digital clock circuit?

[christopher whitehead]

does anyone know where I can get a circuit diagram for making my own digital
clock? At the moment I have tried doing on crocodile clips with 4 bcd to 7
segment decoders and 4 decade counters but it's not very good. Having
trouble resetting the count, especially the nought and one digit on the hour
side.

 

[petrus bitbyter]

does anyone know where I can get a circuit diagram for making my own digital
clock? At the moment I have tried doing on crocodile clips with 4 bcd to 7
segment decoders and 4 decade counters but it's not very good. Having
trouble resetting the count, especially the nought and one digit on the hour
side.

Decade counters are good for the LSD of the hours and the minutes. For the
MSD of the minutes you need a divide by six counter, for the MSD of the
hours a divide by two counter will do. So for instance you can use two 7490
type decade counters and one 7492 type divide by twelve counter. The latter
contains a divide by six and a divide by two counter.

petrus

 

[Tim Shoppa]

does anyone know where I can get a circuit diagram for making my own digital
clock?

Most typically would be done today with a small programmable microcontroller.
There are special-purpose IC's that are available through typical repair
parts sources, too, like the NTE2046 and NTE2062.

At the moment I have tried doing on crocodile clips with 4 bcd to 7
segment decoders and 4 decade counters but it's not very good. Having
trouble resetting the count, especially the nought and one digit on the hour
side.

Do you desire a 1-12 count, a 0-23 count, or something else? Defining
the problem is more than half the solution in this case.

Tim.

 

[Luhan Monat]

does anyone know where I can get a circuit diagram for making my own digital
clock? At the moment I have tried doing on crocodile clips with 4 bcd to 7
segment decoders and 4 decade counters but it's not very good. Having
trouble resetting the count, especially the nought and one digit on the hour
side.

You need to use counters that have parallel loading to get this to work.
Even then, it should be a very 'educational' experience.

You may try posting to sci.electronics.basics with this question.

 

[Bill Bowden]

does anyone know where I can get a circuit diagram for making my own digital
clock? At the moment I have tried doing on crocodile clips with 4 bcd to 7
segment decoders and 4 decade counters but it's not very good. Having
trouble resetting the count, especially the nought and one digit on the hour
side.

It could be done with a $3 microcontroller such as PIC16F628,
but if you want to use descrete logic chips, there is a plan here:

http://ourworld.compuserve.com/homepages/Bill_Bowden/dclock.htm

There is also a binary clock that requires less parts.

-Bill

 

[christopher whitehead]

wow, thanks for the help. Obviously I am never going to get a job doing this
stuff!

Happy new year. May your jk flip-flop trigger levels rise and fall in sync.