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Power supply build quality pictorial. part 2

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    Re: Power supply build quality pictorial. part 2

    Originally posted by ben7 View Post
    Scenic:
    Haha, thats a good looking supply!, although it could use a bigger heatsink on the regulator.
    That's probably the reason why it's labelled as 1amp max., despite the LM317T being able to deliver 1.5amps.

    edit: forgot to mention.. mine has 4 diodes hidden behind the heatsink
    Last edited by Scenic; 12-04-2011, 03:59 PM.

    Comment


      Re: Power supply build quality pictorial. part 2

      Originally posted by ben7 View Post
      Oh silly, the black round thing is a bridge rectifier

      -Ben
      Why does it have a diode on the rear side too then?
      "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
      -David VanHorn

      Comment


        Re: Power supply build quality pictorial. part 2

        You're right - I opened it up again and it has 4 legs.. so it's the rectifier. I initially counted only 3 legs, that's why I assumed it's a transistor.
        Now I'm not so sure about the point of the IN4001 diode on the other side connecting two of the legs of the rectifier...

        Yeah... I don't think the transformer is able to do more than 200-300mA....

        Comment


          Re: Power supply build quality pictorial. part 2

          Originally posted by ben7 View Post
          Infact, i could go to the surplus store and get a whole bag of phone chargers for a few bucks, would be interesting to dissect them.

          The Best phone charger I have seen was an old nokia charger, it had an Astec power supply, with Lelon and Nichicon caps in it, a nicely sized transistor, a control chip, secondary feedback, and even a mini bridge rectifier on the input!

          -Ben
          Here it is!

          Notice that there are no Nichicons here... Only Lelon and Ltec and some are 85C.
          Attached Files

          Comment


            Re: Power supply build quality pictorial. part 2

            Originally posted by goodpsusearch View Post
            Here it is!

            Notice that there are no Nichicons here... Only Lelon and Ltec and some are 85C.
            Heh, is it me or are the primary caps slightly bulged?

            -Ben

            Edit: the one I took apart must have been a different version, it has a defferent layout, etc.. may be able to post a pic or two tomorrow!
            Muh-soggy-knee

            Comment


              Re: Power supply build quality pictorial. part 2

              Originally posted by Scenic View Post
              Reminded me of my universal wallwart that i bought when i was 9 or 10 (I'm 24 now).
              Except mine does what the label says and i't considerably more beefy than that black blob of plastic and metal that wants to be a PSU in your pics lol

              AAA battery for size comparison.
              There's a SEC (Samsung) LM317T on that heatsink (capable of 1.5A, so the PSU is underrated by 500mA)
              Used to have one just like that. Not sure of its current whereabouts tho.
              Originally posted by PeteS in CA
              Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
              A working TV? How boring!

              Comment


                Re: Power supply build quality pictorial. part 2

                Originally posted by ben7 View Post
                Heh, is it me or are the primary caps slightly bulged?

                -Ben

                Edit: the one I took apart must have been a different version, it has a defferent layout, etc.. may be able to post a pic or two tomorrow!
                No, it's due to the macro and the flash

                This is the cheapest nokia charger available. It takes forever to charge big capacity batteries!

                Comment


                  Re: Power supply build quality pictorial. part 2

                  I had a Nokia ACP-12E (E for europe) made by Astec. Had a break in the cable somewhere.
                  Caps were Nichicon and Elna.
                  5.7V 800mA output

                  The Salcomp (Finland) made ACP-8E had Elna everywhere.
                  5.3V 500mA output
                  Most newer ones use LTec and Lelon exclusively.. bye bye quality..

                  Comment


                    Re: Power supply build quality pictorial. part 2

                    Btw the one in the photo had a break in the cable too and that's the reason I opened it.

