Clock Module

My first project using more than 3 IC's :p This project was made to understand various modes of 555 times mostly in terms of multi vibrators, there are all 3 types of multi vibrators used in this model, and a series of digital logic to make its function possible.

Function:

Its main function was to provide a working signal AKA Clock signal which is series of up and down or one and zeros and most accurately 0v and 5v. this helps the computer and all its parts to work synchronously with each other, as there are modules which completes their work in 4 clock cycles. so the other module should know to stop for 4 cycles before sending data on bus, as it may interfere.

Also the clock signal controls the speed of computer. The faster the clock the faster the computer will work. 

There was also a need for debug method as if the clock was fast or even slow but incontrollable I couldn't debug the circuit on every step thus a small but complex circuit using 555 timer IC's.

Circuit:

Circuit Design

It contains 3 555 timer IC's.

1. First one is in astable mode making the clock work indefinitely with desired frequency set by using the variable resistor and a capacitor

2. Second one is in monostable mode, so that I can pulse the clock on my desire using a button, also a normal button could have been used but a normal button has a problem known as debouncing  (it is the phenomenon which occurs due to a metallic strip inside the button which might produce ripples causing unwanted clock cycles) so to avoid that I used monostable state of 555 timer.

3. And to interchange b/w these two I required a signal which stays on, on both sides thus using bistable mode of 555 times and finally the digital circuit to use it.

This was one of the most important pieces of my computer but definitely not the hardest. Still as this was the first piece that I built I wanted to learn a few things too with this so I created a PCB model so that I can understand the standards and design perspective of PCB design, and it did help me.

PCB Design

My circuits weren't that good looking on the breadboard back then as I was not in possession of wires of quality and perfect sizes. Whatever I had I used it.

Thank you for reading if  you find this helpful do let me know and if you have any query feel free to ask in the comments.