555 Set up to latch BCD for LEDs

Discussion in 'The Projects Forum' started by dyeraaron, Nov 8, 2008.

  1. dyeraaron

    Thread Starter Active Member

    Oct 27, 2008
    Hello All......so my project for ITT has been frustrating me...actually I've been so consumed with it I was kind of disappointed when it didn't work properly....so anyways.........If you can picture 2 7493 decade counters counting properly but when they go into my inputs of 2 7475 Latches, my BCD in my LEDs doesn't display what I'd like. I've got my 555 timer output tied into each 7475 Enable. All LEDs flicker or count but they don't latch and I need them to do so and slow down as well........I know the Frequency for the 555 timer is set up by taking 1.44 / (R1 + 2(R2)) (C) for starters I had 2 100 K resistors and a .01uF Cap but listening to my instructor explain that I was lost...he was saying slow each period down to latch 1 per second.....Please help.
  2. Wendy


    Mar 24, 2008
    Standard starting query #1... Schematic please?