Reset Circuit Problem

Discussion in 'The Projects Forum' started by ksaomar, Nov 6, 2014.

  1. ksaomar

    Thread Starter New Member

    Nov 6, 2014
    3
    0
    Hi there

    I would like to use the reset circuit you see in the attachment in a system that can reset the whole system by disconnecting the +12V from the InputVoltage for two seconds and then connecting the +12V to the InputVoltage again. InputVoltage supplies the system and +12V supplies only the reset circuit. The reset signal (when it is high) comes from the system itself.

    I have this design but for some reason it woks for some boards and not to all boards, Do you think it is a problem in the design?


    Regards,

    Omar
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    Did you really leave pin 4 and 5 unconnected?
     
  3. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
    2,504
    380
    hi,
    It not a good idea to leave pin #4 Reset pin, floating, connect it to +V
    E
     
  4. ksaomar

    Thread Starter New Member

    Nov 6, 2014
    3
    0
    When I designed, I was assuming pin 4 has an internal pull up resistor. I checked it now, it does not?! I think I need to connect it to +V. Thanks a lot for the help.

    Is there anything you think it makes does not work all the time?
     
  5. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
    2,504
    380
    hi,
    Have you also considered Mike's point about pin #5 floating.?
    E
     
  6. ksaomar

    Thread Starter New Member

    Nov 6, 2014
    3
    0
    Thank you so much guys for your help, I think I will redesign it, high in pin 4 and a small capacitor to ground in pin 5.

    I am sure this will help thank you so much guys for the amazing support.
     
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