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  3. converting 12v to 5v

converting 12v to 5v

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  • rvendrameR rvendrame

    Maybe if you post the circuit, it will be easy to understand. Anyway, I think the less-invasive method is by using a optocoupler:

    voorbeeld - dragoslav_1.jpg

    Moshe LivneM Offline
    Moshe LivneM Offline
    Moshe Livne
    Hero Member
    wrote on last edited by
    #19

    @rvendrame here is the page from the manual:
    doorbell_20150626_0001.jpg

    my installation is the one without the batteries,
    i'll get some optocouplers and play. Thanks!

    AWIA 1 Reply Last reply
    0
    • Moshe LivneM Moshe Livne

      @rvendrame here is the page from the manual:
      doorbell_20150626_0001.jpg

      my installation is the one without the batteries,
      i'll get some optocouplers and play. Thanks!

      AWIA Offline
      AWIA Offline
      AWI
      Hero Member
      wrote on last edited by
      #20

      @Moshe-Livne Do you have a volt meter? Than measure between 0 and 1 while pressing the button and releasing it (or 0 and 2, depending which one is used) and than post your measurements. From the pictures I imagine that it is a DC circuit.

      Moshe LivneM 2 Replies Last reply
      0
      • AWIA AWI

        @Moshe-Livne Do you have a volt meter? Than measure between 0 and 1 while pressing the button and releasing it (or 0 and 2, depending which one is used) and than post your measurements. From the pictures I imagine that it is a DC circuit.

        Moshe LivneM Offline
        Moshe LivneM Offline
        Moshe Livne
        Hero Member
        wrote on last edited by
        #21

        @rvendrame Oh wow. there are zillions of kinds... As aliexpress are a bit thin on details, anyone knows when one I should get to detect 6v 6ma ?

        1 Reply Last reply
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        • AWIA AWI

          @Moshe-Livne Do you have a volt meter? Than measure between 0 and 1 while pressing the button and releasing it (or 0 and 2, depending which one is used) and than post your measurements. From the pictures I imagine that it is a DC circuit.

          Moshe LivneM Offline
          Moshe LivneM Offline
          Moshe Livne
          Hero Member
          wrote on last edited by
          #22

          @AWI It is 6vdc, about 6ma current. i tried to tap it for powering the arduino but its not enough

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          • rvendrameR rvendrame

            @Moshe-Livne , it should be simpler than that --- Just connect the ground of the doorbell to arduino's ground, and use a voltage divider below to divide the +12v by lets say, 3, and connect it to any arduino input pin.

            R1 = 670K and R2 = 470K should do the trick... 12V will become ~4V , and digitalRead() will read '1' when the bell rings (and zero when idle).

            voltage-divider-w.gif

            AWIA Offline
            AWIA Offline
            AWI
            Hero Member
            wrote on last edited by AWI
            #23

            @Moshe-Livne going back to an earlier suggestion from @rvendrame (adapted a little for the situation)

            Current is not important here as long as you do don't power the arduino from it. Just connect the ground of the doorbell to arduino's ground, and use a voltage divider below in parallel (U1) with the pushbutton. This divides the voltage of +6v by 1.5, and can be connected to any arduino input pin (Digital or Analog).

            R1 = 470K and R2 = 670K should do the trick... 6V (U1) will become ~4V (U2) , and digitalRead() will read 'low' when the bell rings (and 'high' when idle).

            voltage-divider-w.gif

            Moshe LivneM 1 Reply Last reply
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            • AWIA AWI

              @Moshe-Livne going back to an earlier suggestion from @rvendrame (adapted a little for the situation)

              Current is not important here as long as you do don't power the arduino from it. Just connect the ground of the doorbell to arduino's ground, and use a voltage divider below in parallel (U1) with the pushbutton. This divides the voltage of +6v by 1.5, and can be connected to any arduino input pin (Digital or Analog).

              R1 = 470K and R2 = 670K should do the trick... 6V (U1) will become ~4V (U2) , and digitalRead() will read 'low' when the bell rings (and 'high' when idle).

              voltage-divider-w.gif

              Moshe LivneM Offline
              Moshe LivneM Offline
              Moshe Livne
              Hero Member
              wrote on last edited by
              #24

              @AWI Errrr tried something similar before and the bell was ringing continuously as if the arduino acted as a short. might be something stupid i did. I excel in these. maybe defined the pin as output. will double check tomorrow.
              Thanks!

