RC Circuit? Delay closing only

Discussion in 'General Electronics Chat' started by Joe Sgroi, Jun 15, 2016.

  1. Joe Sgroi

    Thread Starter New Member

    Jun 15, 2016
    3
    0
    I am built a simple device but it is causing an initial "jitter" when I turn it on and off.

    I need to build something to open the circuit for 1/2 second when turned on then close the circuit. Same for when I turn it off, open the circuit for 1/2 second then close.

    I do not think a 555 timer will work here but if it will please tell me how. The best design I can come up with is two DPDT relays, one delayed by a RC circuit.

    Any advice is appreciated.

    Please see my attached pictures.

    Thank you.
    PS this is my first post and I am new to building PCB's. 1238C.jpg 1238C_01.JPG
     
  2. dl324

    Distinguished Member

    Mar 30, 2015
    3,235
    619
    Welcome to AAC!
    What do you mean by "jitter"?
    Draw a block diagram showing what power is available after the circuit is turned off.

    I'm not even going to try to read your schematic. A well drawn schematic will convey function at a glance. You're schematic has many wire crossings, unnecessary jogs, and inconsistent use of connection dots.
     
  3. Joe Sgroi

    Thread Starter New Member

    Jun 15, 2016
    3
    0
    OK I am working on a better drawing now.

    The "jitter" is the power being sent through a wire when I flip the switch. This comes from a ECU trying to do what it normally does but once it reads the resistance it cuts the power to that wire. So disconnecting that wire for 1/2 a second fixes this issue.
     
  4. Joe Sgroi

    Thread Starter New Member

    Jun 15, 2016
    3
    0
    I hope this drawing allows you to understand what I am trying to do. 1238C_02.JPG
     
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