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    Bench PSU - Your Suggestions

    Hi everyone,

    I'm an IT guy (not exactly an electronics guy), but I've been trying to learn more about the electronics side of things. It's just that I like the subject

    I have had very good help in this forum with troubleshooting circuit boards, and I must say, there is still A LOT to learn. Some of the help provided here would have been much easier if I had a bench PSU, both for me and to those using their time to teach me.

    So the question is, what bench PSU do you recommend for a beginner and why? I mostly work on laptop boards and occasionally on TV boards.

    Thanks

    #2
    Re: Bench PSU - Your Suggestions

    What is the highest voltage do you think you might need
    9 PC LCD Monitor
    6 LCD Flat Screen TV
    30 Desk Top Switching Power Supply
    10 Battery Charger Switching Power Supply for Power Tool
    6 18v Lithium Battery Power Boards for Tool Battery Packs
    1 XBox 360 Switching Power Supply and M Board
    25 Servo Drives 220/460 3 Phase
    6 De-soldering Station Switching Power Supply 1 Power Supply
    1 Dell Mother Board
    15 Computer Power Supply
    1 HP Printer Supply & Control Board * lighting finished it *


    These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

    1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
    2 Hem Saw Computer Stack Board

    All of these had CAPs POOF
    All of the mosfet that are taken out by bad caps

    Comment


      #3
      Re: Bench PSU - Your Suggestions

      For laptops I would say 20V max. No idea for TVs, I suspect that would be more.

      Originally posted by sam_sam_sam View Post
      What is the highest voltage do you think you might need

      Comment


        #4
        Re: Bench PSU - Your Suggestions

        H I have two and they are both very useful

        You want variable voltage out and variable current limit

        Many of them are 0-30V 0-5A and I find that enough for most jobs

        I have one same as this though and mine is 5 Amp. When I buy another (never can have enough of these things lol) I would get a 10 amp one. I can only think of one occasion I needed more than 30V

        https://www.ebay.co.uk/itm/DC-30V-10...FydZGXCb6x_gXg

        The other one I have is looks exactly like this one which is a switching supply but mine is slightly lower rated dual 0-30V 3A plus 5V 3A and is a linear supply
        https://www.ebay.co.uk/itm/Rapid-HY3...cAAOSwGF5eFXxh

        I got mine second hand from an amateur radio rally a few years back for 65 GBP in the UK

        I use that more than the other one. It is dual 0-30V 0-3A but you can set it to use both supplies in series or parallel or independent so you can have 0-30V 6A (parallel) or 0-60V 3A (series). Also it an do +0-30V 0V -0-30V for dual rail plus/minus supply

        In additional is has a third fixed 5V Supply.

        The ability of being able to do split rail plus-0-minus supply or having three independant supplies (two 0-30V variable and one fixed 5V) has proved indispensable for repair work. I do mostly TV/Monitor, motherboards and some amplifiers. If you can find one like this second hand for a decent price buy it.

        Rich
        Last edited by dicky96; 03-18-2020, 11:06 AM. Reason: more info
        Follow me on YouTube
        ------------------
        Learn Electronics Repair
        https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

        Comment


          #5
          Re: Bench PSU - Your Suggestions

          The second one is a little bit out of my budget, especially since I'm still a beginner.

          The first one, price wise, is OK. However, I noticed it's unbranded Is that OK?

          Comment


            #6
            Re: Bench PSU - Your Suggestions

            These https://www.ebay.co.uk/itm/HANMATEK-...-/274269251145 are good for the price

            Comment


              #7
              Re: Bench PSU - Your Suggestions

              Originally posted by DanFen View Post
              The second one is a little bit out of my budget, especially since I'm still a beginner.

              The first one, price wise, is OK. However, I noticed it's unbranded Is that OK?
              Those same PSU sometimes have differing brand names on them but I think they are all made in the same factory. I've had mine about three years and it's been fine. Pay with paypal and you can buy with confidence

              The other dual supply I found one second hand for 65 pounds I think it was. Had it about 5 years and no issues with it. Look around for a used one maybe.
              Follow me on YouTube
              ------------------
              Learn Electronics Repair
              https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

              Comment


                #8
                Re: Bench PSU - Your Suggestions

                I got one of those triple psus. I don't know the oem but this one is branded uni-t, and it's been very reliable over the years. A bit bulky but hey it's linear. I've heard newer smps aren't as good for finding dead shorts, because they will go into auto-protect mode.

                Comment


                  #9
                  Re: Bench PSU - Your Suggestions

                  Uni-Trend make their own stuff - it's not rebranded.

                  Comment


                    #10
                    Re: Bench PSU - Your Suggestions

                    Good to know.

                    Comment


                      #11
                      Re: Bench PSU - Your Suggestions

                      Originally posted by paulo66 View Post
                      I've heard newer smps aren't as good for finding dead shorts, because they will go into auto-protect mode.
                      That depends on how well the bench switching power supply are made because I have one and what I do not like about it is that for some reason it always shows a 170 milliamperes load no matter what but it does not seem to affect the use of it and I short circuit it by putting the output leads together at full 10 amps the output shows 10 amps and very little voltage

                      But I have to agree with you that to me the linear bench power supply are better in being able torcher them to hell and back because I have done it and only one time I messed up one of my bench power supply by testing a ignition coil and trying to get it to spark an fried the over voltage diode that I had to replace and the two LED indicator light for the voltage and current the one for the voltage was already having issues anyway after replacing those items everything worked correctly on this bench power supply
                      Last edited by sam_sam_sam; 02-18-2021, 11:07 AM.
                      9 PC LCD Monitor
                      6 LCD Flat Screen TV
                      30 Desk Top Switching Power Supply
                      10 Battery Charger Switching Power Supply for Power Tool
                      6 18v Lithium Battery Power Boards for Tool Battery Packs
                      1 XBox 360 Switching Power Supply and M Board
                      25 Servo Drives 220/460 3 Phase
                      6 De-soldering Station Switching Power Supply 1 Power Supply
                      1 Dell Mother Board
                      15 Computer Power Supply
                      1 HP Printer Supply & Control Board * lighting finished it *


                      These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                      1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                      2 Hem Saw Computer Stack Board

                      All of these had CAPs POOF
                      All of the mosfet that are taken out by bad caps

                      Comment


                        #12
                        Re: Bench PSU - Your Suggestions

                        Interesting. Was the unit out of calibration, or were the minimum 170mA by design?

                        I was thinking about trading my uni-t for an smps if it could deal with dead shorts, it looks the uni-t is worth more than what I had thought. Mine is the utp3704s model. The red one.
                        Attached Files

                        Comment


                          #13
                          Re: Bench PSU - Your Suggestions

                          I think it's better built than another one branded Circuit Specialists. Whether that is OEM´d or a ripoff is anyone´s guess. The Uni-T´s entire backpanel is a heatsink vs. the CS´s two fans. So it´s also quiet as a mouse. Compare that to https://www.ebay.co.uk/p/1342932699 . Scroll for the review with pictures of its innards.

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