakage current is on everything so it's not good.

                    Comment


                      #11
                      Re: Thoughts on this power supply kit

                      Originally posted by redwire View Post
                      But how can you work without a grounded bench? Mains leakage current is on everything so it's not good.
                      I was thinking of running a long earth lead to the nearest plug in my house which actually IS earthed, put a mains plug on the end and plug that in whenever I work My bench has a metal frame, so I'd use a wire lug on the end to attach it down somewhere which would ground the frame and then branch off from there if the specific application calls for it...
                      Wattevah...

                      Comment


                        #12
                        Re: Thoughts on this power supply kit

                        if you do that - i used to do that building pc's
                        make sure you put abig resistor in series.
                        470k > 4.7meg

                        so you remove static, but dont get a big bang if something shorts

                        Comment


                          #13
                          Re: Thoughts on this power supply kit

                          I really should mod my homemade bench PSU to be more efficient, not only for efficiency but to stop frying the pass transistor...

                          Comment

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