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  3. Safe In-Wall AC to DC Transformers??

Safe In-Wall AC to DC Transformers??

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  • B Bertb

    @petewill The schematic is just a simple draft. It can be seen with IE.

    Moshe LivneM Offline
    Moshe LivneM Offline
    Moshe Livne
    Hero Member
    wrote on last edited by
    #151

    @Bertb I tried adding "html" suffix to it but it didn't work.

    1 Reply Last reply
    0
    • A Offline
      A Offline
      aproxx
      Hero Member
      wrote on last edited by
      #152

      One option is to click on the link and download the file. After the file is completely downloaded, just add the extention .jpg to it.

      The result is as following:
      1438251516188-draft-schematic.jpg

      1 Reply Last reply
      0
      • B Offline
        B Offline
        Bertb
        wrote on last edited by
        #153

        Something went wrong with uploading the file, I think.
        Herewith a new schematic with a suggested bill of material.
        It is highly experimental still, but I ordered the components yesterday.

        I am specially interested in working with the PTC fuse.

        I hope the proposed circuit works for you. Please keep the maximim continuous output power in mind. It is only 3 Watts (600 mA).
        In some cases you might need to add C1's (rule of thump 1 per chip or chip VCC) and/or need to increase the value of C2. This depends on the fluctuations in the power demand.

        With the proposed values for C1 and C2, the ripple remained below 50 mV at 500 mA.
        Also keep in mind that a remaining oscillation frequency residue appears in the output of some 60kHz.. If capacitors are not able to filter that out, a small coil might be needed.

        Well it is experimenting that makes this fun, isn't it?

        Draft schematic2.jpg

        Moshe LivneM 1 Reply Last reply
        0
        • rvendrameR rvendrame

          Hey guys, I wrote to the owner of the site suggested by @Moshe-Livne. He replied saying that he can test the HLK.

          He mentioned that usually he takes at least two units (so if one burn he can continue the testing). I will send one from my lot, perhaps we have a brave guy to gave up one more? (a sacrifice of few to save many ) ;-) Let me know and I will share the address via PM (Denmark).

          B Offline
          B Offline
          Bertb
          wrote on last edited by
          #154

          @rvendrame said:

          Hey guys, I wrote to the owner of the site suggested by @Moshe-Livne. He replied saying that he can test the HLK.

          He mentioned that usually he takes at least two units (so if one burn he can continue the testing). I will send one from my lot, perhaps we have a brave guy to gave up one more? (a sacrifice of few to save many ) ;-) Let me know and I will share the address via PM (Denmark).

          I am in for this.

          1 Reply Last reply
          0
          • rvendrameR rvendrame

            Hey guys, I wrote to the owner of the site suggested by @Moshe-Livne. He replied saying that he can test the HLK.

            He mentioned that usually he takes at least two units (so if one burn he can continue the testing). I will send one from my lot, perhaps we have a brave guy to gave up one more? (a sacrifice of few to save many ) ;-) Let me know and I will share the address via PM (Denmark).

            DidiD Offline
            DidiD Offline
            Didi
            wrote on last edited by
            #155

            @rvendrame said:

            Let me know and I will share the address via PM (Denmark).

            I will send him a powersupply too. :stuck_out_tongue_winking_eye:

            if (knowledge == 0) { use BRAIN; use GOOGLE;use SEARCH; } else {make POST;}

            1 Reply Last reply
            0
            • B Bertb

              Something went wrong with uploading the file, I think.
              Herewith a new schematic with a suggested bill of material.
              It is highly experimental still, but I ordered the components yesterday.

              I am specially interested in working with the PTC fuse.

              I hope the proposed circuit works for you. Please keep the maximim continuous output power in mind. It is only 3 Watts (600 mA).
              In some cases you might need to add C1's (rule of thump 1 per chip or chip VCC) and/or need to increase the value of C2. This depends on the fluctuations in the power demand.

              With the proposed values for C1 and C2, the ripple remained below 50 mV at 500 mA.
              Also keep in mind that a remaining oscillation frequency residue appears in the output of some 60kHz.. If capacitors are not able to filter that out, a small coil might be needed.

              Well it is experimenting that makes this fun, isn't it?

