1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

InterCom / Door Phone

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by Non89, Nov 11, 2010.

  1. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,434
    Likes:
    933
    Location:
    Canada, of course!
    ONLINE
    Make a video of the circuit blowing up when you power it with AC.
     
  2. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    what can i add to let the user have an authorize to shut down the "slave" when no visitor ?

    So that are no more environment sound sent through the "master" and also the master can stop annoying ....
     
  3. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,434
    Likes:
    933
    Location:
    Canada, of course!
    ONLINE
    Most intercom calls are dialed then at the end of a call are disconnected.
    You don't want the system left turned on so that a person outside at the slave can hear everything at the master and you don't want the master to hear all the noise outside at the slave.

    Have a doorbell. When the person inside at the master hears the doorbell then the intercom power is turned on for the call and turned off when the call is finished.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0

    yaya, i want intercom at the end of a call are disconnected, person outside at the slave cannot hear everything at the master.....
    if i want to have a doorbell , how can i connect doorbell togather with the intercom ? doorbeel output is connected to the "master" or "slave"... and after end of communicating , how i can stop both intercom , so i need to addition a switch off button?
     
  6. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,434
    Likes:
    933
    Location:
    Canada, of course!
    ONLINE
    The doorbell is completely separate from the intercom. The person at the master can use the intercom when he wants.

    The switch simply connects or disconnects the power supply to the intercom circuit.
     
  7. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    oic... that mean i need to connect both intercom within same power supply , so i can close both if i m not using ?
     
  8. Shyamal

    Shyamal New Member

    Joined:
    Jan 6, 2011
    Messages:
    92
    Likes:
    0
    Location:
    Khulna, Bangladesh
  9. Boncuk

    Boncuk New Member

    Joined:
    Nov 10, 2007
    Messages:
    5,382
    Likes:
    88
    Location:
    Phetchabun,Thailand
    The intercom is fitted with a latching DPDT switch (PRIVATE) which interrupts outgoing speech when in the position "SILENT".

    To avoid outside noise to be heard inside the house use the volume knob. Turn it all the way CCW for zero volume.

    When somebody rings the door bell release the private switch and turn up the volume.

    You could also use a microprocessor and disable the entire intercom until somebody rings the bell.

    You might also want to connect a sound recording module to tell the visitor you are not at home when he rings the door bell. :)

    Boncuk
     
  10. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    boncuk , does the circuit work well ? you try before?
     
  11. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,434
    Likes:
    933
    Location:
    Canada, of course!
    ONLINE
    the original project is at www.redcircuits.com called Full-duplex Intercom and looks like it will work well.
     
  12. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    ya... but boncuk edit some part....and the shielded cable connected part is different also....
     
    Last edited: Jan 10, 2011
  13. Boncuk

    Boncuk New Member

    Joined:
    Nov 10, 2007
    Messages:
    5,382
    Likes:
    88
    Location:
    Phetchabun,Thailand
    I guess it won't be difficult to recognize the difference between "SW1" and "S1" as well as "Q1" and "T1".

    Since Eagle would connect circuits with the same net names different names were used, e.g. "AF-A1" and "AF-A2", both connected at the junction of the transistor collectors (T1) and C3 and T1A and C3A respectively.

    The shielded cable connects exactly at the same connection points with the difference, that a three wire shielded cable is used connecting the power supply from the master board to the slave board.

    When using a single wire shielded cable connect that to pins2 and 3 of the connector with pin2 being the "hot wire" (labeled "AUDIO" on the PCB design) and pin3 being the shield (labeled "SHIELD").

    Use an unshielded two wire cable to connect pins1 (+12V) and pins4 (circuit ground) between boards.

    I tested the clarity of the board layout asking my 12 year old stepdaughter where she would connect both boards and her answer was: "just 1:1 as labeled".

    Boncuk
     
    Last edited: Jan 11, 2011
  14. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    i m using shield 4-wire cable, so i just connect as shown?

    and i need 2 power supply , 1 is for "master" , another for "slave" ??
     

    Attached Files:

    • qqe.GIF
      qqe.GIF
      File size:
      24.8 KB
      Views:
      236
  15. Boncuk

    Boncuk New Member

    Joined:
    Nov 10, 2007
    Messages:
    5,382
    Likes:
    88
    Location:
    Phetchabun,Thailand
    You need two cables:

    One two wire unshielded cable to connect the 12V power source to the solder pads on the master PCB. Those solder pads are only present on the master PCB and they are located halfway between connector Y1 and C7. They are labeled "+12V" and "GND".

    The second cable should be a four wire shielded cable (If you can get 3 wire shielded cable it will suffice as well.)

    I redrew the wiring since I don't like thick lines crossing parts and text in a schematic layout.

    Additionally to the wires connecting pins I added a small sketch showing the pins labeled MA1 through MA4 and SL1 through SL4 which stand for master and slave.

    Using a four wire cable it won't hurt if you connect the fourth wire to the shield.

    If that drawing doesn't help you now I'm afraid nobody can help you.

    Boncuk
     

    Attached Files:

    Last edited: Jan 11, 2011
  16. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    i was tried the circuit on board , but it doesn't work well .....
     
  17. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    any software can let me try the circuit in pc, i want to retry it.....

    i can't find the TDA7052A chip at multisim .... the data is not completed
     
  18. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,434
    Likes:
    933
    Location:
    Canada, of course!
    ONLINE
    Please tell us the details about what did not work well. Acoustical feedback? Hiss? Hum? Distortion? Not enough output level? Boomy speakers?

    There are hundreds of low power amplifier ICs available. Use a TDA2822M or LM386 instead.
    Why simulate a simple audio amplifier when all its spec's are in its datasheet?
     
  19. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    i try a part at multisim , the voltage is low , same like what i tried at board.... and i get zero output on speaker
     

    Attached Files:

    • aa.JPG
      aa.JPG
      File size:
      225.7 KB
      Views:
      168
  20. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,434
    Likes:
    933
    Location:
    Canada, of course!
    ONLINE
    Your Multisim schematic shows a transistor with no input signal and its base is disconnected from its base bias resistors. So of course there is no output.
     
    Last edited: Mar 1, 2011
  21. Non89

    Non89 Member

    Joined:
    Nov 1, 2010
    Messages:
    105
    Likes:
    0
    wrong post, sorry
     

    Attached Files:

    • aa.JPG
      aa.JPG
      File size:
      188.4 KB
      Views:
      147

Share This Page