Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe

Digital Clock without Microcontroller

By I.V.Shravan May 11, 2012

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.
 
 

Calculations

Calculations
On-time of 555 = 20K ohm * 100 uF = 2secs.
Off-time of 555 timer = 580K ohm * 100uF =58secs.
0.01uF at pin 5 (control pin) of 555 timer is to eliminate the electromagnetic noise. The 100 ohm resistor common to switches S2 and S3 are used as pull-down resistors. 333 ohm resistors and other 100ohm resistors are used to limit the current.
Diodes are small-signal diodes IN4148.

 

Project Source Code

 

Circuit Diagrams

Digital-Clock-without-microcontroller-Circuit


Filed Under: 555 Timers, Electronic Projects
Tagged With: 555 timer circuit, clock, digital clock
 

Next Article

← Previous Article
Next Article →

Questions related to this article?
👉Ask and discuss on EDAboard.com and Electro-Tech-Online.com forums.



Tell Us What You Think!! Cancel reply

You must be logged in to post a comment.

EE TECH TOOLBOX

“ee
Tech Toolbox: 5G Technology
This Tech Toolbox covers the basics of 5G technology plus a story about how engineers designed and built a prototype DSL router mostly from old cellphone parts. Download this first 5G/wired/wireless communications Tech Toolbox to learn more!

EE Learning Center

EE Learning Center
“engineers
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for EE professionals.

HAVE A QUESTION?

Have a technical question about an article or other engineering questions? Check out our engineering forums EDABoard.com and Electro-Tech-Online.com where you can get those questions asked and answered by your peers!


RSS EDABOARD.com Discussions

  • Thermal modelling of repetitive power pulse
  • Redundant XORs
  • No Output Voltage from Voltage Doubler Circuit in Ansys Nexxim (Harmonic Balance Simulation)
  • Discrete IrDA receiver circuit
  • ISL8117 buck converter blowing up

RSS Electro-Tech-Online.com Discussions

  • Help with finding unique wire lug(s)
  • Simple LED Analog Clock Idea
  • Kawai KDP 80 Electronic Piano Dead
  • Saga 1400sv vinyl cutter motherboard issue
  • using a RTC in SF basic

Featured – LoRa/LoRaWan Series

  • What is the LoRaWAN network and how does it work?
  • Understanding LoRa architecture: nodes, gateways, and servers
  • Revolutionizing RF: LoRa applications and advantages
  • How to build a LoRa gateway using Raspberry Pi
  • How LoRa enables long-range communication
  • How communication works between two LoRa end-node devices

Recent Articles

  • What is the LoRaWAN network and how does it work?
  • Understanding LoRa architecture: nodes, gateways, and servers
  • Revolutionizing RF: LoRa applications and advantages
  • How to build a LoRa gateway using Raspberry Pi
  • How LoRa enables long-range communication

EE ENGINEERING TRAINING DAYS

engineering

Submit a Guest Post

submit a guest post
Engineers Garage
  • Analog IC TIps
  • Connector Tips
  • Battery Power Tips
  • DesignFast
  • EDABoard Forums
  • EE World Online
  • Electro-Tech-Online Forums
  • EV Engineering
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • 5G Technology World
  • Subscribe to our newsletter
  • About Us
  • Contact Us
  • Advertise

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy

Search Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe