What is SMPS

SMPS(switched-mode power supply)

SMPS means Switch Mode Power Supply.As the name suggests it is used to switch the Alternating Current(AC) voltage into Direct current (DC) voltage which is required for our computer systems to work.It is placed inside the C.P.U of our computer and from this SMPS connections are given to the CD/DVD drive,Hard disk and to all parts of the computer. 

Function of SMPS is similar to the transformers that are seen on the streets near our houses.These transformers also convert AC into DC voltage and supply it to our houses.But we cannot place a transformer in our computers as space occupied is too large.So,SMPS are introduced in the place of transformers.It is very efficient and very low heat is produced by this. 

in general it is highly reliable and can guarantee you an efficient work up to 5 years.But if there is any fluctuation in your power line that will directly effect your SMPS and it may be damaged. 

SMPS can also be classified into four types according to the input and output waveforms, as follows. 

AC in, DC out: rectifier, off-line converter 
DC in, DC out: voltage converter, or current converter, or DC to DC converter 
AC in, AC out: frequency changer, cycloconverter 
DC in, AC out: inverter 
AC and DC are abbreviations for alternating current and direct current. 


Switched-mode PSUs in domestic products such as personal computers often have universal inputs, meaning that they can accept power from most mains supplies throughout the world, with frequencies from 50 Hz to 60 Hz and voltages from 100 V to 240 V (although a manual voltage "range" switch may be required). 

In the case of TV sets, for example, one can test the excellent regulation of the power supply by using a variac. For example, in some models made by Philips, the power supply starts when the voltage reaches around 90 volts. From then, one can change the voltage with the variac, and go as low as 40 volts and as high as 260, and the image will show absolutely no alterations.