              Draft schematic2.jpg

              Moshe LivneM Offline
              Moshe LivneM Offline
              Moshe Livne
              Hero Member
              wrote on last edited by
              #156

              @Bertb can now see the scheme! thanks. But can't see the BOM

              1 Reply Last reply
              0
              • B Offline
                B Offline
                Bertb
                wrote on last edited by
                #157

                ... it must be friday ...

                voeding.doc

                DidiD 1 Reply Last reply
                0
                • B Bertb

                  ... it must be friday ...

                  voeding.doc

                  DidiD Offline
                  DidiD Offline
                  Didi
                  wrote on last edited by
                  #158

                  @Bertb said:

                  voeding.doc

                  can you make a pdf, i have no microsoft office

                  if (knowledge == 0) { use BRAIN; use GOOGLE;use SEARCH; } else {make POST;}

                  1 Reply Last reply
                  0
                  • B Offline
                    B Offline
                    Bertb
                    wrote on last edited by
                    #159

                    As you please ...

                    voeding.pdf

                    DidiD 1 Reply Last reply
                    2
                    • B Bertb

                      As you please ...

                      voeding.pdf

                      DidiD Offline
                      DidiD Offline
                      Didi
                      wrote on last edited by
                      #160

                      @Bertb said:

                      As you please ...

                      thank you

                      if (knowledge == 0) { use BRAIN; use GOOGLE;use SEARCH; } else {make POST;}

                      1 Reply Last reply
                      0
                      • B Offline
                        B Offline
                        Bertb
                        wrote on last edited by
                        #161

                        I managed to borrow a Megger (high voltage resistance measurement device). This weekend I will test the insulation of the MLK.
                        The only drawback is that the Megger reaches to 1000 Volt.

                        1 Reply Last reply
                        0
                        • rvendrameR Offline
                          rvendrameR Offline
                          rvendrame
                          Hero Member
                          wrote on last edited by
                          #162

                          @Moshe-Livne said:

                          @rvendrame Considering cost of postage and logistics involved it would probably be cheapest to just order two units from Ali to him? its 8$ including shipping if i remember correctly

                          Yes, it makes all sense. The only downside is that if we buy all at same time probably he will get all from the same lot, but in my opinion it by far doesn't invalidate the testing.

                          So, myself, @Bertb , @Didi = 3 PSUs, better than 2. I will share with you both the ship-to address ok? Thanks a lot!

                          Home Assistant / Vera Plus UI7
                          ESP8266 GW + mySensors 2.3.2
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                          B 1 Reply Last reply
                          0
                          • DidiD Offline
                            DidiD Offline
                            Didi
                            wrote on last edited by
                            #163

                            @rvendrame said:

                            So, myself, @Bertb , @Didi = 3 PSUs, better than 2. I will share with you both the ship-to address ok? Thanks a lot!

                            :thumbsup:

                            if (knowledge == 0) { use BRAIN; use GOOGLE;use SEARCH; } else {make POST;}

                            1 Reply Last reply
                            0
                            • A Offline
                              A Offline
                              aproxx
                              Hero Member
                              wrote on last edited by aproxx
                              #164

                              I'm really happy to hear that these HLK power modules are considered to be safe. I've been using them for a few weeks already, but didn't have a clue what was inside (and whether they were ACTUALLY safe).

                              One question regarding the varistor and PTC fuses though:
                              Any reason (or specifications) why you chose those specific components? I've been looking for myself as well, but came up with slightly different components.

                              Fuse1 and 2: PTC Resettable Fuses 250V 1A TRF250-1000

                              Varistor1: [10D391K 10K391 390V varistor diameter 10mm AC 250V DC 320V]
                              (http://www.aliexpress.com/item/Varistor-10D391K-10D-391K-VDR-10K391-Metal-voltage-dependent-resistor-50pcs-bag/1912418587.html)

                              Varistor2: [5.5V Varistor original Varistor resistor]
                              (http://www.aliexpress.com/item/SMD-1206-5-5V-Varistor-original-Varistor-resistor-100pcs-lot/32243046238.html)

                              If anyone with a bit more experience could have some feedback on these components, that would be really really appreciated!!

                              B 1 Reply Last reply
                              1
                              • rvendrameR rvendrame

                                @Moshe-Livne said:

                                @rvendrame Considering cost of postage and logistics involved it would probably be cheapest to just order two units from Ali to him? its 8$ including shipping if i remember correctly

                                Yes, it makes all sense. The only downside is that if we buy all at same time probably he will get all from the same lot, but in my opinion it by far doesn't invalidate the testing.

                                So, myself, @Bertb , @Didi = 3 PSUs, better than 2. I will share with you both the ship-to address ok? Thanks a lot!

