This is part 1 of 3 videos by Dr. Ali Shirsavar from Biricha about Input Capacitor sizing and selection for switch mode power supplies.
In this video we talk about why we need input capacitors, what roles ceramic capacitors and electrolytic capacitors play and we will show on an oscilloscope, how the noise on our input voltage changes with varying amount of capacitance.
In part 2 (next video) we will show exactly how to calculate the amount ceramics and electrolytics that we need for a given specification.