                    Comment


                      Re: Power supply build quality pictorial. part 2

                      Here is another wall wart. This is the power supply that came with the Harman Kardon HK-206 speakers I recapped. The filter cap is a Fulltec RHA 2200uF 25V (possibly low ESR) and the diodes are RL201s. Note that there is no thermal cutoff on the transformer and the transformer and circuit board just flop around inside the case when the back cover is removed.
                      Attached Files

                      Comment


                        Re: Power supply build quality pictorial. part 2

                        Originally posted by mariushm View Post
                        You're right - I opened it up again and it has 4 legs.. so it's the rectifier. I initially counted only 3 legs, that's why I assumed it's a transistor.
                        Now I'm not so sure about the point of the IN4001 diode on the other side connecting two of the legs of the rectifier...
                        Probably because the bridge rectifier has an open diode (or shorted, but they "fixed" that with a short burst of high current ) so it's cheaper to add another diode around it.

                        Notice the current through the LED changes with the voltage selector switch position
                        Attached Files

                        Comment


                          Re: Power supply build quality pictorial. part 2

                          Originally posted by b700029 View Post
                          Probably because the bridge rectifier has an open diode (or shorted, but they "fixed" that with a short burst of high current ) so it's cheaper to add another diode around it.

                          Notice the current through the LED changes with the voltage selector switch position
                          Ok, I also think there was a bit of confusion there, I cant see any extra diode on the circut board, just the bridge rectifier, LED, resistor, and capacitor( & switches).

                          -Ben
                          Muh-soggy-knee

                          Comment


                            Re: Power supply build quality pictorial. part 2

                            Originally posted by ben7 View Post
                            Ok, I also think there was a bit of confusion there, I cant see any extra diode on the circut board, just the bridge rectifier, LED, resistor, and capacitor( & switches).

                            -Ben
                            Check his 2nd photo where it shows the back side of the board.
                            "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                            -David VanHorn

                            Comment


                              Re: Power supply build quality pictorial. part 2

                              Originally posted by Agent24 View Post
                              Check his 2nd photo where it shows the back side of the board.
                              Haha, getting myself all confused! Yes, there is a diode there!


                              But its in a very strange setup :S

                              -Ben

                              EDIT:
                              HAHA WTF! the circuit b700029 drew is correct too, they added an extra diode for some reason.

                              I am surprised that they will do stuff like this to save money! :O
                              Last edited by ben7; 12-05-2011, 06:24 PM.
                              Muh-soggy-knee

                              Comment


                                Re: Power supply build quality pictorial. part 2

                                For the quality of the rest of the thing, I'm surprised it's even got a full-wave rectifier!
                                "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                                -David VanHorn

                                Comment


                                  Re: Power supply build quality pictorial. part 2

                                  Originally posted by Agent24 View Post
                                  For the quality of the rest of the thing, I'm surprised it's even got a full-wave rectifier!
                                  Haha, yeah, some just use one diode

                                  -Ben
                                  Muh-soggy-knee

                                  Comment


                                    Re: Power supply build quality pictorial. part 2

                                    I had to take a look inside these "replacement" chargers for some Hp laptops... This one is probalby the cheapest out there. I expected much worse.
                                    Attached Files

                                    Comment


                                      Re: Power supply build quality pictorial. part 2

                                      Originally posted by goodpsusearch View Post
                                      Here it is!

                                      Notice that there are no Nichicons here... Only Lelon and Ltec and some are 85C.
                                      Has Astec gone downhill? They used to have good caps in their power supplies...
                                      My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

                                      Comment


                                        Re: Power supply build quality pictorial. part 2

                                        Originally posted by semenov_av View Post
                                        which transistors are on the reverse side pa-3241-02a ?
                                        Did you find out the issue about the transisors? I've got the same question.
                                        Alex

                                        Comment


                                          Re: Power supply build quality pictorial. part 2

                                          I found this guys channel on YT, I also love the teardown videos he does!

                                          check out his latest video, he does a teardown of an el-cheapo 'smps' power supply...

                                          -Ben
                                          Muh-soggy-knee

                                          Comment

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