Digital Counter rushed in Counting.

Discussion in 'The Projects Forum' started by MortalAl, Mar 17, 2010.

  1. MortalAl

    Thread Starter New Member

    Mar 17, 2010
    2
    0
    Hi there.

    Good afternoon from New Zealand.

    I got a rather simple but rather troublesome question. At the moment I am working on a project which deals with Timers/Relays/Limit switches and a Electronic based digital Counter (PRO-CTR100 from TexmateNZ).

    Everything seems to be working according to what I am trying to do at the moment. I have a pressure switch feeding a OMRON MK3PN-5-I. The relay is a 24VDC supplied from a simple transformer with 1A. Once the pressure switch changes from Normally closed to Normally open. In this case the pressure has reached the desired value in the cylinder. The timer is feed from a 230VAC 50HZ Mains supply from one of the contacts on the relay. So this should turn on a timer which operates for one second then outs, which is when the counter should count (1 cycle per outs of the timer).

    Till now the project works a treat. However I have a Limit Switch being feed from the same Relay (OMRON MK3PN-5-I) by the mains supply (240VAC 50HZ). Of course not using the same contact as the timer rather a different contacts. Once the Limit switch is turned on (pressed) it sends a signal to starter which holds the Solenoid on till another limit switch is activated which in turn turns off the Solenoid. So that all works. :)

    What I am struggling with is why the counter counting. I have the counter leads contacted to the timer contacts. I have it in a way so that every time the timer Outs then the contacts of the counter are contacted and the counter should count 1 cycle. When the limit switch is activated it shouldn't be counting, its just an indication to let the solenoid turn On/Off to reverse the oil direction so that the pressure pistons go back to bottom so that the cycle can start again. :(

    I would appreciate any help I can get with this. As this would be my final stage in the project till I can wire it to the actual rig. At the moment it's only test circuit. Thank you in advance

    Cheers

    Mortada
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Chatter or bouncing could cause rapid counting in the relay. You could try a cap in line to the counter IC to try to debounce the signal.


    Or it could be AC in the signal. So the counter will be counting for each swing of the AC wave.
     
    MortalAl likes this.
  3. MortalAl

    Thread Starter New Member

    Mar 17, 2010
    2
    0
    Hi Retched

    I just went back to working on project after been sick! :S

    I took your advice and it was reading the AC signal as you mentioned.

    I have since then redesigned the circuit for the specification and all is well.

    I Want to thank you for your input, much appreciated.

    Thanks
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    You are very welcome. Im glad all is working well.
     
Loading...