SMPS (switching mode power supply)

First of all to start with let me give you the full form.S.M.P.S means switching mode power supply.It is also known as PSU(power supply unit),if you have a computer just look at the backside of the CPU you will be able see a huge fan which  basically helps the PSU'S from overheating.The amount of power delivered by this SMPS  depends upon your hardware specs,suppose you basically have a good amount of ram, processor, and a good GPU you will need to have a good quality SMPS which is of say 550V,this is the standard benchmark .In my case what happened is that I bought a Gpu (ATI Radeon HD 6570) which demands higher power and at that moment I had a 450volt SMPS.After injecting my newly aquired hardware I got excited and started playing hardcore games(my first on the list was crysis 3),but my excitation was soon put to end by my Smps which was unable to deliver power and due to which  there was unexpected shutdown everytime I played the game for 5mins.So I had to change my SMPS.



        I bought this SMPS, which is super cool and works with absolutely zero noise.You can buy it too and be safe for the future.          
In extreme cases overheating may cause fire so don't risk it if you experience the same problem. Anyway in this post my objective is to make you understand how a S.M.P.S works,so lets get started.......

In SMPS the input is A.C mains ant the output is D.C.The isolation between the input and output is required.The working of a SMPS can be perfectly understood by the block diagram.

As you can see from the above block diagram the ac mains are first rectified and the rectifier output is smoothed by using a filter and after that smoothed dc is switched at high frequency(typically about 50khz).Smps uses a high frequency MOSFET as a switching transistor with varying duty cycle of the chopper to maintain the output voltage.The switched current flows in the primary circuit of the transformer(for more information please refer to my post about basic idea of a transformer) .After this secondary current from the transformer is rectified and smoothed.And as I have mentioned earlier the control of the output voltage is obtained by the adjustment of  the chopper duty cycle.The main objective of the smps is to convert electrical power efficiently and to transfer power from a source to a load.Smpses can also be used to step down a supply voltage which a transformer alone can do though smpses comprises transformer as  you can see from the above figure.

The above procedures is followed by a basic SMPS.However there are several  types of SMPS which are:

• Buck or forward converter
• Bbuck-boost converter
• Boost or flyback converter
• Pushpull converter
• Cuk converter
• Resonant converter
• Half-bridge and Full-bridge converters

The choice of SMPS is basically driven by our power needs.Here only the basic idea of SMPS is given.Working of the types of SMPS is more complex but if you know how it works you will be able to understand all those damn converters.Happy Reading!!!