556 timer problem

Discussion in 'The Projects Forum' started by kirkyj78, Jan 19, 2008.

  1. kirkyj78

    Thread Starter New Member

    Jan 19, 2008
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    0
    Hi, can anyone help me i am using 556 timer to turn an led on for 2 mins & to turn a relay on for 30seconds which in turn switches a solenoid on, the problem i have is when the solenoid switches it causes the timer to reset or switch off, i do have a diode in reverse across the relay and another from the output of the 556 timer, i guess EMF is the problem, i just don't know how to solve it?????

    thanks
     
  2. hgmjr

    Moderator

    Jan 28, 2005
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    Can you post a copy of your schematic?

    hgmjr
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    The bipolar version of the 556 can sink up to 200mA, the CMOS version sinks less.

    What is the exact part number of your 556?

    How much current does your relay's coil require?

    What are you using for a power supply?
     
  4. gee_emm

    Active Member

    Jan 16, 2008
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    Im pretty new to electronics myself, but maybe you can use an optoisolator between the 556 and relay, to kind of keep them electrically seperated. I discovered them after blowing up a basic stamp.
     
  5. kirkyj78

    Thread Starter New Member

    Jan 19, 2008
    7
    0
    hi,
    Thanks for the reply's

    the chip is an Ne556n
    12v dc

    The problem is the solenoid even though it is driven through a relay.

    If i disconnect the solenoid the circuit work's fine.

    thanks
     
  6. kirkyj78

    Thread Starter New Member

    Jan 19, 2008
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    0
    hi, how do i put a circuit diagram on here, i used pcb wizard to design it so it would not be in the correct format.
     
  7. hgmjr

    Moderator

    Jan 28, 2005
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    Does you design software permit you to save or export the file into PNG, JPG, or TIFF format?

    hgmjr
     
  8. kirkyj78

    Thread Starter New Member

    Jan 19, 2008
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    0
    no unfortunatly not, i wondered if i should print it then scan it and save it in a different format, seems a long way of doing it though
     
  9. hgmjr

    Moderator

    Jan 28, 2005
    9,030
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    That should work. Why don't you give it a try?

    hgmjr
     
  10. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
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    You can download any of a number of freeware or shareware screen capture programs to get around having to print and scan.
     
  11. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    If you're using Windows, you can capture a screen shot like this:
    1) Get your screen how you want it to look.
    2) Hold down the Ctrl key and tap the PrtScr key
    3) Start Windows Paint (in Accessories)
    4) Edit/Paste or Ctrl+V
    5) File/Save As...
    I suggest saving it in either .jpg or .png format, as the resulting file size will be much smaller than the other formats.
     
  12. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    You can capture the active screen with alt-prnt scrn, then paste it into paint, then save as a jpg or gif or png.

    ctrl-prnt scrn will place your whole desktop on the clipboard for pasting.
     
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