              1 Reply Last reply
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              • tbowmoT Offline
                tbowmoT Offline
                tbowmo
                Admin
                wrote on last edited by tbowmo
                #25

                hmm.. only 6v DC?

                why use optocouplers for that? Could also be done very simple with a resistor and one or two diodes.

                connect gnd together, a 10-100k resistor in line with the +6V signal to the input on arduino, and a clamping diode to VCC (optionally a second clamping diode to GND for good measures).

                See the first answer to the question here http://electronics.stackexchange.com/questions/45127/what-kind-of-diode-to-use-with-adc-inputs

                Moshe LivneM 2 Replies Last reply
                0
                • rvendrameR Offline
                  rvendrameR Offline
                  rvendrame
                  Hero Member
                  wrote on last edited by
                  #26

                  @tbowmo , I suggested the optocoupler as an alternative to not trigger the ring as Moshe Livne had mentioned. But I agree with you, it should work without it if connected in the right way.

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

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                  • tbowmoT tbowmo

                    hmm.. only 6v DC?

                    why use optocouplers for that? Could also be done very simple with a resistor and one or two diodes.

                    connect gnd together, a 10-100k resistor in line with the +6V signal to the input on arduino, and a clamping diode to VCC (optionally a second clamping diode to GND for good measures).

                    See the first answer to the question here http://electronics.stackexchange.com/questions/45127/what-kind-of-diode-to-use-with-adc-inputs

                    Moshe LivneM Offline
                    Moshe LivneM Offline
                    Moshe Livne
                    Hero Member
                    wrote on last edited by
                    #27

                    @tbowmo SO, just re-iterating so I wont do something stupid:

                    1. I still need a bridge rectifier or some sort of ac-dc regulator/transformer to drive the arduino as the dc circuit does not have enough juice
                    2. the circuit will look something like:
                      edit#breadboard.jpg
                      (the simulation shows zero current so i probably did something wrong)

                    Again, thank you for your patience.

                    1 Reply Last reply
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                    • tbowmoT tbowmo

                      hmm.. only 6v DC?

                      why use optocouplers for that? Could also be done very simple with a resistor and one or two diodes.

                      connect gnd together, a 10-100k resistor in line with the +6V signal to the input on arduino, and a clamping diode to VCC (optionally a second clamping diode to GND for good measures).

                      See the first answer to the question here http://electronics.stackexchange.com/questions/45127/what-kind-of-diode-to-use-with-adc-inputs

                      Moshe LivneM Offline
                      Moshe LivneM Offline
                      Moshe Livne
                      Hero Member
                      wrote on last edited by
                      #28

                      @tbowmo added the door bell to the simulation and its working. you are the bestest! now to get some diodes.....

                      1 Reply Last reply
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                      • tbowmoT Offline
                        tbowmoT Offline
                        tbowmo
                        Admin
                        wrote on last edited by
                        #29

                        @Moshe-Livne

                        That doesn't look quite right. If you look at the link I provided, you will see that the resistor is in line with the signal from "outside" to the arduino. So 1 side goes to the doorbell, the other go to the arduino pin. Then the two diodes go from arduino pin and vcc, and arduino and gnd.

                        Moshe LivneM 1 Reply Last reply
                        0
                        • tbowmoT tbowmo

                          @Moshe-Livne

                          That doesn't look quite right. If you look at the link I provided, you will see that the resistor is in line with the signal from "outside" to the arduino. So 1 side goes to the doorbell, the other go to the arduino pin. Then the two diodes go from arduino pin and vcc, and arduino and gnd.

                          Moshe LivneM Offline
                          Moshe LivneM Offline
                          Moshe Livne
                          Hero Member
                          wrote on last edited by
                          #30

                          @tbowmo did I get it right now?
                          edit#breadboard (1).jpg
                          its a shame that they don't have ac power supply there so i can't simulate the rectifier. nifty site...

