Day 1- Astable Multivibrator

 We are starting from the basics- Astable Multivibrator. The internal structure of a 555 Timer IC consists of  2 comparators and a SR latch. 

Components:

1. 7805 IC

2. 555 Timer

3. Led

4. Resistors-220 ohm, 100k ohm, 1k ohm

5. capacitors- 1 microfarad, 0.01 microfarad, 0.1 microfarad

6. Connecting wires, Breadboard

Circuit Diagram:

Working:

I found the following source to be a great summarizer in addition to the video made by Ben Eater. It delved into the theory more.

https://youtu.be/iJYm_BGqa1A?feature=shared

Fig 2: Source- 'All about Electronics'

Inference:

• It works based on charging and discharging of the capacitor through the resistors.
• The voltage is compared and '0' or '1' is sent from the comparator.
• When S=1, R=0-> Q=1
• When S=0, R=1->Q=0
• When S=0,R=0->Q=previous state
• The charging and discharging results in a square wave output

Fig 3: Source- 'All about Electronics'

• The timing/frequency/duty cycle is fixed in order to know the value of the resistors/capacitor.
• The 4th pin in 555 Timer IC is made high so as to prevent the chip from accidental resets.
• To ensure smooth transition between high and low states, a 0.01 micro farad capacitor is used.
• To prevent accidental output overshoot, a 0.1 microfarad capacitor is used.