DEAR ANYONE,

:?: I need a schematic diagram of a digital clock using simple 74xx ICs I'm a college student and i still dont have much knowledge about building a digital clock. I need it for my project in electronics laboratory. Preferably using 7490,7447, and the like....please ops:

thanks in advance!! :shock:

 

one can build a digital clock with a row of 4 or 6 7 segment displays or one can build one with 60 + 12 LED's in a circle, which is it you are interested in?
Your biggest bugbear - if you want the clock battery operated - is the obtaining of a stable frequency from a 1 Mhz crystal or such. All the clock chips with onboard oscillators are not TTL logic.
If you can use the mains frequency as a clock pulse source it is somewhat easier but there's no power off time keeping facility.
Klaus

 

Take a look at this one:
http://users.otenet.gr/~athsam/samgordon_clock_eng.htm

Greetings,
Hannes.

 

i need a your design

 

Well.

Do your own bloody work!

__________________
I also post at the following sites:
http://www.stop-microsoft.org http://www.heated-debates.com
Screen name: Aloone_Jonez
And http://www.silicontronics.com, same screen name as here.

 

You won't learn much if you don't attempt it yourself.

We are here to help, but not do it all for you.

__________________
Len

 

Hi Shreik,

Search the forum, you'll find more clocks than you can handle.

http://www.electro-tech-online.com/e...d-circuit.html

on1aag.

 

Now this one is school work. I hope no one sent him a direct link to one ..

Come on man..

If he did not learn enough in school to build it AND can not work google..

Practice this, "would you like to super size your order?". (I sound like hitech and Hero wants to club him.)

 

Hiya! Nice to be back in this forum.

Lol, I didn't thought on1aag referred a link to my thread, how nice yet embarrassing. XD

But yeah, sometimes you have to do it yourself than others do it all for you. I mean, after on1aag gave the rest of the schema, I felt like "damn, I'm relying on others again". But I did studied his schema and figure out how he did it and spent hours on my breadboard. Good thing I didn't get callouses after that, hehehe And there's a thing that I've been "trying too hard" figure out how to set the hour hand to 12-hour instead of 24 (our instructor issued us a challenge that if we can figure out to set the clock to 12-hour format instead of 24-hour, we're exempted on a written exam), until I reached the point that it's impossible for a 74LS90 IC. Maybe someone here can, who knows? The thing is that I did my what I can, but on my own.