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I am making a CMOS logic clock and I have a problem with the 1Hz signal generator (see schematic below). When I connect up the CD4060BE chip to a crystal the output on Q8 of the second chip does not blink an LED at 1Hz, but rather the LED stays permanently lit (I don't have a scope to test the frequency). I connected up a 3Hz CMOS clock to the clock input on the second CD4060BE chip and Q8 blinks the LED at the same rate as the input frequency. Why would this happen? Surely the input frequency should be divided down by 2^8 and the LED blink should be extremely slow. Am I doing something wrong?

1HZ Clock Signal Generator

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  • \$\begingroup\$ Your schematic does not show an LED. From your question it is apparently driven by Q8 of U3. Exactly how is this done? \$\endgroup\$
    – Math Keeps Me Busy
    Commented Jan 3, 2021 at 17:12
  • \$\begingroup\$ Doh! I plugged the LED in the wrong way around. Thanks. \$\endgroup\$
    – Mario Gianota
    Commented Jan 3, 2021 at 17:24
  • \$\begingroup\$ Your crystal connection circuit looks flaky to me. I don't think that will work very well (well, not according to the data sheets). What made you decide on that way of doing it? \$\endgroup\$
    – Andy aka
    Commented Jan 3, 2021 at 17:43
  • \$\begingroup\$ @Andy aka I copied it from a YouTube video demonstration of a CD4060BE 1Hz clock circuit. Do you have a pointer to the correct way of doing it? \$\endgroup\$
    – Mario Gianota
    Commented Jan 3, 2021 at 17:45
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    \$\begingroup\$ The device data sheet shows how you should do it. \$\endgroup\$
    – Andy aka
    Commented Jan 3, 2021 at 17:46

1 Answer 1

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I plugged the LED in the wrong way around to test the output on Q8. Stupid error. Thanks.

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