The next step for Ahmed Mohamed
How to design your own digital clock from 4000 series CMOS chips.
Dave reverse engineers a DIY clock he built back in the 1980's as a teenager (he lost the schematics, twice!)
Before the days of microcontrollers, cheap PCB's, and internet mail order parts, you built stuff on veroboard using discrete parts from your junk bin salvaged from old teardowns.
Does it use Texas Instruments chips from Radio Shack? 😀
Schematic: http://www.eevblog.com/files/DigitalClockSchematic.pdf'>http://www.eevblog.com/files/DigitalClockSchematic.pdf
Forum: http://www.eevblog.com/forum/blog/eevblog-801-how-to-design-a-digital-clock/'>http://www.eevblog.com/forum/blog/eevblog-801-how-to-design-a-digital-clock/
Datasheets of all your favourites:
https://www.fairchildsemi.com/datasheets/CD/CD4013BC.pdf
http://www.nxp.com/documents/data_sheet/HEF4040B.pdf
http://www.ti.com/lit/ds/symlink/cd4518b-mil.pdf
http://www.ti.com/lit/ds/symlink/cd4026b.pdf
http://www.ti.com/lit/ds/symlink/cd4511b.pdf
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How to design your own digital clock from 4000 series CMOS chips.
Dave reverse engineers a DIY clock he built back in the 1980's as a teenager (he lost the schematics, twice!)
Before the days of microcontrollers, cheap PCB's, and internet mail order parts, you built stuff on veroboard using discrete parts from your junk bin salvaged from old teardowns.
Does it use Texas Instruments chips from Radio Shack? 😀
Schematic: http://www.eevblog.com/files/DigitalClockSchematic.pdf'>http://www.eevblog.com/files/DigitalClockSchematic.pdf
Forum: http://www.eevblog.com/forum/blog/eevblog-801-how-to-design-a-digital-clock/'>http://www.eevblog.com/forum/blog/eevblog-801-how-to-design-a-digital-clock/
Datasheets of all your favourites:
https://www.fairchildsemi.com/datasheets/CD/CD4013BC.pdf
http://www.nxp.com/documents/data_sheet/HEF4040B.pdf
http://www.ti.com/lit/ds/symlink/cd4518b-mil.pdf
http://www.ti.com/lit/ds/symlink/cd4026b.pdf
http://www.ti.com/lit/ds/symlink/cd4511b.pdf
EEVblog Main Web Site: http://www.eevblog.com
The 2nd EEVblog Channel: http://www.youtube.com/EEVblog2
Support the EEVblog through Patreon!
http://www.patreon.com/eevblog
EEVblog Amazon Store (Dave gets a cut):
http://astore.amazon.com/eevblogstore-20
T-Shirts: http://teespring.com/stores/eevblog
Donations:
http://www.eevblog.com/donations/
Projects:
http://www.eevblog.com/projects/
Electronics Info Wiki:
http://www.eevblog.com/wiki/
💗 Likecoin – Coins for Likes: https://likecoin.pro/ @eevblog/dil9/hcq3
Done.
hey, thats how people used to prototype back in the day. If you were fortunate you would make this nest with wire wrap. Its just how things were done but the stuff worked.
Even as a beginner hobby engineer who doesn't grasp concepts like ground and impedance well, I was able to follow along and work out some ideas, great video!
HI DAVE THAT PART OF STEELING THE UNIQUE SIGNAL FROM THE SIX TO GET THE RESET GREAT THINKING,IT WAS A STEEL AND I LOVED EVERY MINUTE OF IT IM DESGRACED AS I USED 2 4017s FOR THE 60 RESET WITH MINE I WORY ABOUT THE COUNT ON THE SIXTY GOING WRONG BUT WITH YOUR GENIUS IDEA YOU DONT HAVE TO WORY AS YOURS WILL AUTOMATICALLY BE ACCURATE, EXCELLENT IDEA AND A VERY RELIABLERESET, ID LIKE TO MAKE ONE AND STEEL YOUR IDEA FOR THE RESET AS I HAVE THE HEAD SCRATCHED OFF MYSELF LOL,OUT OF A LOT OF CLOCKS I LIKE YOURS BY FAR THE BEST THANKYOU FOR EVERYTHING YOUVE TOUGHT US OVER THE YEARS
I think it needs an ESP32 so you can connect to it from your phone and view the time remotely. You could even charge other people who want to access it. Call it Time-as-a-service. Now go get some VC funding and wait to get acquired!
/s
I'm confused…so it doesn't support Bluetooth? /s
Very clever!
How have I not seen this one before? A great project and sure as hell nothing to be embarrassed about. This is smashing stuff and shows you what you can do without PCB prototype fabrication and what not. Brilliant stuff!
Can't find words to thank you Dave!
Can't we also use the LOAD pin of the BCD counter IC (if it has one) to load a 1 to the first hour counter and and just CLEAR pin of the tens hour counter to get 01 after 12 ,by kind of decoding 12 ?
I did a few projects like this. I was more of a 74xx ttl and 555 timer fanboy. 4xxx series cmos chips were not all that robust ( perhaps in my hands). That mains strain relief is still a lot better than nothing.
Wow Dave, that's so genius of you to design and build that digital clock with CMOS logic
Great design and teaching moment! I too am obsessed with scratch-built clocks.
Couple of bucks for 2 resistors ? You must have been rich 🤣
Builds digital clock when he was a teenager
Grew up to invent a 32 channel logic analyser
Dave, When you were building this clock, I was designing stuff for a major electronics company in USA. Love the diode gates!!
Hey Bob, have you seen that big stash of wire I left over here in the corner? I swear I saw it there yesterday!
HOw does the minute get a signal if you are resetting the previous chip at 59.9 since the 5 never gets to 10., or does the chip send the signal when it resets.. Im assuming that the signal for the minute is comming from the same line as the reset request rather than the carry on the chip?
Can it be adapted from 50Hz to 60Hz clock? cheers!
NO!!! Its not embarrassing. Its something to be proud of!!!