Skip to content
  • MySensors
  • OpenHardware.io
  • Categories
  • Recent
  • Tags
  • Popular
Skins
  • Light
  • Brite
  • Cerulean
  • Cosmo
  • Flatly
  • Journal
  • Litera
  • Lumen
  • Lux
  • Materia
  • Minty
  • Morph
  • Pulse
  • Sandstone
  • Simplex
  • Sketchy
  • Spacelab
  • United
  • Yeti
  • Zephyr
  • Dark
  • Cyborg
  • Darkly
  • Quartz
  • Slate
  • Solar
  • Superhero
  • Vapor

  • Default (No Skin)
  • No Skin
Collapse
Brand Logo
  1. Home
  2. Hardware
  3. Safe In-Wall AC to DC Transformers??

Safe In-Wall AC to DC Transformers??

Scheduled Pinned Locked Moved Hardware
431 Posts 71 Posters 557.2k Views 69 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • P Offline
    P Offline
    petewill
    Admin
    wrote on last edited by
    #225

    @rvendrame said:

    @petewill . the MOV goes in parallel with HLK input (and not in series like you did).

    It was suggested to use .2A fuses (instead the .75A). And the Thermal fuse should be glued on HLK top (my guess).

    Dang, totally forgot about all that in my rush to finish the diagram before lunch ended... That's why you guys design the electronics and I make the videos ;)

    How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?

    Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?
    http://www.ebay.com/itm/5-x-Zinc-Oxide-Varistor-150VAC-15J-1200A-7mm-FREE-SHIPPING-/321024816822?hash=item4abe91f6b6

    How does this look?
    HLK-PM01 Wiring.png

    My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA

    S 2 Replies Last reply
    0
    • P petewill

      @rvendrame said:

      @petewill . the MOV goes in parallel with HLK input (and not in series like you did).

      It was suggested to use .2A fuses (instead the .75A). And the Thermal fuse should be glued on HLK top (my guess).

      Dang, totally forgot about all that in my rush to finish the diagram before lunch ended... That's why you guys design the electronics and I make the videos ;)

      How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?

      Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?
      http://www.ebay.com/itm/5-x-Zinc-Oxide-Varistor-150VAC-15J-1200A-7mm-FREE-SHIPPING-/321024816822?hash=item4abe91f6b6

      How does this look?
      HLK-PM01 Wiring.png

      S Offline
      S Offline
      Sparkman
      Hero Member
      wrote on last edited by Sparkman
      #226

      @petewill said:

      Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?

      As long as you only feed it with 120VAC, there's no issue with that. For those that will feed it with 240VAC, they need to use it with a MOV rated above that.

      Cheers
      Al

      PS Here's an option from Digikey: http://www.digikey.com/product-detail/en/MOV-10D241K/MOV-10D241K-ND/2407562

      1 Reply Last reply
      0
      • P petewill

        @rvendrame said:

        @petewill . the MOV goes in parallel with HLK input (and not in series like you did).

        It was suggested to use .2A fuses (instead the .75A). And the Thermal fuse should be glued on HLK top (my guess).

        Dang, totally forgot about all that in my rush to finish the diagram before lunch ended... That's why you guys design the electronics and I make the videos ;)

        How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?

        Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?
        http://www.ebay.com/itm/5-x-Zinc-Oxide-Varistor-150VAC-15J-1200A-7mm-FREE-SHIPPING-/321024816822?hash=item4abe91f6b6

        How does this look?
        HLK-PM01 Wiring.png

        S Offline
        S Offline
        Sparkman
        Hero Member
        wrote on last edited by Sparkman
        #227

        @petewill said:

        How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?

        The fuse serves two purposes, one to protect if the current draw of the power supply exceeds its rated capacity and the other to blow if the varistor starts conducting a large amount of current in a spike situation. A .75A will still provide protection, but will take a longer time to blow. You want to make sure the fuse doesn't blow because of the in-rush current at start-up, which a fast-blow fuse may do. Typically you want the fuse to be sized at about 150% max of the rated capacity so I would not exceed .3A.

        Cheers
        Al

        P 1 Reply Last reply
        0
        • S Sparkman

          @petewill said:

          How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?

          The fuse serves two purposes, one to protect if the current draw of the power supply exceeds its rated capacity and the other to blow if the varistor starts conducting a large amount of current in a spike situation. A .75A will still provide protection, but will take a longer time to blow. You want to make sure the fuse doesn't blow because of the in-rush current at start-up, which a fast-blow fuse may do. Typically you want the fuse to be sized at about 150% max of the rated capacity so I would not exceed .3A.

          Cheers
          Al

          P Offline
          P Offline
          petewill
          Admin
          wrote on last edited by
          #228

          @Sparkman

          As long as you only feed it with 120VAC, there's no issue with that. For those that will feed it with 240VAC, they need to use it with a MOV rated above that.

          I am in the USA so I will only be feeding it with 120VAC, but I will make sure to note that anyone using 240VAC will need a different value varistor.

          the fuse should be after the varistor in the circuit

          Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.

