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Hours timer with display - Options needed

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I didn't look at the datasheets, but my reolection is that the digit driver has to support 7 segments and the segment driver only supports 1.

In some chips it's expected that there is an external transistor for the digit drive.

Switching a chip from CA to CC and vice versa requires one to change the current direction at the digit and segment sides of the driver.
 
There used to be a chip that took a color burst crystal and created 1pps. I'm sure now that a 32768 KHz resonator can be divided to get 1 pps. You have to further divide it to get your required rate.
 
There used to be a chip that took a color burst crystal and created 1pps. I'm sure now that a 32768 KHz resonator can be divided to get 1 pps. You have to further divide it to get your required rate.

MM5369 took the 3.579545 MHz and gave you a 60 Hz. timebase then a simple 4017 got you down to 10 or 1 Hz. Was a pretty useful chip 30 years ago. :)

Color burst crystals were in abundance.

Ron
 
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I've spent the evening looking for an app note for the 4060 that included information on which crystal, resistor, and capacitor combinations provide what frequency. I didn't have any luck, it's not included in the standard datasheet. Anyone have any thoughts?
 
I got you to 1 Hz. This might get you further: https://cr4.globalspec.com/thread/37049/Divide-by-60-in-one-chip

0.1 hrs is every 6 minutes. So, 1 Hz divided by 60 gives you every minute. Divide by another 6, gives you every 6 minutes.

A divide by 60 is a divide by 2 in series with a divide by 5 in series with a divide by 6. Since, I think, the link a few posts back as a 0.5 Hz out, the div by 2 isn't needed.
 
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I've spent the evening looking for an app note for the 4060 that included information on which crystal, resistor, and capacitor combinations provide what frequency. I didn't have any luck, it's not included in the standard datasheet. Anyone have any thoughts?

hi,
Look at this datasheet.
 

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I saw that one too. No help. All they say about the crystal-based circuit is "In Fig.5, R2 is the power limiting resistor. For starting and maintaining oscillation a minimum transconductance is necessary."
 
I saw that one too. No help. All they say about the crystal-based circuit is "In Fig.5, R2 is the power limiting resistor. For starting and maintaining oscillation a minimum transconductance is necessary."

I would say there is enough information on this clip from the 4060 datasheet to get all you need for a crystal oscillator to work.????

Or are you asking about CMOS crystal circuits generally.??
 

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Read it closely, real close. It took me almost 10 minutes to understand what it was talking about and why it didn't make sense in reference to the figure next to it. Notice there is no mention of the crystal in the highlighted passage. That passage applies only to the RC network in figure 5.1, not the XRC network in figure 5.2.
 
Read it closely, real close. It took me almost 10 minutes to understand what it was talking about and why it didn't make sense in reference to the figure next to it. Notice there is no mention of the crystal in the highlighted passage. That passage applies only to the RC network in figure 5.1, not the XRC network in figure 5.2.

hi,
I would suggest these pdf's will give a complete picture of crystal osc's.
 

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  • HCMOS_osc.pdf
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  • cer_prin.pdf
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