Relay Basic help

Discussion in 'The Projects Forum' started by Chris15, Dec 16, 2009.

  1. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    Hey
    If i have power coming to a relay at the flick of a switch how do i make it latch, and then with the same power whenever i want later to unlatch it.

    I have a Christmas light show set up and i have a wireless doorbell circuit and i can power the relay with the speaker power with some adjustments i made. i need to be able to press the doorbell button and have the relay latch and when i press the button again it un-latches and the lights go off.

    I am sure this circuit may be simple but if anyone could give me some direction or a schematioc because i have no idea

    Thanks Chris
     
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Can you explain this a little more...sketch?...schematic?.

    Ken
     
  3. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    Here i have replaced the speaker with the relay on the Doorbell receiver, and added 9V so when button is pressed the relay click's. (i can hear the chime mildly in the relay coil) but when the chime is finished the relay click off i need it to stay until i press the button again

    Thankyou, Chris
     
  4. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    This looks like a really bad idea. The output to the speaker is probably pulsating DC (chime tone)...or may be AC, if it's a real speaker and not a Piezo transducer. You would need a circuit to detect the speaker signal...rectify, filter and amplify it...and drive a flipflop circuit that would drive the relay.

    Ken
     
  5. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    Ok
    I have seen people who have done what you said they use the pulsating, but i cant find a schematic of how this is done. If you know any links to schematics or you know the schematic could you please tell me ho i can make this wirk.

    This is the Guy that does it, but no schematic
    http://www.youtube.com/watch?v=_rWdxJqjUYU&feature=channel

    Thankyou Chris
     
  6. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Chris,

    As you said, no details. What a waste of time. I wonder why he bothered, other than "look at me".

    OK, how are you at building electronic circuits? What we're looking at is basically the "CLAPPER" ("AS SEEN ON TV!") circuit. This is one someone apparently has done.

    http://hibp.ecse.rpi.edu/~connor/education/EI_archives/Proj4_f00.PDF

    R1 and MIC would be eliminated.

    Ken
     
  7. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    so do you have like a Schematic cause i need to build this thing quick sorry. why do i need a clapper, cant i latch then unlath with the press of the button in controll of another circuit.

    Anything that will turn on with one press and of with another is all i need.

    Thanks Chris
     
  8. rjenkins

    AAC Fanatic!

    Nov 6, 2005
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    Hi,
    you can buy 'impulse relay' modules, typically to control industrial lighting, which alternate On & Off with each pulse of power.

    Example data:
    http://www.farnell.com/datasheets/313043.pdf

    In the type I've used previously, the coil+armature rotate a cam through a ratchet system, and the cam in turn operates the contacts.

    You will still have to make sure the power from your control circuit is appropriate to drive the coil on whatever relay you select.
     
  9. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    ok thank you i have a start now but remember the voltage from the doorbell is 3V, but before i use one of these i still want to know if i could create a circuit with maybe some transistors and the input voltage so that when the dorbell power goes through the circuit it activates the relay and when the power comes again it turns the trasistor off unlatching the relay

    What would this circuit be called?

    Thanks, Chris
     
  10. rjenkins

    AAC Fanatic!

    Nov 6, 2005
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  11. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    Ok but i am sort of new to IC's and digital's flip flop could you explain this a bit more of have a scematic?

    Thanks Chris
     
  12. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    could you post a schematic?, i have heard or flip flop's before but i have never used them, i just thought this circuit would be easy

    Chris
     
  13. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    Could you post like a schematic because i am new to flip flop circuits
    If there is a circuit that will do what i want if you get more info from all my posts, just tell me the name and i can research it

    Thankyou Sorry for the incon

    Chris
     
  14. k7elp60

    Senior Member

    Nov 4, 2008
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    If you are willing to use two doorbell switches I can show you how to wire up a double pole double throw relay to latch with on button and unlatch with the other. No F/F's needed
     
  15. ns21

    New Member

    Dec 19, 2009
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    You can use two DPDT Relays to achive that. if you need more deteils i will try to explain since i have no way of sending you a diagram... good luck.
     
  16. Harrington

    New Member

    Dec 19, 2009
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    There is a far easier way of achieving this and very simple Use a pic508A processor available from maplin electronics You can make one of the port pins a switch and program the Pic processor to latch or unlatch depending on the switch count Would you like a circuit for this + the programming If so leave a message also I need to know what voltage you intend to power the relay with together with the current rating of the relay The intended supply that you wish to use and Ill put my brains together very quickly for you and come up with a nice neat solution + circuit PCB Layout which you can then make !!
     
  17. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    OK
    i would prefer to wire it up with the 2 relays could you show me how to wire the 2 relays up and you can watvh the video i am reffering to in my previous post it is a youtube link, he uses 2 relays but he has another circuit and he says he uses the pulses, i think i need a circuit that detects the pulses and give me a steady power source.

    If you could help please Christmas is Coming and i need it by then
    Thnakyou,
    Chris
     
  18. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    I would Appreciate this circuit very much, i just want to know if it is hard to make becausei always get intimidated when i hear programming chips but if it will work and its not too big then yes i would like if you could to do that.

    The power coming out of the doorbell wires i measured at 3V DC i am told that because of the speaker pulses it may be AC but i connected an LED (RED) and pressed the doorbell button and it light up and then turned of when the chime was finished. If i looked closley i could see the LED mildly flicker with the different Ding ding DONG sounds.

    Chris
     
  19. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Not sure where you want to put your effort, but if you want to buy and assemble a kit, this is essential the type "clapper" circuit that I referred to earlier. http://www.electronickits.com/kit/complete/elec/ck1607.htm Again since I don't know your exact chime circuit, so I'm using an educated guess. As before, you would not use the input resistor or microphone. You would hook the "common" and input capacitor to your "speaker connections. You would neeed to buy an external relay, per the assembly manual. And I would use a 9VDC wall-wart instead of a battery.

    Ken
     
  20. Harrington

    New Member

    Dec 19, 2009
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    Hi Chris this is the circuit for you I have yet to prepare the code and pubs design but have just put this together for you very quickly so that you can see how this is done Please note though that this is solely for purposes of enjoyment I will prepare the PCb layout for you and coding hopefully by Tuesday this week

    The only other problem that i foresee is the possiblilty of maybe having to add an opto coupler to the input so that you can use the arrangement as shown in your circuit so may need to make a little change here and there Not to worry Im sure we will get there

    In the meantime if you have any questions please free to ask and ill see what I can do to assist

    Best of luck with this Mark
     
    Last edited: Dec 20, 2009
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