Generating 1Hz frequency

[koolguy]

Hello Guys,
I am Electronic project of Clock with 1 Hz frequency to make Clock on Led 7 segment Display.
will 555 is better in astable mode or 4060??
here is similar video of projects.

 

[Les Jones]

Neither will be good enough for a clock time reference. Use a 32,768 khz crystal and divide it down by 2^15 using a 4060 followed by 4013 or use a 4521.

Les.

 

[jpanhalt]

Here is a lengthy thread by MR RB on generating a 1 Hz time base: https://www.electro-tech-online.com/threads/please-help-precision-1khz-sine-filter.119418/

He wanted much more accuracy than you need. Nevertheless, the thread should be useful to you.

John

 

[koolguy]

Neither will be good enough for a clock time reference. Use a 32,768 khz crystal and divide it down by 2^15 using a 4060 followed by 4013 or use a 4521.

Les.

I think this will be fine.
I am working on LED clock!

 

[dr pepper]

32.768 khz Watch crystals generally speaking tend to be much more accurate than crystals intended for logic/processors, and massively more accuarte than a 555 which would be very innacurate.

 

[koolguy]

But there will be one problem of power failure reset!

 

[KMoffett]

Gut a 1.5V battery operated wall/desk clock. They have an internal PCB (usually) that contains a crystal and an IC that outputs two 0.5 Hz pulses, 180 degrees out of phase. Summing these gives you very accurate 1Hz pulses. There is some variations of the ICs. Some have high with low going output pulses, others are low with high going pulses.


Ken

 

[crutschow]

But there will be one problem of power failure reset!

Power the clock generator and logic circuits with a battery (or battery backup).
Power only the LEDs from wall power.

 

[Tony Stewart]

I agree with KM. Quartz wall clocks are reliable and low power.

The challenge for you is to figure out how to calibrate it so that it is within 1 second per month using a Lithium cell for stable voltage.