Problems using 4000 ic

Discussion in 'The Projects Forum' started by Twiggy12345, Oct 24, 2014.

  1. Twiggy12345

    Thread Starter New Member

    Oct 24, 2014
    2
    0
    I am trying to make a circuit that is using a ldr with a 9v battery to power 3 4000 ic. A 4001, 4081, and a 4071. The outputs are connected up to transistors. Everything works fine for two of the outputs, but, the last ic is putting out a flashing Led rather than a solid signal.
    I tried swapping the ic over like musical ic, but the new ic I put into the original spot has flashing and the ic I pulled out of that spot is now fine, a solid light.

    Are the 4000 series gates supposed to flash or do I not have enough amps going in or something?
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,439
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    We cannot provide an educated answer without seeing the circuit schematic.
     
    Last edited: Oct 24, 2014
  3. crutschow

    Expert

    Mar 14, 2008
    13,001
    3,229
    4000 gates do not flash. Post the circuit diagram.
     
  4. Papabravo

    Expert

    Feb 24, 2006
    10,138
    1,789
    A 4000 series chip can do either. It can flash or output a solid signal. In order to do what you want it to do it absolutely must be wired correctly. Post a schematic and any pictures you might have.
     
  5. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
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    Its a hopeless, nonsense, spammy post- its obvious nobody can know an answer without to know the schematic.
     
  6. Twiggy12345

    Thread Starter New Member

    Oct 24, 2014
    2
    0
    I haven't shown the transistors because the led flash even going through the transistor or through the ic.
     
    Last edited: Oct 24, 2014
  7. Papabravo

    Expert

    Feb 24, 2006
    10,138
    1,789
    You asked in a private conversation about how to make the chips do various functions. I prefer that questions be asked and answered in the open forum. I'll explain how I would use a 4001, which is a quad 2-input NOR gate to do the three functions.

    Using DeMorgan's law we can think of this gate as performing 2 identical functions described this way:

    1. A high .OR. a high is a low
    2. A low .AND. a low is a high​

    Let us say that when the output is high the LED will be on and when the output is low the LED will be off.

    To make the LED be on, we need both inputs to be low all the time.
    To make the LED be off, we need either input to be high all the time
    To make the LED flash, we need one input to be low, and the other input to be alternately high, then low, then high again and so on.​

    Have you got it now? Can you work out the details for the remaining parts?
     
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