          Also, I found some fuses that are rated at 300mA! Not a bad price either!
          http://www.ebay.com/itm/Ceramic-Slow-Blow-Fuse-3-6-x-10mm-Axial-Leads-125V-250V-0-1A-6-3A-10-30pcs-/111433875797?var=&hash=item19f1fa0155

          I think I am almost ready to start ordering parts. I am excited for this build! If anyone else has any feedback please let me know. Thanks!

          My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA

          S 1 Reply Last reply
          0
          • P petewill

            @Sparkman

            As long as you only feed it with 120VAC, there's no issue with that. For those that will feed it with 240VAC, they need to use it with a MOV rated above that.

            I am in the USA so I will only be feeding it with 120VAC, but I will make sure to note that anyone using 240VAC will need a different value varistor.

            the fuse should be after the varistor in the circuit

            Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.

            Also, I found some fuses that are rated at 300mA! Not a bad price either!
            http://www.ebay.com/itm/Ceramic-Slow-Blow-Fuse-3-6-x-10mm-Axial-Leads-125V-250V-0-1A-6-3A-10-30pcs-/111433875797?var=&hash=item19f1fa0155

            I think I am almost ready to start ordering parts. I am excited for this build! If anyone else has any feedback please let me know. Thanks!

            S Offline
            S Offline
            Sparkman
            Hero Member
            wrote on last edited by
            #229

            @petewill said:

            @Sparkman

            the fuse should be after the varistor in the circuit

            Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.

            Sorry, the wording I used was unclear and was based on the 120VAC being on the right in your diagram :-). Yes, it is 120VAC -> Fuse -> Varistor -> HLK.

            Cheers
            Al

            P 1 Reply Last reply
            0
            • S Sparkman

              @petewill said:

              @Sparkman

              the fuse should be after the varistor in the circuit

              Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.

              Sorry, the wording I used was unclear and was based on the 120VAC being on the right in your diagram :-). Yes, it is 120VAC -> Fuse -> Varistor -> HLK.

              Cheers
              Al

              P Offline
              P Offline
              petewill
              Admin
              wrote on last edited by
              #230

              @Sparkman Great, thanks! The parts have been ordered. Can't wait!

              My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA

              1 Reply Last reply
              0
              • C ceech

                This one is not "safe", but it is an In-Wall AC to DC converter. Transformerless. With a 3A Solid state relay:

                2015-08-21T12-11-1.jpg

                2015-08.jpg

                The converter output is 3.3V at 100mA and the solid state relay is a Triac.

                F Offline
                F Offline
                Fabien
                wrote on last edited by
                #231

                @ceech said:

                This one is not "safe", but it is an In-Wall AC to DC converter. Transformerless. With a 3A Solid state relay:

                2015-08-21T12-11-1.jpg

                2015-08.jpg

                The converter output is 3.3V at 100mA and the solid state relay is a Triac.

                Do you have some shcematic of this board ? I'd like to adapt it for 2 relays

                C 1 Reply Last reply
                0
                • Cliff KarlssonC Offline
                  Cliff KarlssonC Offline
                  Cliff Karlsson
                  wrote on last edited by
                  #232

                  Can anyone give me ebay-links to the parts I need to order to use the HLK with 230V.

                  I am getting a little confused about all the links.

                  1 Reply Last reply
                  0
                  • R Offline
                    R Offline
                    rvendrame
                    Hero Member
                    wrote on last edited by rvendrame
                    #233

                    This is the one I sent to be reviewed:

                    http://www.aliexpress.com/item/Free-Shipping-1pcs-lot-HLK-PM01-AC-DC-220V-to-5V-mini-power-supply-module-intelligent/32408565688.html

                    Home Assistant / Vera Plus UI7
                    ESP8266 GW + mySensors 2.3.2
                    Alexa / Google Home

                    1 Reply Last reply
                    0
                    • Cliff KarlssonC Offline
                      Cliff KarlssonC Offline
                      Cliff Karlsson
                      wrote on last edited by
                      #234

                      Ok thanks, but I meant the fuses, varistors and stuff.

                      P 1 Reply Last reply
                      0
                      • Cliff KarlssonC Cliff Karlsson

                        Ok thanks, but I meant the fuses, varistors and stuff.

                        P Offline
                        P Offline
                        petewill
                        Admin
                        wrote on last edited by
                        #235

                        @Cliff-Karlsson
                        I haven't tested any of these parts yet but this is what I ordered. I am in the USA so this is spec'd for 120 VAC. If you're using 240 you will need to change the size of the Varistor but everything else should be fine for 240.

                        Varistor for 120VAC - http://www.ebay.com/itm/321024816822?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

                        73°C Thermal Fuse - http://www.ebay.com/itm/221560426284?_trksid=p2057872.m2749.l2649&var=520415979885&ssPageName=STRK%3AMEBIDX%3AIT

                        250V 300mA Slow Blow Fuse - http://www.ebay.com/itm/111433875797?_trksid=p2057872.m2749.l2649&var=410420838583&ssPageName=STRK%3AMEBIDX%3AIT

                        HLK-PM01 - http://www.ebay.com/itm/351418782712?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

                        My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA

                        1 Reply Last reply
                        1
                        • F Fabien

                          @ceech said:

                          This one is not "safe", but it is an In-Wall AC to DC converter. Transformerless. With a 3A Solid state relay:

                          2015-08-21T12-11-1.jpg

                          2015-08.jpg

                          The converter output is 3.3V at 100mA and the solid state relay is a Triac.