                          1 Reply Last reply
                          0
                          • tbowmoT Offline
                            tbowmoT Offline
                            tbowmo
                            Admin
                            wrote on last edited by
                            #31

                            @Moshe-Livne

                            Without knowing the details of the doorbell, I would think it is something like this.. That is, the doorbell get power, when the button is pressed, and makes a connection to GND. So this would be the circuit that I would create:

                            doorbell1.png

                            It's only the arduino part you should make, the rest is the existing doorbell.. The resistor should be high value, I've put in 56Kohm, but something in the order of 56-220K ohm, whatever you have in your parts bin :)

                            Moshe LivneM 2 Replies Last reply
                            0
                            • tbowmoT tbowmo

                              @Moshe-Livne

                              Without knowing the details of the doorbell, I would think it is something like this.. That is, the doorbell get power, when the button is pressed, and makes a connection to GND. So this would be the circuit that I would create:

                              doorbell1.png

                              It's only the arduino part you should make, the rest is the existing doorbell.. The resistor should be high value, I've put in 56Kohm, but something in the order of 56-220K ohm, whatever you have in your parts bin :)

                              Moshe LivneM Offline
                              Moshe LivneM Offline
                              Moshe Livne
                              Hero Member
                              wrote on last edited by
                              #32

                              @tbowmo I think its just about the same as my messy sketch. only thing is you assumes the grounds are the same, which should be ok. got a bridge rectifier as well but had to take the kids to watch minions. sigh....

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                              • tbowmoT Offline
                                tbowmoT Offline
                                tbowmo
                                Admin
                                wrote on last edited by
                                #33

                                @Moshe-Livne

                                It seems that you have the doorbell switch attached accross the supply, so you short circuit it, when you press it.

                                You also need a common ground signal, between the door bell, and the arduino.

                                Moshe LivneM 2 Replies Last reply
                                0
                                • tbowmoT tbowmo

                                  @Moshe-Livne

                                  It seems that you have the doorbell switch attached accross the supply, so you short circuit it, when you press it.

                                  You also need a common ground signal, between the door bell, and the arduino.

                                  Moshe LivneM Offline
                                  Moshe LivneM Offline
                                  Moshe Livne
                                  Hero Member
                                  wrote on last edited by
                                  #34

                                  @tbowmo oh this power supply represents the bell circuit but i see what you mean. If the kids will give me 10 min today I'll give it a try. Door bell is one of those things you can't do after they go to sleep

                                  1 Reply Last reply
                                  0
                                  • tbowmoT tbowmo

                                    @Moshe-Livne

                                    It seems that you have the doorbell switch attached accross the supply, so you short circuit it, when you press it.

                                    You also need a common ground signal, between the door bell, and the arduino.

                                    Moshe LivneM Offline
                                    Moshe LivneM Offline
                                    Moshe Livne
                                    Hero Member
                                    wrote on last edited by
                                    #35

                                    @tbowmo so, to get a common ground i just connect the "-" from the bell to the gnd on the arduino?

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                                    • tbowmoT Offline
                                      tbowmoT Offline
                                      tbowmo
                                      Admin
                                      wrote on last edited by
                                      #36

                                      @Moshe-Livne

                                      Yes, I would think so.. again, without having any knowledge to how the door bell is functioning..

                                      Moshe LivneM 1 Reply Last reply
                                      0
                                      • tbowmoT tbowmo

                                        @Moshe-Livne

                                        Yes, I would think so.. again, without having any knowledge to how the door bell is functioning..

                                        Moshe LivneM Offline
                                        Moshe LivneM Offline
                                        Moshe Livne
                                        Hero Member
                                        wrote on last edited by
                                        #37

                                        @tbowmo Oh I wish I knew. I might just open it and look although it will be a big hard to put back. currently the power from the bridge seems to be not enough to drive the circuit which is strange. the power lights up but nothing much happens. I'll go over everything once again.

                                        1 Reply Last reply
                                        0
                                        • tbowmoT tbowmo

                                          @Moshe-Livne

                                          Without knowing the details of the doorbell, I would think it is something like this.. That is, the doorbell get power, when the button is pressed, and makes a connection to GND. So this would be the circuit that I would create:

                                          doorbell1.png

                                          It's only the arduino part you should make, the rest is the existing doorbell.. The resistor should be high value, I've put in 56Kohm, but something in the order of 56-220K ohm, whatever you have in your parts bin :)

                                          Moshe LivneM Offline
                                          Moshe LivneM Offline
                                          Moshe Livne
                                          Hero Member
                                          wrote on last edited by
                                          #38

                                          @tbowmo I have double checked everything, used the arduino connected to the computer so have a stable 5v power supply to the nano. connected external power supply with 6.3v and 8ma to ground and the external leg of the resistor - nothing...
                                          wouldn't it be simpler it I used npn transistor to close the circuit? I am on the verge of going the "safe" way - connecting the doorbell loop to the arduino so pressing the doorbell will short pin 3 to gnd and then activating a relay to close the doorbell circuit. this is far from being a good solution as if the sensor does not work the doorbell will not work as well, but this is stuff that I understand (to an extent :-) )

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