Transformerless Power Supply

Abstract

Power supply is an Electronic device that function to supply voltage on other electronic equipments that require a DC supply such as computer power supply and adapter. Power supply are transformator (trafo) step-down to lower AC voltage. When viewof the size of the power supply that uses transformer size is larger, to reduce the size and cost of making a power supply in final project the author makes a power supply without transformer where voltage reduction processed using a non polar X-capacitor with high voltage in parallel with resistor to withstand inrush current and next rectification by diodes to convert AC voltage to DC voltage. Power supply use IC 7812 produces a voltage output 12 Volt DC and used as an adapter for a 5 meters LED light strip.From the design results obtained the size of the power supply becomes smaller and cheaper.