Digital Clock without Microcontroller

Description

Table of Contents:

  1. Digital Clock without Microcontroller
  2. Calculations
Contributor: 
I.V.Shravan

Digital clocks normally function by microcontrollers. Here is a circuit for electronic enthusiasts who can make a digital clock without using any expensive controllers, or having no knowledge of microcontrollers or programming. The whole functioning is solely based on simple IC’s.

 
Components used
IC 555 (Timer) --- one.
CD4518 (CMOS dual up counter) --- two.
74LS47 (7-segment display driver) --- four.
7-segment displays --- four.
Basic Gates (AND, OR).

Working
The clock for the circuit is provided by 555 timer in astable mode (with on-time 2 secs and off-time 58 secs).With every positive edge of timer’s output, one of the counters of CMOS dual up-counter CD4518 (right one in fig.) is clocked, and a BCD output is obtained on the pins 3 to 6. These are given to 7-segment display driver 74LS47 that drives the minute’s display. When the count reaches 9, the other counter of the same IC is clocked, and the current counter is reset. When 59th minute is reached for any hour, the next increment in counter will reset the whole IC, and clock the hour counter (CD4518). When 23 hours is reached, any increment in the hour counter will reset it. The whole set-up can be turned on by pressing S1. The user can adjust the time by pressing on the switches S2 (hours) and S3 (minutes). The on-time of 555-timer is made 2 seconds so that the user doesn’t have any problem in adjusting the time.
 
 

Circuit Diagram

Comments (8)

realy nice project. but

Submitted by qqq on Fri, 31/08/2012 - 00:30.

realy nice project. but 'please' provide detail information about it.....

realy nice project. but

Submitted by krunal21293 on Tue, 16/10/2012 - 08:59.

realy nice project. but 'please' provide dip detail information about it.....

sir  i want make reverse

Submitted by sageer2 on Mon, 18/02/2013 - 18:28.

sir 

 i want make reverse digital clock so i want use down couter (or any other idea how to make it ) .

and to make it using CD4518 counter sir i need your help

 

share me more about digital

Submitted by Sayanti Sinha on Thu, 21/03/2013 - 12:49.

share me more about digital clock project

The circuit is so badly drawn

Submitted by poriet on Wed, 10/04/2013 - 02:23.

The circuit is so badly drawn it's unreadable!

Can you redo it so I can decipher it

can you send me the complete

Submitted by phantomhives on Wed, 01/05/2013 - 01:49.

can you send me the complete schematic clear diagram please, thanks. here's my email lagazo_jake@yahoo.com

yes its a good work... 

Submitted by asadsohail12 on Thu, 16/05/2013 - 09:09.

yes its a good work...

 

bari meharbani  

Submitted by Waqar_bora on Thu, 16/05/2013 - 20:45.

bari meharbani

 

 

You are her