help with DM74LS190N

Discussion in 'The Projects Forum' started by Abin, May 31, 2012.

  1. Abin

    Thread Starter New Member

    May 31, 2012
    5
    0
    I'm trying to buld a circuit that wuld count objects on a conveyor belt. the ICs are-DM74LS190(counter), 7447 and 555. i havent had a problem with 7447 and the display but the 555 trigger circuit and counter are a noose around my neck.:( i try to preset the counter by grounding load and the parallel data inputs but nothing happens. the output just remains in 1110(- this is impossible right? because 74190 is a decade counter) and the latch input 4 is grounded only. i need urgent help as i need to finish my project in 3 days:rolleyes: pls help!! ty!1
     
  2. Abin

    Thread Starter New Member

    May 31, 2012
    5
    0
    and clocking pulses dont make any difference either wen 5 is high or low:eek:
     
  3. absf

    Senior Member

    Dec 29, 2010
    1,493
    372
    Is enable "E" pin 4 grounded?

    Allen
     
  4. Abin

    Thread Starter New Member

    May 31, 2012
    5
    0
    yes 4 is grounded and i have also tried connecting it to Vcc. but no change. how can the o/p be 1110? in decade counter 1001 is the max possible right:confused:? pls help:)
     
  5. absf

    Senior Member

    Dec 29, 2010
    1,493
    372
    If you want to count down from 9-0, the input has to be set as 1001 like this....
     
  6. Abin

    Thread Starter New Member

    May 31, 2012
    5
    0
    i havent used the 10k resistor pulled up from PL. and i have grounded pin5. other than that, everything is the same sir. but not working:confused:. pls help!!!
     
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