                                B Offline
                                B Offline
                                Bertb
                                wrote on last edited by
                                #165

                                @rvendrame said:

                                @Moshe-Livne said:

                                @rvendrame Considering cost of postage and logistics involved it would probably be cheapest to just order two units from Ali to him? its 8$ including shipping if i remember correctly

                                Yes, it makes all sense. The only downside is that if we buy all at same time probably he will get all from the same lot, but in my opinion it by far doesn't invalidate the testing.

                                So, myself, @Bertb , @Didi = 3 PSUs, better than 2. I will share with you both the ship-to address ok? Thanks a lot!

                                :+1:

                                1 Reply Last reply
                                0
                                • A aproxx

                                  I'm really happy to hear that these HLK power modules are considered to be safe. I've been using them for a few weeks already, but didn't have a clue what was inside (and whether they were ACTUALLY safe).

                                  One question regarding the varistor and PTC fuses though:
                                  Any reason (or specifications) why you chose those specific components? I've been looking for myself as well, but came up with slightly different components.

                                  Fuse1 and 2: PTC Resettable Fuses 250V 1A TRF250-1000

                                  Varistor1: [10D391K 10K391 390V varistor diameter 10mm AC 250V DC 320V]
                                  (http://www.aliexpress.com/item/Varistor-10D391K-10D-391K-VDR-10K391-Metal-voltage-dependent-resistor-50pcs-bag/1912418587.html)

                                  Varistor2: [5.5V Varistor original Varistor resistor]
                                  (http://www.aliexpress.com/item/SMD-1206-5-5V-Varistor-original-Varistor-resistor-100pcs-lot/32243046238.html)

                                  If anyone with a bit more experience could have some feedback on these components, that would be really really appreciated!!

                                  B Offline
                                  B Offline
                                  Bertb
                                  wrote on last edited by
                                  #166

                                  @aproxx I would say that the 50 mA fuse is too weak. The HLK draws between 0.1 and 0.2 Amp and can surge 10 Amp. So, I think the 1A version is good for both situations input and output. The varistor is only good for the output.
                                  One thing to consider though. This is also chinese stuff ... is it really safe or are we introducing a new problem? :smile:

                                  1 Reply Last reply
                                  0
                                  • A Offline
                                    A Offline
                                    aproxx
                                    Hero Member
                                    wrote on last edited by
                                    #167

                                    @Bertb Aaah yes now I see. It does seem to draw much more peak current than I expected! Then I'll just use the same component as I'm using for Fuse 2.
                                    What do you mean by "The varistor is only good for the output."? You're using one as input and one as output in your diagram as well or am I missing something?

                                    And yes, I know this is Chinese stuff again.. But single (chinese) components never failed on me (until now). :smiley:

                                    B 1 Reply Last reply
                                    0
                                    • A aproxx

                                      @Bertb Aaah yes now I see. It does seem to draw much more peak current than I expected! Then I'll just use the same component as I'm using for Fuse 2.
                                      What do you mean by "The varistor is only good for the output."? You're using one as input and one as output in your diagram as well or am I missing something?

                                      And yes, I know this is Chinese stuff again.. But single (chinese) components never failed on me (until now). :smiley:

                                      B Offline
                                      B Offline
                                      Bertb
                                      wrote on last edited by
                                      #168

                                      @aproxx The only varistor I see in your list is 5.5 Volt.

                                      1 Reply Last reply
                                      0
                                      • A Offline
                                        A Offline
                                        aproxx
                                        Hero Member
                                        wrote on last edited by
                                        #169

                                        @Bertb I see what is getting both of us confused.
                                        Apparently something was wrong in the link of my previous post, resulting in the 2nd varistor not being listed. So now your comment about the varistor only being good for the output makes sense as well. :smiley:
                                        I've fixed the link of my post above!

                                        B 1 Reply Last reply
                                        0
                                        • A aproxx

                                          @Bertb I see what is getting both of us confused.
                                          Apparently something was wrong in the link of my previous post, resulting in the 2nd varistor not being listed. So now your comment about the varistor only being good for the output makes sense as well. :smiley:
                                          I've fixed the link of my post above!

                                          B Offline
                                          B Offline
                                          Bertb
                                          wrote on last edited by
                                          #170

                                          @aproxx This is a different kind of notation, but when I look the device up in de Bourns catalog, I see it is rated for 250 Vac. That should be good.

                                          link text

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