IC Binary Counters with limited frequencies?

Discussion in 'General Electronics Chat' started by Fuji, Dec 13, 2014.

  1. Fuji

    Thread Starter Member

    Nov 8, 2014
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    Is the frequencies of binary counters limited to what resistors and capacitors are used along with it just like the 555 timer? It seems I can't get around to output a frequencies of the number that I choose. Like 1.5815Hz or, 1.635Hz, or 1.7021 Hz.
     
  2. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    It shouldn't be limited to fixed frequencies, especially of so low values. To what binary counters are you referring? Do you have the chip's number and specs?
     
  3. lightingman

    Senior Member

    Apr 19, 2007
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    Binary counters do not use resistors or capacitors like the 555. The 555 is a multivibrator and can be used o generate a square wave to drive the binary counter. There is a binary counter available that has the capability of being used with its internal clock and that is the CD4060. It can be used with a crystal and a couple of capacitors. The maximum count frequency of it is around 5Mhz.

    Daniel.
     
  4. Fuji

    Thread Starter Member

    Nov 8, 2014
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    Thanks for the reply. I am using HCF4060B 14-STAGE RIPPLE BINARY COUNTER/DIVIDER AND OSCILLATOR.
     
  5. Fuji

    Thread Starter Member

    Nov 8, 2014
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    Thanks for the reply. I'm using HCF4060B.

    I was told a crystal is more accurate than the binary counter with an internal clock. I have a 32Khz crystal im using with it. I need it to drop to a small frequency of 1.5815 Hz as a square wave output. To get the exact number of frequency like this, I was told the counter would need a few resistors/capacitors to be divided. What would be your suggestion?
     
    Last edited: Dec 13, 2014
  6. cmartinez

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    Jan 17, 2007
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    It seems that your chip uses an external oscillator for it to run, which according to its datasheet can be either an RC or a crystal type. For an RC oscillator to work properly, you need to work with at least 7V (as stated in pg 9)
    In fact, the example shown in pg 10 is calculated with a voltage of 10V
     
  7. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    On the other hand... it would be real hard to build an accurate RC oscillator working at such low frequencies, since commercial capacitors have a tolerance of at least 10% and common resistors 5% or more.
    I'd seriously consider using a higher frequency crystal oscillator running through a frequency divider to get the low frequencies that you're looking for
     
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  8. k7elp60

    Senior Member

    Nov 4, 2008
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    I have had real good luck using mylar capacitors with the 555 as an oscillator. Since you are using the CD4060 binary divider, I have a suggestion. Set the 555 at 404.864Hz and divide by 256 which is output pin 14 of the 4060. The 555 output would be connected to pin 11 of
    the 4060. 404.864Hz/256=1.5815Hz. 256 is 2 to the 8th power.
     
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  9. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    A 32kHz crystal can not produce 1.5815Hz by binary division. Be aware that an RC oscillator (as post #8) will not be stable to 1 part in 15815 unless extreme precautions (including accurate temperature control) are taken.
     
  10. Fuji

    Thread Starter Member

    Nov 8, 2014
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    Thanks for the reply.

    Would it be easier to use a 32.768kHz crystal cylinder which in the binary counter would be equal to 2 to the power of 15=32 768 Hz? The frequency from Pin 3 (O13) from the binary counter pin would be exactly at 2Hz, then perhaps I can use another component to lower that frequency again. Since I was told that the higher the crystal frequency I use (4Mhz or 10Mhz), the harder it is to have a lower frequency, I thought using a lower frequency closer to the one I want would be efficient enough for smaller frequencies. Have you heard of this before?
     
  11. ronv

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    Nov 12, 2008
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  12. MrChips

    Moderator

    Oct 2, 2009
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    No, no, no.

    Let's start over. Tell us exactly what frequency you want and to what accuracy.
    Then tell us why you need that particular frequency and why you need that accuracy.

    Then perhaps we can recommend a suitable solution.
     
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