Problem with "Relay"

Discussion in 'Homework Help' started by Ma7amed, Sep 7, 2010.

  1. Ma7amed

    Thread Starter New Member

    Sep 7, 2010
    6
    0
    Hello,

    I have a problem with realy. I made a circuit that control a lamp using any IR Remote. it works so good but the problem is with the relay part.

    When the circuit is connected to power and to the lamp, and any other lamp in my home or any other device is turned on or off, the relay is turned on or off (according to what it was ).
    and also if i connected this realy to a fan (to turn it on or off), the relay turn off just when i change the speed of the fan.

    I want a solution for the relay so it donn affect my circuit and the other devices in my home donn make it turn on or off.

    Here is an image of the circuit I made. Note: I added the diode on the circuit but it doesn't solve the problem.


    [​IMG]

    Please help me, I need to make this circuit work urgently
    ;)
     
  2. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    Try reducing the R1 220K to 2.2K and see if the false triggering disappears.
     
    Last edited: Sep 7, 2010
  3. Ma7amed

    Thread Starter New Member

    Sep 7, 2010
    6
    0
    I will try it and tell you what happens
     
  4. Ma7amed

    Thread Starter New Member

    Sep 7, 2010
    6
    0
    I tried it but the problem increased. Sorry it didn't fix the problem
     
  5. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    No problem. Let's try another way. This time an RC filter for the supply bypassing of 4017 and the IR decoder.

    The capacitor value is not critical but should be higher than 47uF. You can use resistor values between 33Ω to 100Ω.

    [​IMG]
     
  6. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,164
    Is the fan speed control "remotely" operated with an IR device?

    I don't see where your circuit discriminates authorized IR signals from unauthorized IR signals, so anytime it receives an IR command from any IR remote ... the relay changes state.
     
  7. Ma7amed

    Thread Starter New Member

    Sep 7, 2010
    6
    0
    The fan speed in controlled by the fan buttons not in the circuit, I but the fan instead of the bulb in the circuit.



    I donn have these values, I will buy them and try (note: I didn't add the 47 resistor that near the IR reciever 1738 cuz i thought it is useless, is it may be the cause of the problem too ???)
     
  8. n1ist

    Active Member

    Mar 8, 2009
    171
    16
    I'd also add a 100nF cap from pin 8 to pin 16 on U1; 4017s can be rather sensitive to power line glitches.
    /mike
     
  9. Ma7amed

    Thread Starter New Member

    Sep 7, 2010
    6
    0
    I forget to tell you that all my tests of the circuit is done in a bread board, can it be a cause for this problem too ???
     
  10. Ma7amed

    Thread Starter New Member

    Sep 7, 2010
    6
    0

    I tried that but still the problem exist. :(

    Do you have any other thing to try ????
     
  11. Markd77

    Senior Member

    Sep 7, 2009
    2,803
    594
    From the sensor datasheet:
    Try adding the resistor and capacitor recommended.
    [​IMG]
     
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