4060 timer calculation

Discussion in 'The Projects Forum' started by Andra, Dec 25, 2014.

  1. Andra

    Thread Starter New Member

    Dec 22, 2014
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    I am building a circuit with a 4060 counter that I'd like to have a 60 minute cycle. How do I calculate the resistor and capacitor values I need at pins 9, 10, and 11? I know the resistors at pin 10 and the capacitor at 9 determine the oscillation, but what does the resistor at 11 do, and what are the ideal ranges for each of these?
     
  2. ScottWang

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    Aug 23, 2012
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    When I start to use the CD4060 that I never using RC to generate the frequency, if you want to using RC to do then you can see the IC 4060 Design Note.

    The below is 1Hz crystal oscillator, it is linking from my blog.
    [​IMG]
     
  3. ronv

    AAC Fanatic!

    Nov 12, 2008
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  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Do you want an output that is 30sec high and then 30sec low, or do you want a narrow pulse every 60sec?
     
  5. Andra

    Thread Starter New Member

    Dec 22, 2014
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    I am looking for 30 minutes high 30 minutes low, to start and reset a monostable 555 every hour.
     
  6. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    The second option mentioned by MikeML seems good for you, saving a 2nd chip.

    Oh, wait. What the 555 has to do?
     
  7. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi,
    I single 4060 osc will not give you a 30 minute timing period, its too long.

    Look at the HEF or CD4521, IC.
    E
     
  8. k7elp60

    Senior Member

    Nov 4, 2008
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    According to Don Lancaster in his book,"CMOS COOKBOOK". The resistor on pin 11 should be greater than 10 times the reistor on pin 10. The value of the resistor and capacitor connected to pins 9 & 10 is calculated by t(time)=2.2RC. Since the greatest division of the 4060 is 16384, if you multiply 30 minutes by 60(seconds/min)=1800 seconds. The divide 1800/16384 we get .10986 seconds The oscillator time. Then .10986=2.2R1uF. R=.10986/(2.2x1uf). R=49.93k. The other resistor needs to be greater than 500k ohms. I would like to point out that the time may not be very accurate as the value of the capacitor and the applied voltage will affect the accuracy.
     
  9. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    If the period of the output is 3600 sec (1800 sec high, 1800 sec low), then the period of the oscillator would need to be 3600/16384 = 0.21973 sec.

    Here is the RC oscillator right off the data sheet:

    rc.gif

    I calculate that if Rx=100K, Rs can be 470K, and Cx would be 1uF
     
  10. Wendy

    Moderator

    Mar 24, 2008
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    I've designed quite a few 4040 and 4060 circuits. I usually use a 555 to drive a relay for power applications, but this is not always needed.

    Describe what you are driving and the on/off time of the pulse. You also need to think about accuracy, you can do this with one 4060 and a RC clock setup (part of the 4060) or with a crystal oscillator, your choice. The RC method is around 5% accurate, not very good but adequate for a lot of applications and definitely fewer parts.
     
  11. Andra

    Thread Starter New Member

    Dec 22, 2014
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    I am using the 555 to turn on an LED, and I'm not too worried about accuracy. What is the difference between an RC and a crystal setup?
     
  12. Wendy

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    Mar 24, 2008
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    Complexity and accuracy. A crystal can be used in a digital clock (12:00AM), where a RC clock is very loose (+/- 10%, maybe worse, depends on the effort you spend), but needs a LOT less parts.

    A 4060 with a watch crystal can make a very accurate 2Hz signal, which you would then drive a second 4060 circuit with.

    A RC 4060 can use just one chip (plus the 555 timer).
     
  13. #12

    Expert

    Nov 30, 2010
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    I did this with an LS7210. Very similar to a 4060 chip, but allows for programming both time constants (on time and off time). Figure 6
     
  14. k7elp60

    Senior Member

    Nov 4, 2008
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    The difference in this case is the frequency. With the RC the oscillator is at about 4.5Hz. With a crystal about the lowest frequency available for a small cost is 32.768Khz. You don't need a 555 to turn on the LED or other device with the 4060. Depending upon the current required a transistor will work fine.
     
    Last edited: Dec 27, 2014
  15. Wendy

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    Mar 24, 2008
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    Side note, I am assuming a 32.767Khz crystal (a watch crystal). A 4060 has a max division of 1/2 that, 16384. If you divide a 60 minute cycle (hz = (60*60)) by the 16384 you would need a base frequency of 4.55hz. So you would probably need a second 4060 if you chose to go the crystal method.
     
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  16. Wendy

    Moderator

    Mar 24, 2008
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    A 555 has the advantage of setting a set on time independent of the 4060. I have several tested circuits drawn up in other posts is the OP is interested. It caught my interest, I satisfied my interest, I moved on. :)

    The other chip sounds interesting, but I keep 4060's in my parts kit. And lots of 555's.

    To the OP: Me and 555s are an in joke on this site. I dearly love that little chippie.
     
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  17. Brevor

    Active Member

    Apr 9, 2011
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    Hi #12, Interesting you used that IC, LSI/MSI is kind of an obscure company but they make a lot of unique IC's.
    Funny story, 20 some years ago I was looking to use some of their IC's in a custom product I was designing. I checked with the company for a local distributor. Turns out there was one located less than 1 mile from where I worked. I called them to place an order and since they were so close, could I just stop by and pick them up? "sure just stop in " was the answer, the address turned out to be a small house in a residential neighborhood. The guy took me down to the basement where he had a shelf full of tubes of IC's. He filled my order while I watched, I paid and left. He said this was just a small part time job he did to supplement his regular job.
     
  18. #12

    Expert

    Nov 30, 2010
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    I bought that chip from Radio Shack, long before I knew about this site or online vendors. Somewhere in the 1990's IIRC.

    The point is, it was convenient to get this chip at that time. That's probably the major reason I used it.
     
    Last edited: Dec 27, 2014
  19. Brevor

    Active Member

    Apr 9, 2011
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    After reading your post I became curious so I looked the company up and they are still around. They still sell that LS7210 IC you used , and that guy I bought the samples from is still listed as a distributor at the same address.
     
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