Designing relay circuits.

Discussion in 'The Projects Forum' started by Ongsl, Apr 19, 2013.

  1. Ongsl

    Thread Starter New Member

    Apr 18, 2013
    3
    0
    Hi all,

    I have some problems on designing the relay circuits:

    Conditions:

    a) I require a momentary switch to latch On/Off LED using non latching relays. Meaning if I press the switch, the On LED lit and if I release the switch, On LED is still lit. When I press the switch again, the Off LED lit and remain lit after I realease the switch and On LED will not lit.

    The LEDs toggles and latch each time I pressed and depressed the momentary switch. The LED is powered by 12Vdc.

    Could someone guide me in this using some drawings? Many thanks for your help.
     
  2. Ongsl

    Thread Starter New Member

    Apr 18, 2013
    3
    0
    Hi all,

    I have some problems on designing the relay circuits:

    Conditions:

    a) I require a momentary switch to latch On/Off LED using non latching relays. Meaning if I press the switch, the On LED lit and if I release the switch, On LED is still lit. When I press the switch again, the Off LED lit and remain lit after I realease the switch and On LED will not lit.

    The LEDs toggles and latch each time I pressed and depressed the momentary switch. The LED is powered by 12Vdc.

    Could someone guide me in this using some drawings? Many thanks for your help.
     
  3. crutschow

    Expert

    Mar 14, 2008
    13,056
    3,245
    Ongsi, please don't hijack another person's thread. You should start a new one of your own.
     
    Ongsl likes this.
  4. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    Taken care of.
     
    Ongsl likes this.
  5. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    Searching on AAC or google as : toggle switch using 555.
     
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,395
    1,607
    Since there is no time element to the spec a 555 is a poor choice.

    This has all the makings of a toggle type flip flop. One has to be careful using those as the switch needs to be debounced to work reliably, though an IC flip flop typically come in pairs you get a 2nd flip flop to act as a debouncer.
     
  7. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    Actually I didn't use NE555 like toggle switch, I always like to using 74HC14 and CD4013 to do the job, I have using a flip flop to replace the 74HC14 for debounce, but that circuit not test yet.

    [​IMG]

    I don't know why the people want to using NE555 as a toggle switch, it seems not stable to me.
     
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