                          Do you have some shcematic of this board ? I'd like to adapt it for 2 relays

                          C Offline
                          C Offline
                          ceech
                          Hardware Contributor
                          wrote on last edited by
                          #236

                          @Fabien @DrJeff Here is a link to board and schematic files for the transformerless AC-DC converter:
                          https://github.com/ceech/AC_SR087

                          DrJeffD 1 Reply Last reply
                          2
                          • M Offline
                            M Offline
                            MartinP
                            wrote on last edited by
                            #237

                            Would this varistor work with 240v?
                            http://www.ebay.com/itm/10-x-Zinc-Oxide-Varistor-250VAC-60J-2500A-10mm-/260848704608?hash=item3cbbcb5c60

                            P 1 Reply Last reply
                            0
                            • C ceech

                              @Fabien @DrJeff Here is a link to board and schematic files for the transformerless AC-DC converter:
                              https://github.com/ceech/AC_SR087

                              DrJeffD Offline
                              DrJeffD Offline
                              DrJeff
                              wrote on last edited by
                              #238

                              @ceech can't look at the files right now is this a dimmer switch that is transformerless?

                              C 1 Reply Last reply
                              0
                              • DrJeffD DrJeff

                                @ceech can't look at the files right now is this a dimmer switch that is transformerless?

                                C Offline
                                C Offline
                                ceech
                                Hardware Contributor
                                wrote on last edited by
                                #239

                                @DrJeff Yes

                                DrJeffD 1 Reply Last reply
                                0
                                • C ceech

                                  @DrJeff Yes

                                  DrJeffD Offline
                                  DrJeffD Offline
                                  DrJeff
                                  wrote on last edited by
                                  #240

                                  @ceech Thanks yet again!

                                  1 Reply Last reply
                                  0
                                  • M MartinP

                                    Would this varistor work with 240v?
                                    http://www.ebay.com/itm/10-x-Zinc-Oxide-Varistor-250VAC-60J-2500A-10mm-/260848704608?hash=item3cbbcb5c60

                                    P Offline
                                    P Offline
                                    petewill
                                    Admin
                                    wrote on last edited by
                                    #241

                                    @MartinP Based on my limited knowledge, yes, that should work. Maybe someone else can chime in to confirm?

                                    My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA

                                    S 1 Reply Last reply
                                    0
                                    • F Offline
                                      F Offline
                                      Fabien
                                      wrote on last edited by
                                      #242

                                      thank you @ceech

                                      1 Reply Last reply
                                      0
                                      • P petewill

                                        @MartinP Based on my limited knowledge, yes, that should work. Maybe someone else can chime in to confirm?

                                        S Offline
                                        S Offline
                                        Sparkman
                                        Hero Member
                                        wrote on last edited by
                                        #243

                                        @petewill said:

                                        @MartinP Based on my limited knowledge, yes, that should work. Maybe someone else can chime in to confirm?

                                        I would personally go with a higher voltage rating. Something like 15-20% higher than your normal voltage otherwise you may get regular nuisance trips. So for a 240 VAC system, I would use something close to 290V.

                                        Cheers
                                        Al

                                        P 1 Reply Last reply
                                        0
                                        • S Sparkman

                                          @petewill said:

                                          @MartinP Based on my limited knowledge, yes, that should work. Maybe someone else can chime in to confirm?

                                          I would personally go with a higher voltage rating. Something like 15-20% higher than your normal voltage otherwise you may get regular nuisance trips. So for a 240 VAC system, I would use something close to 290V.

                                          Cheers
                                          Al

                                          P Offline
                                          P Offline
                                          petewill
                                          Admin
                                          wrote on last edited by
                                          #244

                                          @Sparkman Thanks!

                                          My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA

                                          1 Reply Last reply
                                          0

                                          Hello! It looks like you're interested in this conversation, but you don't have an account yet.

                                          Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.

                                          With your input, this post could be even better 💗

                                          Register Login
                                          Reply
                                          • Reply as topic
                                          Log in to reply
                                          • Oldest to Newest
                                          • Newest to Oldest
                                          • Most Votes


                                          18

                                          Online

                                          12.0k

                                          Users

                                          11.2k

                                          Topics

                                          113.4k

                                          Posts


                                          Copyright 2025 TBD   |   Forum Guidelines   |   Privacy Policy   |   Terms of Service
                                          • Login

                                          • Don't have an account? Register

                                          • Login or register to search.
                                          • First post
                                            Last post
                                          0
                                          • MySensors
                                          • OpenHardware.io
                                          • Categories
                                          • Recent
                                          • Tags
                                          • Popular