# [HELP]Digital Clock composed of Logic Gates assembled using Electronic Workbench

#### pr1111

Joined Jul 8, 2010
35
hi!!! I'm a newbie and I need help in my project....

we need to design a digital clock using logic gates

the schematic must be done on the program Electronic Workbench

the schematic of the digital clock must be working

#### SgtWookie

Joined Jul 17, 2007
22,221
Where's your schematic? Did you forget to attach it?

Or do you want someone to do it for you?

Since this appears to be a homework assignment, it belongs in the "Homework Help" forum.

#### pr1111

Joined Jul 8, 2010
35
i need someone to help me with the schematic

#### pr1111

Joined Jul 8, 2010
35
the one i need is composed of logic gates

#### JoeJester

Joined Apr 26, 2005
4,390
the one i need is composed of logic gates
Do you know what a block diagram represents?

#### pr1111

Joined Jul 8, 2010
35
no,,, how can i use that block diagram???

#### JoeJester

Joined Apr 26, 2005
4,390
Block diagram is a diagram of a system, in which the principal parts or functions are represented by blocks connected by lines, that show the relationships of the blocks.

That block diagram is an overview of the circuits you will need to successfully make your digital clock.

It breaks your project into some smaller functions so you can work on have lots of little successes on the way to the big success of the project.

#### Wendy

Joined Mar 24, 2008
22,374
Given that many chips are functionally equivalent to a block (mod 10 or mod 6 counters can be 7490 or 7492 for example) it does help break it up into manageable chunks, in many cases one or two chips.

Is this homework?

#### pr1111

Joined Jul 8, 2010
35
it's a project... we are currently studying boolean algebra and we are not yet taught about this things...

#### Wendy

Joined Mar 24, 2008
22,374
So if I said you needed a mod6 counter do you know what I'm talking about?

#### pr1111

Joined Jul 8, 2010
35
no... how can i make a mod 6 counter and mod 10 counter??

#### pr1111

Joined Jul 8, 2010
35
how does the divided Hz on each counters affect the clock??

#### JoeJester

Joined Apr 26, 2005
4,390
it's a project... we are currently studying boolean algebra and we are not yet taught about this things...
The "we" you speak of are your other team members I assume. Is this a college project?

#### Wendy

Joined Mar 24, 2008
22,374
Simple, there are many chips off the shelf that will do it without any extra logic, I've already named two, but TTL is pretty old, so you may need/want something else.

Mod refers to the total count a specific counter has. A mod6 counter has 6 counters, then starts over (usually but not always straight binary). Ditto with mod10 counters. Between the two counts that comprises 90% of the counters in a clock.

The gates you are currently learning contribute to the final counter, the mod12 or mod24 version.

You have some serious reading in front of you, no help for it. I would recommend breadboard each part on a protoboard or your simulator, once you finish the section then save it for later use.

A good display decoder is something like the 7447 or 4511. How to use them is in the data sheet.

You may have selected an advanced project and may be over your head. If you enjoy this kind of problem solving it can be fun though.

What part of the world are you? You'll note the older experienced members have included it in their profile, it can help with finding parts.

A mod6 counter is a straight ÷6 function, 60 Hz in, 10 Hz out.

#### pr1111

Joined Jul 8, 2010
35
yes it's a college project... i have a subject called logic circuits and switching theory.. our current topics are the boolean algebra and de morgan's law... i don't have any idea on how to make a digital clock from logic gates... our teacher want us to research about it in advance and make one even if our knowledge and his lessons are not yet enough

#### pr1111

Joined Jul 8, 2010
35
I'm from the Philippines

#### Wendy

Joined Mar 24, 2008
22,374
Look for specific chips, and match them on the block diagram. Are you planning on a crystal oscillator or power company for the time base (50 or 60 Hz)? Do not assume we know your local power specs, it is entirely country dependent.

You will find this group helpful, but for college projects we tend to guide you to where to find the information, it does you no good to get a premade schematic. If you post a schematic we'll help you find the weak points or where it isn't working.

#### pr1111

Joined Jul 8, 2010
35
ok.. so i want to have a mod 6 counter that counts from 0 to 6 i need 4 flip-flops right... what kind of flip-flop do i need to use??our power supply in the philippines is 220V 60Hz... how does the logic gates going to affect the schematic of the clock??

#### Wendy

Joined Mar 24, 2008
22,374
Again, unless you want this to take up a ½ a meter or so square board space, you can get chips that are already mod6 and mod10 right off the shelf. If you really want to use individual flip flops that will work, it will just be bigger. Even with the mod6/mod10 chips it will still be pretty big. If you really want to go basic you could always use NOR or NAND gates, but I don't recommend it.

I'll be back, but it is bed time for me.