Linear power supply converts high voltage alternating current into low voltage using a transformer and then converts it into direct current using a rectifier circuit. Switch mode power supply on the other hand converts AC into DC first and then changes the voltage to the desired level. High frequency switching of DC by MOSFET\/Power Transistor is done and output fed into a ferrite core transformer to step down the voltage. It is then rectified and filtered to give the final DC output. The bulk of this transformer is lower as it acts at high frequency than the 50 Hz of the conventional AC transformer. That is why an SMPS is quite light.<\/p>\n
While the efficiency of SMPS is above 65%, that of a linear power supply may be only 25-50%. The low efficiency of linear power supply is due to the ohmic loss in the voltage regulator circuit, which also needs a heat sink. SMPS does not need a heat sink as there is not much of power dissipation within it. SMPS is commonly used in mobile chargers. It can also be used for HF radio, accepting a likelihood of having more noise than a linear power supply and needs RF shielding to avoid RF interference produced by the switching process.<\/p>\n","protected":false},"excerpt":{"rendered":"
Linear power supply converts high voltage alternating current into low voltage using a transformer and then converts it into direct current using a rectifier circuit. Switch mode power supply on the other hand converts AC into DC first and then changes the voltage to the desired level. High frequency switching of DC by MOSFET\/Power Transistor […]<\/p>\n","protected":false},"author":1,"featured_media":862,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,4,5],"tags":[],"class_list":["post-861","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-amateur-radio-ham-radio","category-hobby-electronics","category-mobile-phones"],"yoast_head":"\n