Digital Clock using DC supply

Thread Starter

Anthony Quah

Joined Dec 1, 2007
Hey guys, need some help here.. i am not actually study electronic but i am interested to built my own Digital Clock using flip flop ( prefer D-flip flop) ..can anyone of you been thru design Digital clock using flip flop send me the circuit i can built 1?

I doing do net searching myself.. i am using below item for my Digital Clock..hope more help can be given especially the circuit diagram..
1. 7 segment
2. D flip flop
3. BCD decoder



Joined Apr 27, 2007
Planning to use NAND gate..
Logic family refers to the technology used in the chip. You can choose several logic families. Here are the most important:
74LSxx - Low power schottky;
40xx/45xx - CMOS;
74HCxx - High speed CMOS.

You can see the characteristics of these families here:

If you are using discrete logic, then use the gate combination that allows the use of less chips. For example, you can use a NAND gate as a NOT gate, a NOR gate the same way, or two NAND gates as a AND gate, and so on, and so on... Google for De Morgan's laws.