Digital Clock on Breadboard (Circuit diagram Needed)

[atferrari]

a sundial would be far more accurate than a 555anddoes not slip10 30 minutes a month

the time base should be 1part per million error max or 1ppm in a XtalOsc for $1

how about an analog clock with LEDs?

1 secfrom /60
1m from next /60
1 hr from next /12
am/pm from next /2
multiply all these andthatbecomes your timebase
choose32kHz osc or similar to divide to timebase clock.

use Johnson counters (bunch) to drive LEDs directly using R's from each output so second+minute is twice as bright rather than separate LEDs. and hour +minute+second is 30mA. using 12V 300ohm driver from Johnson counters andR=620Ohms to Red LEDs or 560Ohms to Blue or White LEDs
Use smaller R's for minute and then smaller for hour for brighter indication. Choose >=50mA LEDs or increase R ratios. Temporary exceed suggested currents by 50% are ok for 1 sec, but not in direct sun. So further calc for R needed depending on selections of LEDs then buffers are needed for Johnson counters.

-choose SMT reelfor LEDs equally spaced in a circle cutting between LEDs to make arc andusing AWG 30 wire to solder to each isolated cut tracks on reelfor LEDs with a daisy-chained ground for each cathode (-) or use discrete >6000 mcd LEDs.

-cover front with tinted plastic or glass, so only the light is visible and not the wiring. frame with wood, or cosmetic material.

this primitive design will need at least a dozen chips but easy to figure out.use external DC jack for 12V power.

Make it big enough to be visible from outside (water tight) for a long a distance as needed. It can run from solar panel with 12V battery too.

Two weeks ago, I helped my brother with modern LEDs for a truck model. I was surprised: with just 1mA they were shining brightly. I started to consider them for something as the above.

 

[Tony Stewart]

Yes with 10 to 20Cd 5 mm LED at 20mA is blinding up close and at 5% If , or 1mA , it is adequate for most. Considering 5% of 20Cd is 1000mcd which is still 100x brighter than avg. 1985 LEDs

 

[granddad]

Potatoes...Favorite are Charlotte , At this latitude we plant in March / April , cover with fleece in May, harvest in late June, eat immediately ! Clocks ... Can't have too many this one waters my greenhouse tomatoes, favorite are Marmande, between 09:00 and 18:00 every 3 hrs ( prog in EE ) Its a PIC24FV16KA302, 12v 3.2A battery lasts a couple of months between charge , MOSFET switches a bilge pump .

 

[Tony Stewart]

you're smart granddad, some rookies try to design a SMPS to drive 2Hz.cycle Gulper water pump

 

[Tabish Syed]

Hello , Syed Faizan Ali ...

You need a help ... Here is the circuit Diagram