Convert doorbell chimes to wireless

Discussion in 'The Projects Forum' started by Leclanché, Dec 1, 2013.

  1. Leclanché

    Thread Starter New Member

    Nov 29, 2013
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    Having had a new £1050 front door fitted I did not want to drill the frame to reconnect the rather nice tubular chimes so bought a wireless chime and am attempting to use the TX and the RX portion to close the chime circuit.
    The chime runs on 6V from 4 type C cells. The RX was mains stepped down and rectified.
    This is as far as I have got. See attachment.
    Vcc is 3.5v. No LED was installed, but from the solder pads I can see a fluctuating voltage in step with the tune. There is of course a trigger pulse from the decoder. I do not own a scope so things are a little hazy from here!What I need now is a circuit to replace the old bell push ie make (ding) and break (dong) and I shall be home and dry. Any ideas will be appreciated.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I must be missing something, the T.N. looks like the receiver or chime which should be no problem, Isn't it the TX you want to trigger somehow?
    Max.
     
  3. t06afre

    AAC Fanatic!

    May 11, 2009
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  4. #12

    Expert

    Nov 30, 2010
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    I have had a customer waiting for a GOOD wireless door bell for a year. Everything I can find will not work as advertised. The best of them fail 4 out of 5 times at 25 feet, line of sight. Not a chance they can go 50 feet and around 2 corners made of grounded concrete walls. Please post if you find quality!
     
  5. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    I would look at the receiver cct to see if it gives a dc voltage pulse out when you press the door bell TX,and use that to trigger a 555 timer and relay.
     
  6. Leclanché

    Thread Starter New Member

    Nov 29, 2013
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    The decoder gives a trigger pulse (I can only see the volt meter jump, having no scope to see it's shape) witch I am sure can be used to trigger a 555. I guess what I should be asking for is the 555 circuit details required to be triggered by that pulse and then give me a suitable square 'ding dong' pulse.

    My basic problem is that I am a 82 year old wind up watch man in a digital world :D
     
  7. t06afre

    AAC Fanatic!

    May 11, 2009
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    I would also recommend using an optocoupler to isolate the the ding-dong bell from the receiver unit
     
  8. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Doable. What voltage/current does the tubular chime require? Is the pulse a positive-going one relative to the battery -ve?
     
  9. t06afre

    AAC Fanatic!

    May 11, 2009
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    My guess is that old bell is AC fed froma a transformer
     
  10. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    Here is a timer cct that will give out a pulsed relay for upto 4 seconds, make the 220k resistor a variable one, if the pulse from the receiver is a posative one then connect it to the 10K resistor to trigger the transistor, if its a negative pulse then connect it to pin 2 direct.

    use the relay to connect the original door push.
     
    Last edited: Dec 2, 2013
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  11. Leclanché

    Thread Starter New Member

    Nov 29, 2013
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    Thank you. I will give that a try. It will take a little time, but as Arnie says "I'll be back."

    Sorry about the double posting :D Finger trouble!
     
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